section [0.72em] \thecontentslabel. \contentspage\titlecontentssubsection [0em] \thecontentslabel. \contentspage\titlecontentssubsubsection [0em] \thecontentslabel. \contentspage
Family Floer superpotential’s critical values are eigenvalues of quantum product by
Abstract
Abstract: In the setting of the non-archimedean SYZ mirror construction in [Yua20], we prove the folklore conjecture that the critical values of the mirror superpotential are the eigenvalues of the quantum multiplication by the first Chern class. Our result relies on a weak unobstructed assumption, but it is usually ensured in practice by Solomon’s results [Sol20] on anti-symmetric Lagrangians. Lastly, we note that some explicit examples are presented in the recent work [Yua22a].
1 Introduction
The mirror symmetry phenomenon does not merely focus on the Calabi-Yau setting. Assume that a compact symplectic manifold is Fano (or more generally that is nef). The mirror of is expected to be a Landau-Ginzburg model consisting of a space equipped with a global function called the superpotential. In the context of the homological mirror symmetry [Kon95], a celebrated folklore conjecture states that: (known to Kontsevich and Seidel, compare also [She16, §2.9])
Conjecture 1.1.
The critical values of the mirror Landau-Ginzburg (LG) superpotential are the eigenvalues of the quantum multiplication by the first Chern class of .
The conjecture is first proved by Auroux [Aur07] in the Fano toric case, concerning the Landau-Ginzburg mirror associated to a toric Lagrangian fibration in [CO06, FOOO10a].
Theorem 1.2.
Conjecture 1.1 holds for the family Floer mirror Landau-Ginzburg superpotential.
See §1.1 for the precise statement. In brief, we aim to prove the conjecture with nontrivial Maslov-0 quantum correction, and actually we don’t need to be limited to the family Floer scope. It looks like a “small” step to include Maslov-0 disks, but it is indeed difficult and requires some new ideas (§1.2). We also find new examples recently in [Yua22a] to justify and amplify the value of this paper.
The symplectic-geometric ideas we use are not original, but it is not our main point at all. Instead, a major point in this paper is to demonstrate that the classical ideas fit perfectly into the framework of the family Floer mirror construction in [Yua20]. For example, a key new ingredient for our proof is a preliminary version of “Fukaya category over affinoid coefficients” (i.e. the self Floer cohomology for in §3). Roughly, the coefficient we use is not , not the Novikov field , but an affinoid algebra over . The merit is that we can ignore all the affects of Maslov-0 disk obstruction up to affinoid algebra isomorphism on the coefficients using the ideas in the author’s thesis [Yua20]. We expect the affinoid coefficients should be important to develop Abouzaid’s family Floer functor [Abo17, Abo21] with Maslov-0 corrections. A work in progress is [Yua]. For the above speculative version of Fukaya category, one might study many topics like splitting generations [AFO+] and Bridgeland stability conditions (cf. [Smi17] [Kon]) in some similar ways in future studies. We also expect that it is related to the non-archimedean geometry, like the coherent analytic sheaves, on the family Floer mirror space, potentially being the analytification of an algebraic variety over the Novikov field. But unfortunately, the precondition of all the story is to allow the Maslov-0 disks in the course. Otherwise, we cannot even realize a simple algebraic variety like as a family Floer mirror space and thus miss the new examples of Conjecture 1.1 in [Yua22a].

(1) What is the difficulty of allowing Maslov-0 corrections?
First and foremost, the family Floer mirror superpotential is only well-defined up to affinoid algebra isomorphisms, or equivalently, up to family Floer analytic transition maps [Yua20]. This is because the Maslov-0 quantum correction give rise to certain mirror non-archimedean analytic topology. Note that the idea of uniting Maurer-Cartan sets, adopted by Fukaya and Tu [Fuk09, Fuk11, Tu14], cannot achieve the family Floer mirror non-archimedean analytic structure. We must go beyond their Maurer-Cartan picture; otherwise, although Fukaya and Tu did tell the correct local analytic charts, the local-to-global gluing was only set-theoretic. In fact, we never think of bounding cochains but work with formal power series in the corresponding affinoid algebra directly [Yua20]. One of many crucial flaws in the previous work concerns the lack of studies of the divisor axiom for structures111The earliest literature we find for open-string divisor axiom is due to Seidel [Sei06]. See also [Aur07, Fuk10].. The ud-homotopy theory developed in [Yua20] is indispensable for the mirror analytic gluing. Remarkably, the ud-homotopy theory plays the key role for the folklore conjecture once again (cf. §1.2).
Putting another way, we must work with the minimal model algebras, while paying attention to the wall-crossing phenomenon simultaneously (Figure 1). Without minimal model algebras, the superpotential would be only -valued and was not well-defined. This issue was not so fatal if the Maslov indices , but it is indeed fatal if we allow Maslov-0 correction. As another evidence, a minimal model algebra is intuitively like counting holomorphic pearly-trees (cf. [FOOO09]) which are also used in Sheridan’s proof of HMS of Calabi-Yau projective hypersurfaces [She15, §6.2]. The conventional ideas of the folklore conjecture cannot work or need to be improved for holomorphic pearly-trees or minimal model algebras, if nontrivial Maslov-0 disks exist (Figure 1). A daunting trouble is to handle the minimal model algebra’s Hochschild cohomology (see §1.2).
(2) Why does the family Floer method give a convincing approach to construct the mirror?
The answer in short is simply that we can prove the Conjecture 1.1 supported by examples below.
Gross and Siebert proposed a method of mirror construction in the algebro-geometric framework [GS11] based on the SYZ proposal [SYZ96]. Gross-Hacking-Keel [GHK15] also give a synthetic algebro-geometric construction of the mirror family for local Calabi-Yau surfaces. These approaches turn out to be successful in many aspects, such as [HK20, GHK13, GHKK18]. But, in our biased opinion, the folklore Conjecture 1.1 inevitably relies on Floer-theoretic or symplectic-geometric ideas in the end. The family Floer mirror construction [Yua20] can naturally include the Landau-Ginzburg superpotential. Such a Floer-theoretic mirror construction succeeded in rigorizing the T-duality of smooth Lagrangian torus fibration with full quantum correction considered, and leads to a mathematical precise statement of SYZ conjecture with singularities in [Yua22a, Yua22b, Yua23].
1.1 Main result
Let be a symplectic manifold which is closed or convex at infinity. Let . Let be an oriented, spin, and compact Lagrangian submanifold satisfying the semipositive condition that prohibits any nontrivial negative Maslov index holomorphic disk. In practice, a graded or special Lagrangian submanifold is always semipositive by [Aur07, Lemma 3.1]. Note that is not necessarily a torus. Given an -tame almost complex structure , we can associate to a superpotential function
(1) |
where we use the minimal model algebra
of the cochain-level algebra associated to . Here we work over the Novikov field , is a formal symbol, so . The reverse isoperimetric inequality [GS14] ensures that converges on an analytic open neighborhood of in .
Although the summation in (1) runs only over Maslov-2 topological disks , it actually can involve all the possible Maslov-0 obstruction in the same time. This is simply the nature of minimal model algebras, and the idea is illustrated in Figure 1. In general, allowing the Maslov-0 disks, the superpotential function is not well-defined and rely on the various choices like . But, as in [Yua20] (see Lemma 2.6), we can show that the is well-defined up to affinoid algebra isomorphism, and we can also show that the critical points and critical values are preserved.
Assumption 1.3.
The formal power series222It is related to the weak Maurer-Cartan equations in the literature, but we forget the latter and only think . vanishes identically.
Notably, the recent results in [Yua24] provide strong support for considering the above assumption reasonable, and it is likely that the assumption holds in many situations. It does not say that the counts of Maslov-0 disks vanish. These disks still contribute to both the minimal model algebras and the wall-crossing phenomenon, but their contributions ultimately cancel out in the coefficient affinoid algebra. Moreover, it is not a restrictive assumption. Thanks to the work of Solomon [Sol20], a very useful sufficient condition of the above Assumption 1.3, which we often adopt in practice, is given as follows:
Assumption 1.4.
There is an anti-symplectic involution that preserves .
Indeed, such a gives a pairing on via . Then, the Maslov-0 obstruction terms in are then canceled pairwise. In practice, such an involution is often not hard to find (see also [CBMS10]). Note that the vanishing of does not rely on due to [Yua20]. Beware that we have not discuss the family Floer setting or the SYZ setting at this moment. Note also that we do not require is a torus here. Now, we state the main result.
Theorem A (Theorem 5.5).
Under Assumption 1.3, if the cohomology ring is generated by , then any critical value of is an eigenvalue of the quantum product by . Moreover, the same result still holds if we use different choices.
The main new progress and difficulty is that we allow Maslov-0 holomorphic disks. It is conceivable that if the above lives in a family of Lagrangian submanifolds , then one may extend the domain of to a larger open analytic space. Up to the Fukaya’s trick, this amounts to study how depends on the choice of . Recall that is only invariant up to affinoid algebra isomorphisms. This is because of a sort of ‘quantum fluctuation’, when we think of the minimal model algebra together with the wall-crossing phenomenon in the meantime (see Figure 1).
1.1.1 Family Floer mirror construction setting
As a byproduct of the above Theorem A, we can verify the family Floer mirror superpotential in [Yua20] respects Conjecture 1.1. We first briefly review it. Suppose is a symplectic manifold which is closed or convex at infinity. Suppose there is a smooth Lagrangian torus fibration in an open subset in over a half-dimensional integral affine manifold . Suppose that is semipositive in the sense that any holomorphic disk bounding a fiber has a non-negative Maslov index. By [Aur07], a sufficient condition is to assume -fibers are graded or special Lagrangians. For simplicity, we also require that the -fibers satisfy Assumption 1.3 or 1.4. Then, we state the result of SYZ duality with quantum correction considered:
Theorem 1.5 ([Yua20]).
We can naturally associate to the pair a triple consisting of a non-archimedean analytic space over , a global analytic function , and an affinoid torus fibration such that the following properties hold:
-
i)
The analytic structure of is unique up to isomorphism.
-
ii)
The integral affine structure on from coincides with the one from the fibration .
-
iii)
The set of closed points in coincides with .
Notice that this mirror construction uses holomorphic disks in rather than just in , and we should place inside to understand the statement. For simplicity, we often omit the subscripts ’s, so we often write , if there is no confusion. The ud-homotopy theory and the category in [Yua20] is indispensable for the non-archimedean analytic topology in Theorem 1.5. The usual homotopy theory can only achieve a gluing in the set-theoretic level. Very intuitively, the family Floer theory is ‘algebrized’ by the category , and the choice issues are all controlled by the ud-homotopy relations in .
Theorem B.
Roughly, by allowing the wall-crossing invariance, we can enlarge the domain of the superpotential and so potentially cover more eigenvalues. But, we cannot conversely conclude that all the eigenvalues of are realized by a critical point of the superpotential. Note that the -coefficients in include the data of symplectic areas and can tell which chambers the critical points are situated in. In particular, the locations of critical points depend on the symplectic form .
1.2 A new operator for Hochschild cohomology and ud-homotopy theory
The obstructions in Lagrangian Floer theory cause issues for both analysis and algebra. The analysis part should be of most importance and difficulty, concerning the complicated transversality issues of moduli spaces of pseudo-holomorphic curves. This is studied and developed by [FOOO10b, FOOO10c, FOOO20] and so on. In comparison, the algebra part should be minor. But, in our biased opinion, the intricacies and subtleties of the algebra part are somewhat underestimated.
The open string Floer theoretic invariants often depend on choices. Thus, we often must talk about certain equivalence relations, depending on which the information we miss can vary. For example, in the literature like [FOOO10b], we usually talk about algebras up to homotopy equivalence. It is fine in most cases, but it may be too coarse in case we need more information (e.g. non-archimedean analytic structure). The homotopy equivalence relation cannot distinguish between a minimal model algebra and its original. This is why the usual Maurer-Cartan picture [Fuk09, Fuk11, Tu14] cannot be enough for a local-to-global gluing for the family Floer mirror analytic structure, as explained before.
In our specific situation here for the folklore Conjecture 1.1, we must carefully distinguish between a minimal model algebra, denoted by , and its original, denoted by . This is because the classic ideas for the folklore conjecture can only achieve connections between the quantum cohomology and the cochain-level Hochschild cohomology . Meanwhile, the family Floer Landau-Ginzburg superpotential comes from the minimal model algebra .
There are some new challenges. For instance, the Hochschild cohomology is just not functorial, and in pure homological algebra, it is basically impossible to make any meaningful connections between the Hochschild cohomologies of a minimal model algebra and its original. Fortunately, in our specific geometric situation (with Assumption 1.3 or 1.4), we magically make an effective connection by the following operation (see (53))
where is the composition (see [She15]), the is the celebrated brace operation (see [Get93]), and the is the ud-homotopy inverse of the natural homotopy equivalence in the course of homological perturbation. A difficult part of the paper is to find the above operation and establish the corresponding computations. As far as we know, such does not appear in any literature and seems to be exclusive for our ud-homotopy theory in [Yua20].
Now, the ud-homotopy theory shows its necessity again. Moreover, it is interesting to note that the family Floer mirror analytic gluing in [Yua20] does not exploit the full information of ud-homotopy relations, while the techniques in the present paper (e.g. the self Floer cohomology for in §3) use more information of ud-homotopy relations.
1.3 Outline and major difficulties
If the Maslov indices , the approach to Conjecture 1.1 is well-known to experts for a long time: see [Aur07, §6] or [RS17, §12.1] in toric cases and [FOOO19, §23] in general; see also [She16, Definition 2.3]. Roughly speaking, a key idea concerns a unital ring homomorphism
(2) |
from the quantum cohomology to the self Floer cohomology through the Hochschild cohomology. But, when nontrivial Maslov-0 disks are allowed, we cannot obtain such a unital ring homomorphism as usual. It is even necessary to find a suitable way to generalize the definitions of and in (2). The major difficulties are outlined as follows.
i
We want the self Floer cohomology to be defined in a ‘wall-crossing invariant’ way.
This is especially crucial for the global result, and we note that is not necessarily a torus here.
First, thanks to the Fukaya-Oh-Ohta-Ono’s foundation works, we can very generally define the self Floer cohomology by choosing any odd-degree weak bounding cochain . However, it may be too general for our purpose. We want to work with a more restrictive situation, highlighting the semipositive condition and the wall-crossing phenomenon. By utilizing the related ideas about the category , we define a modified self Floer cohomology for any cohomology-level algebra in (§3). It is a unital -algebra, and it does not refer to a specific weak bounding cochain. Instead, whenever admits a lift of weak bounding cochain in via , we may define in almost the same way as the above ; moreover, it may be viewed as the restriction of at the point , accompanied by a natural unital ring homomorphism .
Our modified Floer cohomology are wall-crossing invariant in the following sense. Recall that an analytic transition map is determined by an homotopy equivalence in . Then, the and can induce an isomorphism as well. Further, we have the following: When the de Rham cohomology ring is generated by (e.g. is topologically a torus), the is non-vanishing if and only if is a critical point of , where is the local superpotential defined by as before. This result also has the wall-crossing invariance. Set and ; not only but also we know that if is a critical point of , then is a one of and vice versa. Finally, we remark that the non-archimedean analysis plays an important role for this result: Let be a lower bound of the energies of nontrivial holomorphic disks, then we should first show the result modulo and inductively refine it to for . The limit for the adic topology in the Novikov field as works in the end.
ii
The definition of in the middle of (2) becomes problematic and ambiguous.
This issue is actually more difficult than (i). The moduli spaces of holomorphic disks first only give the chain-level algebra . In contrast, the self Floer cohomology and the superpotential all resort to the cohomology-level , i.e. the minimal model algebra. Previously, when the Maslov indices were , the homological perturbation largely degenerates so that the difference between and is mild enough to achieve (2). Unfortunately, when the Maslov-0 disks are involved, such difference cannot be ignored, and the subsequent discrepancy between the two Hochschild cohomology rings and becomes highly nontrivial. For instance, there is basically no chance to make a ring homomorphism between the two of them, as the Hochschild cohomology is neither covariant nor contravariant. This obstacle leads to a peculiar mismatch between the algebra and geometry. The moduli spaces with interior markings can produce a ring homomorphism from the quantum cohomology only to the chain-level Hochschild cohomology but not to the cohomology-level one .
In a word, the solution can be realized by the relevant technologies about the category introduced both in this paper and in [Yua20]. Not only the homological algebra but also the non-archimedean analysis and the geometric semipositive condition in are used in a significant way. Briefly, we will carefully design a map between the underlying two Hochschild cochain complexes such that: although it does not precisely induce a ring homomorphism, the gap to become so is controlled by the ud-homotopy relations in . Next, applying a natural projection map , this gap is then controlled by the weak Maurer-Cartan formal power series and eliminated under Assumption 1.3. We can ultimately show that the composition map can induce an honest unital ring homomorphism (§5).
2 Preliminaries and reviews
The Floer theory usually works over the Novikov field . It has a valuation map , sending a nonzero series to the smallest with and sending the zero series to . The Novikov ring is the valuation ring whose maximal ideal is . The multiplicative group of units is . Note that and . The standard isomorphism naturally extends to . In particular, for any , there exists some with .
Let , and we consider the tropicalization map
(3) |
The total space should be understood as not just an algebraic variety over but also a non-archimedean analytic space. Roughly, a non-archimedean analytic space is a locally ringed space whose structure sheaf is locally given by affinoid algebras. Affinoid algebras are quotients of the Tate algebras. The spectrum of an affinoid algebra is called an affinoid space or affinoid domain. Let be a rational polyhedron in , then the preimage is an affinoid (sub)domain in . We refer to the appendix in [Yua20] or the standard textbook [Bos14, Ber12] for further readings.
Lemma 2.1.
vanishes identically if and only if .
Proof.
Let . Note that i.e. . Arguing by contraction, suppose the sequence was nonzero, say, it had a maximal value for some . May further assume . Then, for all , so . Modulo the ideal of elements with norm , we get a power series over the residue field . As , we have and for . Hence, this is just a Laurent polynomial over with . Meanwhile, the condition also tells that vanishes for all ; thus, must be identically zero. This is a contradiction. ∎
2.1 Gapped algebras and the category
We revisit the notations and terminologies from [Yua20, §2], along with introducing some new concepts where necessary. While there are slight differences in the formulations, similar notions have been previously introduced in [FOOO10b] and [Fuk10].
2.1.1 Gappedness
A label group is a triple consisting of an abelian group and two group homomorphisms and . For instance, let and denote a symplectic manifold and a Lagrangian submanifold, then we may take (or more precisely, is the image of Hurewicz map ); the and are the energy and Maslov index.
Assume are graded -vector spaces. Given and , we use the notation to denote a copy of where is just an extra index. Then, consider the space
(4) |
consisting of the operator systems satisfying the following gappedness conditions:
-
(a)
;
-
(b)
if or , , then vanishes identically;
-
(c)
for any , there are only finitely many such that and .
Here a collection of multilinear maps is called an operator system . If it is further contained in , namely, it satisfies the above three conditions, the is called (-)gapped. Unless we further specify, everything is gapped from now on. We often abbreviate it to .
2.1.2 Signs and degrees
Define the shifted degree for . It is convenient to set
(5) |
Given and a multi-linear map , we put
where denotes the -iteration of . If , we set . Let be the usual degree as a homogeneously-graded -multilinear operator among graded vector spaces. Then, the shifted degree is . Note that .
We define the composition (see [She15, Definition 2.39]) and the Gerstenhaber product (see [Ger63])
(6) | |||
The gappedness ensures that they are finite sums. For instance, if could be non-zero, the sum in would have infinite terms and was not well-defined.
2.1.3 structures
By a -gapped algebra , we mean an operator system in such that and , namely
A -gapped homomorphism from to is an operator system such that and , namely
As is always an even integer, we know and in . Restricting the or to the energy-zero part (i.e. ), what we obtain is called the reduction (resp. ) of (resp. ). In the energy-zero part, we always have and . Hence, an algebra naturally induces a cochain complex and an homomorphism also induces a cochain map . Applying the homological perturbation to yields a new algebra with , often called the minimal model.
Let be the convex hull of finite points in a Euclidean space such like a -simplex . Denote by the set of all smooth maps from to , and we define
It naturally comes with the evaluation map
for any and the inclusion map
Alternatively, it can be regarded as the space of -valued differential forms on . For instance, when for a manifold , we have a natural identification via . Also, the and are the pullbacks for the inclusion and the projection .
A -pseudo-isotopy (of gapped algebras) on is simply a special sort of a gapped algebra structure on such that the is -linear (up to sign) and the is the canonical differential on . In the special case , the coincides with the exterior derivative . The notion of pseudo-isotopy is introduced in [Fuk10]. See also [Yua20] for the details.
2.1.4 Unitality and divisor axiom
An arbitrary operator system is called cyclically unital if, for any degree-zero element and any , we have
On the other hand, a gapped algebra is called (strictly) unital if there exists a degree-zero element 1, called a unit, such that
-
1.
-
2.
-
3.
for .
Assume and have the units and 1; then, a gapped homomorphism is called unital if and
for .
A gapped algebra is called a quantum correction to de Rham complex, or in abbreviation, a q.c.dR, if is for some manifold so that , , and for . Geometrically, an algebra obtained by the moduli spaces or any of its minimal model can satisfy the q.c.dR conditions.
From now on, we always assume and or for some and . In either of two cases, we have a natural differential on for which there is a well-defined cap product on
for any . Now, we say an operator system in satisfies the divisor axiom if for any and ,
2.1.5 The category
Given a symplectic manifold , let be an oriented spin Lagrangian submanifold. We remark that is not necessarily a Lagrangian torus. Set . For simplicity, we use a uniform notation 1 to denote all various constant-one functions in either or . In [Yua20, §2], we introduced a category as follows:
-
(I)
An object in is a -gapped algebra with the following properties:
-
(I-0)
it extends or ;
-
(I-1)
the constant-one function is a (strict) unit;
-
(I-2)
the cyclical unitality;
-
(I-3)
the divisor axiom;
-
(I-4)
it is a -pseudo-isotopy;
-
(I-5)
every in the set satisfies .
-
(I-0)
-
(II)
A morphism in is a -gapped homomorphism with the following properties:
-
(II-1)
the strict unitalities with the constant-one functions as units;
-
(II-2)
the cyclically unitality;
-
(II-3)
the divisor axiom;
-
(II-4)
for any divisor input ;
-
(II-5)
every in the set satisfies .
-
(II-1)
We also call (I-5) and (II-5) the semipositive conditions. We write and for the collections of objects and morphisms in respectively.
2.1.6 Homotopy theory and Whitehead theorem
For , there is the notion of ud-homotopy: We call
are ud-homotopic if there is
such that
where is the trivial pseudo-isotopy about and can be proved to be an object in as well. In this case, we write . Moreover, if and only if there exists and in such that: (see [Yua20, §2])
-
(a)
Every ;
-
(b)
;
-
(c)
The satisfies the divisor axiom, the cyclical unitality, and for all ;
-
(d)
. For every with , we have .
In the context of , we also have the Whitehead theorem [Yua20, §3]:
Theorem 2.2 (Whitehead).
Fix such that is a quasi-isomorphism of cochain complexes. Then, there exists , unique up to ud-homotopy, such that and . We call a ud-homotopy inverse of .
2.2 An observation about weak Maurer-Cartan equations
The semipositive condition (I-5) says that for , we have only if . Hence, . If the is defined on , then we may write as in [Yua20]:
(7) |
Remark 2.3
The moduli space of holomorphic disks bounding a Lagrangian submanifold gives an algebra on at first. But, we need to use its minimal model . Otherwise, the first summation in (7) would live in and may not be in the form of .
Let denote the ideal in generated by the components of . The ideal vanishes under Assumption 1.3, but let us keep it for a moment to highlight the ideas. Basically, one may view (7) as the (weak) Maurer-Cartan equations with certain differences. We review the following lemma whose proof is also implicitly given in [Yua20]:
Lemma 2.4.
Proof.
Let and be as in §2.1.6 with the conditions (a) (b) (c) (d) therein. For a basis of , we have . For a basis of , we write , and then by definition, the ideal is generated by all the . By Lemma 2.1, it suffices to restrict
to an arbitrary point in . We can write for . We set for the basis. Applying the divisor axiom of and the condition (b) implies that
Since , the semipositive condition and the cyclical unitality of deduce that the second summation vanishes. Hence, for the operator , it follows from the condition (c) that
Now that the above equation holds for any , it also holds identically by Lemma 2.1. ∎
2.3 Wall-crossing from family Floer viewpoint: Review
Here we review the wall-crossing aspect of the family Floer framework in [Yua20]. In this section, we provide a summary of the basic points and refer to [Yua20] for the details.
2.3.1 structures
Let be an -tame almost complex structure in . Fix and with . We consider the moduli space of the equivalence classes of -boundary-marked -holomorphic genus-zero stable maps with one boundary component in in the class . Let denote the collection of the moduli spaces for all . We call a moduli system. Using the virtual techniques [FOOO20], it gives rise to a chain-level algebra denoted by . Suppose is semipositive in the sense that there does not exist any -holomorphic disk in with negative Maslov index. Then, one can check that is an object in .
The family Floer theory only works with the cohomology-level algebras; see e.g. Remark 2.3. We need to perform the homological perturbation to the above . Let be a metric. By the Hodge decomposition, one can find two cochain maps , of degree zero and a map of degree such that , , , , and . Now, we call the harmonic contraction. Applying the homological perturbation with this , the algebra induces its minimal model denoted by . It is an object in and also accompanied by a morphism in . Next, for a path of metrics , there is a parameterized harmonic contraction ; further using the parameterized moduli spaces for a path , we can naturally produce an homotopy equivalence in such that . It always comes from a pseudo-isotopy, and it does not depend on various choices up to the ud-homotopy relation.
2.3.2 Analytic coordinate change maps
We take an adjacent Lagrangian submanifold in a Weinstein neighborhood of such that there exists a small isotopy supported near such that . Choose a tautological 1-form on such that vanishes exactly on and . Then, one can use the Stokes’ formula to show for any and . Note that is a closed one-form on . Conventionally, we distinguish between and due to the energy change, but we may feel free to identify with for adjacent fibers.
By [Fuk10], Fukaya’s trick essentially refers to the observation of a natural correspondence between a -holomorphic curve with boundary on the Lagrangian and an -holomorphic curve with boundary on .
Convention 2.5.
We say is an homotopy equivalence up to the Fukaya’s trick, if it is an homotopy equivalence in from to such that and the algebra is defined in view of Fukaya’s trick by
In practice, such a is obtained in almost the same way as §2.3.1 but further using the Fukaya’s trick.
Suppose is an homotopy equivalence in up to the Fukaya’s trick as above. We write and as in (7) for and respectively. We write
(8) |
By the semipositive condition, we know any nonzero . By the gappedness, . The following lemma describes the wall-crossing phenomenon precisely.
Lemma 2.6 ([Yua20]).
The assignment defines an isomorphism
(9) |
such that . Moreover, this map only depends on the ud-homotopy class of . Under Assumption 1.3, we actually have and
We use the formal symbols and to distinguish the monomials in and respectively, where . From a different perspective, the coordinate change map corresponds to a rigid analytic map
(10) |
where the domain is usually a proper subset but always contains by Gromov’s compactness. When is identified with , and we often take the domain to be a polytopal affinoid domain for a rational polyhedron in , c.f. (3). Concretely, the image point in is such that for , where the denotes the image of under the pairing . Further, chosen a basis, this means . One can check that whenever , we have . The above lemma tells that . Conventionally, the will be called a (family Floer) analytic coordinate change.
3 Self Floer cohomology for the category
3.1 Non-curved structures
3.1.1 Definition
Fix a cohomology-level algebra (§2.1.5). We define
(11) |
where we can further extend each by linearity so that the is -linear. The is actually -linear, since whenever . Also, the semipositive condition (§2.1.5) tells that if for some . Remark that since we really use higher Maslov indices like here, there may be more information extracted from than in [Yua20].
Be cautious that by (7) is only available in the cohomology level (Remark 2.3). To develop a non-curved algebra, we need to exclude in our consideration. Notice that the coefficient ring may be replaced by some quotient ring. Although the ideal vanishes under Assumption 1.3, we retain it to preserve a more general framework. The vanishing of becomes relevant only when considering the derivatives and critical points of .
Proposition 3.1.
The collection forms a (non-curved) algebra over .
Proof.
The associativity of deduces that for all pairs . It implies that for any fixed . Therefore,
The reasons are as follows. First, all of -terms are collected on the right, which forms . Recall the ideal is generated by the components of , so (mod ). Finally, the unitality of deduces that for every . ∎
Corollary 3.2.
, , and
|
Definition 3.3.
The self Floer cohomology of (associated to ) is defined to be the -cohomology:
(12) |
Moreover, defines a ring structure on with a unit .
Note that we may also replace the formal power series ring by any polyhedral affinoid algebra contained in it. Since , the is at least -graded.
Suppose is an homotopy equivalence up to the Fukaya’s trick in the sense of Convention 2.5 with respect to an isotopy such that . Consider the two non-curved algebras and obtained as in Proposition 3.1 using the two gapped algebras and respectively. By virtue of Lemma 2.6, there is an -induced isomorphism . Similar to (11), we define
(13) |
where all the formal power series coefficients in will be afterward transformed to those in via the isomorphism . Note that , c.f. (8). Recall that the collections and exclude and . Similarly, we set excluding as well.
Proposition 3.4.
The gives a (non-curved) homomorphism from to .
Proof.
The associativity equations tells (c.f. Convention 2.5). Hence,
(14) |
for any fixed . On the left side, the terms involving form the series as in (8). Besides, since the components of are contained in , the divisor axiom of can be applied after we use Lemma 2.1. Therefore, the left side of (14) becomes:
On the other hand, using Lemma 2.6 yields that:
(Be careful to distinguish from .) In summary, the left side of (14) further becomes:
Now, in the right side of (14), we collect all those terms involving first, and their sum is equal to
But, and , and the above summation vanishes by the unitality of . To conclude, what remain on the right side of (14) are precisely as follows:
Applying to the two equations above, we complete the proof. ∎
Remark 3.5
It is worth mentioning that the equation (14) in the above proof assumes . In contrast, the gluing analytic coordinate change maps developed in [Yua20] (i.e. Lemma 2.6) essentially uses the same equation as (14) but only for . Therefore, we really use more information about the category here. Compare also Remark 3.7.
3.1.2 Invariance
In particular, Proposition 3.4 tells that and . Therefore, we know that is a cochain map and further induces a -algebra homomorphism
(15) |
Proposition 3.6.
The only relies on the ud-homotopy class of in .
Proof.
We basically use the ideas in [Yua20]. Suppose are two homotopy equivalences from to up to the Fukaya’s trick in about some isotopy (Convention 2.5). Suppose also that they are ud-homotopic to each other. Our task is to prove .
By definition, there exist operator systems and for such that the conditions (a) (b) (c) (d) in §2.1.6 hold, where and . By the condition (b), we get
(16) | ||||
The second and third sums are all zero modulo due to the condition (c) and the decomposition (7). The fourth sum vanishes because the semipositive condition ensures and we can use the cyclical unitality. For the fifth sum, the semipositive condition also tells ; by the divisor axiom and by Lemma 2.1, we conclude that the fifth sum is equal to
Then, since , it follows from Lemma 2.4 that (mod ), where we recall the notation in (8). Hence, by Lemma 2.6, after we transform into -coefficients, this fifth sum is
To conclude, only the first and fifth sum in (16) survive. Now, we set . Taking the integration from to and applying to the both sides of the initial equation (16), we exactly obtain that . In other words, the gives a cochain homotopy between the two cochain maps and . Particularly, the induced morphisms on the cohomology are the same . The proof is now complete. ∎
3.1.3 Composition
Now, we consider three adjacent Lagrangian submanifolds , and . Let and be small isotopies such that and . Suppose and are homotopy equivalences in up to Fukaya’s tricks. By Proposition 3.4, they give rise to two non-curved homomorphisms and . By Proposition 3.4 again, the composition gapped morphism in also induces a non-curved homomorphism, denoted by . We call it the composition of and . The notation and term we use here can be justified as follows:
Proposition 3.8.
The non-curved homomorphism satisfies that
Proof.
In particular, the above proposition infers that is also a cochain map; hence,
(17) |
Corollary 3.9.
In the context of Proposition 3.6, the is an isomorphism.
3.2 Evaluation of self Floer cohomology
3.2.1 Background and review
In the literature, the self Floer cohomology is defined by a different way. Here let’s assume has no torsion part. Instead of in Proposition 3.1, we previously work with and consider a weak bounding cochain , i.e. for the constant-one function . Then, we define
By condition, the will be eliminated. It is known in the literature that (see e.g. [FOOO10b, Proposition 3.6.10]): The collection forms a (non-curved) algebra on . Then, the self Floer cohomology is usually defined by .
3.2.2 Evaluation at a weak bounding cochain
For the family Floer theory and SYZ picture, we should mainly focus on those degree-one weak bounding cochains in . Indeed, if is a Lagrangian torus fiber in the SYZ framework, its dual torus fiber is expected to be , at least at the topological level. Now, we want to make connections with in (12). In fact, since , the divisor axiom of implies that
and we can even actually require instead of without violating the convergence. There is a quotient map induced by . For a basis of , we write for ; the image point is given by for . In general, let be the image of under the natural pairing . We also pick a basis so that . For and , we have . Now, we can introduce a slight variation of the above as follows:
(18) |
Note that (7). By the divisor axiom and under the semipositive condition, if and only if the admits a lift which is a weak bounding cochain. Hence, by the transformation , it simply goes back to the previous . Nevertheless, the advantage of (18) is that we can further allow to run over a small neighborhood of in .
Proposition 3.10.
If , then forms a non-curved algebra on .
Proof.
We may argue just as Proposition 3.1 by the associativity and the unitality of . ∎
Particularly, , so we can define the self Floer cohomology of at :
(19) |
As before, we can also show that defines a ring structure on with a unit . Additionally, we can consider the evaluation map at :
(20) |
where and . For the sake of convergence, we should replace by some polyhedral affinoid algebra in it, and we also require each coefficient is contained in the corresponding polyhedral affinoid domain. But, let’s make this point implicit for clarity. Here we also assume admits a weak bounding cochain lift up to Fukaya’s trick, namely, . Thus, the above also descends to a quotient map modulo , which is still denoted by . Further, we can extend the definition of by setting , , , and we can directly check the following:
Lemma 3.11.
The gives a non-curved homomorphism from to . Moreover, the induced map is a unital -algebra homomorphism so that .
Suppose is an homotopy equivalence up to the Fukaya’s trick for a small isotopy with (Convention 2.5). For the analytic map in (10), the point also admits a weak bounding cochain lift , i.e. . Then, we get two non-curved algebras and on and by Proposition 3.10. Just as (13), we define
(21) |
Proposition 3.12.
The collection forms a (non-curved) homomorphism from to so that . In particular, we have and .
Proof.
The proof is just the same as that of Proposition 3.4. ∎
Proposition 3.13.
The similarly induces a -algebra homomorphism which only relies on the ud-homotopy class of in . In particular, if admits a ud-homotopy inverse, then is an isomorphism.
3.3 Critical points of the superpotential
Take a formal power series in (where and ). Given , we define the logarithmic derivative along of by
(22) |
One can easily check the following properties: (a) ; (b) . Given an ideal in , we denote by
(23) |
We note that , whenever .
Suppose we have an homotopy equivalence in up to the Fukaya’s trick about a small isotopy such that (Convention 2.5). Recall that by Lemma 2.6, the analytic coordinate change map
is an isomorphism such that . Recall that and are given as in (7) for and respectively. Regard or as a principal ideal, we can define or just like (23).
Proposition 3.14.
The analytic coordinate change map match the ideal with .
Proof.
Suppose and are -related. First, we compute the commutator of and applied to a monomial :
Note that is contained in by (8). Next, we compute
For a fixed , we observe that the second sum over can be further simplified as follows:
Thus, is contained in the (extension) image ideal , so . By Lemma 2.6, the inverse can be defined by the same pattern as (9) using a ud-homotopy inverse of . Hence, we can similarly obtain that . Putting them together, we conclude . ∎
Definition 3.15.
We call a critical point of if is contained in the convergence domain333When we substitute into , the result is a series in the field . We require that it converges with respect to the non-Archimedean norm; see [Bos14, Page 10, Lemma 3]. and for any .
Corollary 3.16.
is a critical point of if and only if is a critical point of . Thus, in Theorem 1.5, the critical points of are well-defined points in the mirror analytic space .
3.4 Non-vanishing of self Floer cohomology
For the lemma below, the basic ideas already exist in the literature, e.g. [FOOO10a, Lemma 13.1], [FOOO16, Lemma 2.4.20], [FOOO12, Theorem 2.3]. But, we want some slight modifications in our settings. Let be a minimal model algebra obtained by the moduli space of holomorphic disks and by the homological perturbation. Recall that and agrees with the wedge product up to sign.
Define the from as in (11).
Lemma 3.17.
Suppose the de Rham cohomology ring is generated by . Let in be generators. For any , there exist such that
By [MS12, Proposition 4.1.4], for a sufficient small number , any nontrivial holomorphic disk in satisfies
(24) |
In the first place, we prove a weaker statement as follows:
Sublemma 3.18.
Assume the same conditions in Lemma 3.17. For any , there exist such that
Proof.
We perform induction on . When , , so . When , we write , and it follows from the divisor axiom of that
(25) |
Suppose the lemma is true for degrees . When , we may write for some by assumption, so . Recall that . Therefore,
(26) |
By (24), if , we must have . Hence, . By Corollary 3.2,
(27) |
Due to (25) and the unitality of , the first term on the right side is given by
(28) |
On the other hand, the induction hypothesis implies that there exist such that modulo . Then, using the equations (27, 28) with in place of there, we deduce that the second term on the right side of (27) is
Putting things together, we get
In conclusion, if , we set for and . The induction is now complete. ∎
Proof of Sublemma 3.18 Lemma 3.17.
We note that is actually -linear by definition. Repeatedly using Sublemma 3.18 implies that for various series ,
modulo the ideal . Then, it follows that
Since , the summations are convergent for the adic topology. ∎
Theorem 3.19.
Suppose the de Rham cohomology ring is generated by . Under Assumption 1.3, if and only if is a critical point of .
Proof.
Remark 3.20
The above theorem has a ‘wall-crossing invariance’ in the sense that it does not rely on the choice of . If is another algebra in which admits an homotopy equivalence such that . By Lemma 2.6, we have an isomorphism defined by as in (9), and the is exactly the superpotential associated to . Let . It follows from Corollary 3.16 that is a critical point of if and only if is a critical point of . Finally, by Proposition 3.13, if and only if .
4 Reduced Hochschild cohomology
4.1 Quantum cohomology: Review
4.1.1 Preparation
We will adopt the virtual language in [FOOO20], but the readers may also adopt their own conventions. By a smooth correspondence, we mean a tuple consisting of a compact metrizable space equipped with a Kuranishi structure, two smooth manifolds and , a strongly smooth map and a weakly submersive strongly smooth map . We have a correspondence map of degree between the space of differential forms:
(29) |
One can define the fiber product of two Kuranishi spaces and , and the composition formula [FOOO20, Theorem 10.21] implies
(30) |
On the other hand, a smooth correspondence induces a boundary smooth correspondence . The Stokes’ formulas in the Kuranishi theory [FOOO20, Theorem 9.28] is
(31) |
4.1.2 Definition
We briefly recall the basic aspects of the (small) quantum cohomology. A standard reference is [MS12]. Let be a formal symbol, and we define (c.f. [McL20])
(32) |
We may also replace by the image of the Hurewicz map . We call the quantum Novikov ring of , since we reserve the term ‘Novikov ring’ for the . Define
(33) |
Take the moduli space of genus-0 stable maps of homology class with marked points. Let
be the evaluation maps at the marked points. The quantum product of is defined as follows. First, in the chain level, we define for :
and define
Since the moduli has no codimension-one boundary, it follows from the Stokes’ formula (31) that the above assignment is a cochain map and hence induces a product map . Extending by linearity, we get the quantum product:
Abusing the notations, over the Novikov field , we also put
By the same discussion, it defines a quantum product
The Novikov field is algebraically closed [FOOO10a, Appendix A], so we will work with the latter to study the eigenvalues. But, the first is slightly more general and is still useful for our purpose. In either cases, it is standard that the product gives a ring structure. The leading term of is just the standard wedge (cup) product. Besides, the constant-one function is the unit in the quantum cohomology ring [MS12, Proposition 11.1.11].
4.1.3 An example:
Let be the standard generator represented by the line . The cohomology is a truncated polynomial ring generated by the class such that and . It suffices to compute for . When , it corresponds to the usual cup product. When , it is standard that (see e.g. [MS12, Example 11.1.12])
To sum up,
Namely, the quantum product on (resp. ) is given by
Recall that the first Chern class is . To study the eigenvalues of , it would be better to work with instead of . The matrix of is then given by
where denotes the identity matrix. So, the eigenvalues of solve the equation . Since , we finally know the eigenvalues of are
4.2 Reduced Hochschild cohomology
4.2.1 Label grading
Fix a -gapped algebra . We study the Hochschild cohomologies in our labeled setting §2.1.1. The is a subspace of the direct product where each is just a copy of with an extra label . Note that every naturally embeds into . Since involves , the operator system in only has a well-defined degree modulo 2. To settle this, we introduce the following degree on .
Definition 4.1.
The label degree of a -multilinear map in is defined to be
where is the shifted degree as a multilinear map (see §2.1.2). This is called the label grading.
Since , (). But, if is a gapped algebra on , then , , and so is homogeneous. For a -gapped homomorphism , one can similarly check .
4.2.2 Brace operations
The brace operation for is defined by Gerstenhaber [Ger63], and the higher braces are defined by Kadeishvili [Kad] and Getzler [Get93]. We can adapt the definitions to our labeled setting. Given homogeneously-graded , we define an element in by the formula:
|
where we denote for (so ). Moreover, note that the gappedness conditions (b) (c) in §2.1.1 ensure the above sum is finite, but the condition (a) is not necessary and will be omitted in §4.2.4. The brace operation has degree zero for the label grading in the sense that for homogeneously-graded elements, we have
(34) |
Recall that we already adopt the brace operations to denote the Gerstenhaber product in §2.1.2. Also, we adopt the convention that
By routine calculation, we can show that: (see [GJ94, Page 51] and [TT05, Proposition 2.3.2])
Proposition 4.2.
The brace operations satisfy the following property:
where the summation is over and .
The sign can be described briefly as follows: for each , we gather all ’s that appear to the left of , then compute the sum of the degrees of these ’s multiplied by the degree of . A few special cases of Proposition 4.2 are as follows:
where we also recall the convention that .
On the other hand, we define the Gerstenhaber bracket in our labeled setting as follows:
(35) |
Due to (34), . One can easily check the graded skew-symmetry: . A tedious but straightforward computation yields the graded Jacobi identity:
(36) |
4.2.3 Hochschild cohomology as usual
Given a gapped algebra , we define
(37) |
Clearly, , and it is called a Hochschild differential; thereafter, we may call an operator system in a Hochschild cochain. Since , we have , i.e. . In contrast, is only defined in ; this is also a reason why we introduce the label grading above. In addition, one can use (36) to show the graded Leibniz rule:
(38) |
In summary, is a differential graded Lie algebra. Now, the Hochschild cohomology of a gapped algebra is defined by
Next, we define the following Yoneda product on the cochain complex : (c.f. [Gan13])
(39) |
Then, we can carry out a few computations using Proposition 4.2:
Hence, a direct calculation yields that , and we get a well-defined Yoneda cup product on the Hochschild cohomology:
From (34) it follows that the label degree is , namely, .
Proposition 4.3.
The cup product defines a ring structure on the Hochschild cohomology .
Proof.
We aim to check the cup product is associative. In fact, by Proposition 4.2 again, we obtain
It follows that
Descending to the cohomology completes the proof. ∎
4.2.4 Reduced Hochschild cohomology
In practice, we need a slight variant. The space consists of those operator systems . By the gappedness condition (a) in §2.1.1, we have to assume . But, we must allow nontrivial component for later. Thus, we define
(40) |
to be the space of the operator systems such that is contained in and
(41) |
We keep using the label grading on , and we further define the grading on by
(42) |
Remark 4.4
Algebraically, the above version is needed for the unital ring structures. Geometrically, this is also necessary, because the operator (for the moduli space of constant maps with one boundary and interior markings as in §4.3) should correspond to a term with label .
Lemma 4.5.
The brace operations can be defined on .
Proof.
In particular, we can define and on . By comparison, is not defined for , since there may be infinite extra terms in (6) from the . We introduce mainly for the sake of closed-open operators, whereas we must still use rather than to develop the homotopy theory of algebras for the category , e.g. the Whitehead theorem 2.2. Furthermore, the condition (41) does not exactly match the unitality of an algebra or that of an homomorphism . Indeed, we only have and in general. But, according to our trial-and-error, the condition (41) is indeed the correct one as suggested below:
Lemma 4.6.
Suppose . Then,
-
1.
the Hochschild differential still gives a differential map on ;
-
2.
the Yoneda cup product induces a map .
Proof.
We only know , but we recall that .
(1). Given , it suffices to show . By Lemma 4.5, we have . Thus, it suffices to check the condition (41) for . Specifically, fix and ; we aim to show
vanishes all the time. We check it by cases. Recall that we denote (5).
-
When , we can similarly compute the sign. Using the condition (41) of deduces that
Combining Lemma 4.5 and 4.6 with the proof of Proposition 4.3 yields the following valid definition:
Definition 4.7.
The reduced Hochschild cohomology for is defined by
Moreover, the cup product also gives rise to a ring structure on .
4.2.5 Unitality
A major advantage of the reduced Hochschild cohomology is the unitality:
Lemma 4.8.
Fix . Then, is a unital ring such that the unit is given by
(43) |
where and for any . Moreover, its label degree is .
Proof.
Clearly, . By (42), the degree of is . Fix . Using the unitality of implies Similarly, we can check . ∎
4.2.6 -module
From now on, we assume the label group is . The quantum Novikov ring in (32) acts on by for any . That is, the has a natural -module structure. Specifically, if is supported in a single component , the is simply the same multilinear map for a different label, supported in instead. This will not violate (41) or any gappedness conditions since . Notice that the label degree (§4.2.1) will be changed by
(44) |
since . Particularly, we always have .
Proposition 4.9.
The -action is compatible with the brace operation, namely, for .
Proof.
We only consider , and the others are similar. By linearity, we may assume and are supported in and respectively, and we may also assume and . Without the labels, we simply have . Then, one can easily check that , , and are the same multilinear map as above, supported in with the same label. The signs are also the same thanks to (44). ∎
Corollary 4.10.
.
Corollary 4.11.
The (reduced) Hochschild cohomology is a -module.
4.3 From quantum cohomology to reduced Hochschild cohomology
We study the moduli spaces of pseudo-holomorphic curves. Let be an oriented relatively-spin Lagrangian submanifold in a symplectic manifold . Let be an -tame almost complex structure. Given and , we denote by the moduli space of all equivalence classes of -holomorphic stable maps of genus-0 with one boundary component in such that and , are the interior and boundary marked points respectively. Moreover, the moduli space is simply not defined when for the sake of the stability. Note that with the notation in §2.3.1, we have
(45) |
The moduli space admits natural evaluation maps corresponding to the marked points:
where and . The codimension-one boundary of in the sense of Kuranishi structure and smooth correspondence (29) is given by the following union of the fiber products:
(46) |
where the union is taken over all the -shuffles of with , , , and . Here a -shuffle is a permutation of such that and .
Consider the smooth correspondence given by , , , , and . For and for and , we define
by (29). Alternatively, it may be also instructive to adopt the following notation:
If , then we exceptionally define for , , and .
Proposition 4.12.
The operators satisfy the following properties:
-
(i)
. The only if .
-
(ii)
For any permutation , we have
where .
-
(iii)
When , we have (§2.3.1).
-
(iv)
When and , we have except where is the inclusion.
-
(v)
Let be the constant-one function. Then, except .
-
(vi)
Given and ,
where and .
Sketch of proof.
Nothing is new here, and we only give rough explanations; see the various literature for more details: [ST16], [FOOO10b, Theorem 3.8.32], [FOOO16, §2.3], and [FOOO19, Chapter 17]. First, the items (i) (ii) (iii) should be clear. We explain (iv). If , the moduli spaces consist of constant maps into . Hence, , and the evaluation maps just become the projection maps or the projection maps pre-composed with the inclusion . Then, . Note that only if the fibers of has dimension zero, namely, . When , the only possibility is that . In this case, , and . Next, we can check the item (v) by studying the forgetful map of the marked point of 1 in a similar way, c.f. [Yua20, §6]. Eventually, we explain (vi). For the smooth correspondence as above, applying the Stokes’ formulas (31) to (46) implies that: . Now, as , the equation in (vi) then follows. ∎
For our purpose, we focus on the case , then the equation in (vi) becomes the following:
(47) |
Accordingly, we can define a linear map
(48) |
by setting . Here one can directly check that the condition (41) by Proposition 4.12 (v). Moreover, for the label grading (§4.2.1), the item (i) implies
(49) |
By §4.2.6, we can extend it linearly and thus obtain a -linear map , still denoted by . Then, the equation (47) exactly implies
Consequently, the induces a -linear map to the reduced Hochschild cohomology of :
(50) |
Recall that the ud-homotopy theory of algebras for must work on in (4). In contrast, as can be nonzero by Proposition 4.12 (iv), we must work on in (40) here.
The reduced Hochschild cohomology ring (Definition 4.7) admits a unital ring structure. The unit is the that is supported in (Lemma 4.8), and its label degree is . Meanwhile, has a unital ring structure with the unit of degree .
Our goal is to show the gives a unital ring homomorphism. But, as we mentioned in the introduction, the main complication is not Theorem 4.13 below but that the moduli space geometry cannot make a ring homomorphism into the reduced Hochschild cohomology of the minimal model algebras. We will resolve this issue soon later by using several techniques about .
Theorem 4.13.
The map is a unital ring homomorphism of degree such that .
Sketch of proof.
The argument here is standard and well-known to many experts, and we simply rewrite it in our notations and languages. But, we will moreover discover that our notion of the reduced Hochschild cohomology fits perfectly as well. In short, Proposition 4.12 (v) corresponds to (41).
First off, the degree matches by (49). Next, we consider the forgetful map which forgets the maps and all the incoming boundary marked points and then shrinks the resulting unstable domain components if any. Given , we denote the fiber of over by
Notice that the is homeomorphic to the closed unit disk and has a stratification (see [FOOO16, Figure 2.6.1]) which consists of two copies of , , and three distinguished moduli points , , . Geometrically, we may assume one interior marking is at , and the other is denoted by . Then, the three moduli points corresponding to the situations when respectively. To be specific, we have the following fiber products:
(51) |
Now, we take a path from to and define
Its codimensional-one boundary is given by the union of , , and
(52) |

Given and , we define
by (29). Applying the Stokes’ formula (31) yields that
In reality, the left side together with those terms with in the first sum of the right side corresponds to the left side of the Stokes’ formula (31); all others correspond to the right side of (31): the first and second summations correspond to (52), and the third and forth summations correspond to (51). As in (48), we define a map
by setting . By Proposition 4.12 (v), the image of satisfies the condition (41) for . Now, the above relation can be concisely written as follows:
Accordingly, the map in (50) satisfies that for , we have
Ultimately, it remains to show the unitality. Let be the constant and be given in (43). Then, we aim to show . In fact, suppose is nonzero. If , then using Proposition 4.12 (iv) implies that and . If , it is defined by the moduli space . We consider the forgetful map . To produce a nonzero term, the dimension of the fiber of needs to be zero just as what we discussed before. But this is impossible when . See also [Fuk10]. ∎
5 Closed-open maps with quantum corrections
5.1 The maps and
Recall that the moduli space system of -holomorphic disks bounding gives rise to a chain-level algebra . A metric induces the so-called harmonic contraction for which applying the homological perturbation to yields the minimal model algebra along with an homotopy equivalence (see §2.3.1)
For simplicity, we set , , and . Note that they are contained in . The Whitehead theorem can be generalized to ; namely, there is a ud-homotopy inverse of in the sense of Theorem 2.2. Concerning (40), we define the following map:
(53) |
We apologize for the lack of motivation, but it is truly just found out by trial-and-error. We may assume is homogeneously-graded, say . Then, we explicitly have
Briefly, this reads . One can check that is -linear (§4.2.6). Further, given , the image satisfies (41) and so lies in , since and are unital. The label degree is , i.e. . Moreover, for the in (43), we have
(54) |
as . (Here we slightly abuse the notation .)
As said in the introduction, it is generally incorrect that the would induce a ring homomorphism between the two reduced Hochschild cohomologies and , but it is not far from so. Heuristically, if we could pretend that , then the would induce an honest ring homomorphism. But, is only ud-homotopic to , especially when the nontrivial Maslov-0 disks are allowed. Shortly, the above says that the gap for producing an honest ring homomorphism can be controlled by the ud-homotopy relations in . Anyway, we start with some useful computations:
Lemma 5.1.
Given , we have
|
Given , we have
|
Proof.
(i) May assume is homogeneously-graded and . First, by Proposition 4.2, we obtain . Because is an homomorphism from to , we have . Moreover, using the fact that is an homomorphism, we have .
(ii) May assume and are homogeneously-graded and . By Proposition 4.2,
Applying on both sides, and using the equations of both and , we complete the proof. ∎
Finally, we define the length-zero projection map:
(55) |
One can check that is -linear in the sense that . For (43), we have
(56) |
5.2 From reduced Hochschild cohomology to self Floer cohomology
There is really no hope to cook up a unital ring homomorphism from to . Notwithstanding, the following result will be sufficient for our purpose:
Theorem 5.2.
The composite map induces a unital ring homomorphism
Proof.
(a).
(b). If are -closed, then
First, may assume is homogeneously-graded and . Concerning the first half of Lemma 5.1, we compute that equals to
Moreover, since , we know due to Lemma 2.4. Accordingly, those terms with or all vanish modulo . So, we have:
By the first half of Lemma 5.1, it remains to prove
Indeed, we first note that modulo . Besides, all of satisfy the condition (41) except and , so any term in the expansion of must vanish. This completes the proof of (a).
5.3 Closed-open maps with Maslov-0 disks
By Theorem 4.13 and Theorem 5.2, the composition of and :
is a unital ring homomorphism. Recall that we have defined two versions of quantum cohomologies and in (33). As is a -algebra, we can consider the -linear extension of the restriction of on , which gives a map:
(57) |
Proposition 5.3.
The is a unital -algebra homomorphism and .
Proof.
Denote the quantum products in and by and respectively for a moment to distinguish. Recall that and are -linear, and is -linear. So, by construction, is also -linear, that is, . Since is the -linear extension, we see that for any . Let , and write and , where , , and . Now, we have . Finally, . ∎
On the other hand, just like the Gromov-Witten theory, the operator also satisfies the divisor axiom for the interior marked points. Specifically, if is a closed 2-form supported in , then
(58) |
Denote by the first Chern class of . Note that there exists a cycle in with and is Poincare dual to [FOOO19, §23.3]. Together with Proposition 4.12 (iii), we obtain
(59) |
Proposition 5.4.
.
Proof.
First, we compute in the cochain level:
Since , the semipositive condition implies that whenever . By this observation and by (59), the term
is contained in . By the semipositive condition again, we may assume or . Hence, whenever it is nonzero, we may always assume and for other , in particular, . Then, using the associativity relation yields that
Notice that . Thus,
where the terms with are killed modulo . Beware that we abuse the notation 1 to represent the constant-one functions in both and . Finally, back to the calculation at the start, using the unitality of further deduces that and there. To conclude,
Passing to the cohomology, we get . The proof is now complete. ∎
Suppose can lift to a weak bounding cochain ; or equivalently, suppose the ideal vanishes at , i.e. . (Indeed, up to Fukaya’s trick, we may even allow to lie in a neighborhood of in .) By Lemma 3.11, we get a unital -algebra homomorphism . Accordingly, the composition
(60) |
is also a unital -algebra homomorphism. In particular,
(61) |
Moreover, by Proposition 5.4, we also have
(62) |
After all the above preparations, there is no further obstacle for the proof of our local result:
Theorem 5.5 (Theorem A).
Suppose the cohomology ring is generated by . Under Assumption 1.3, any critical value of is an eigenvalue of .
Proof.
Let be a critical point of in the sense of Definition 3.15. We aim to show is an eigenvalue of . Arguing by contradiction, suppose was invertible in . Then, there would exist with . Notice that by (61) and (62). Since is a unital -algebra homomorphism, we conclude that
Namely, we must have . But, due to Theorem 3.19, the being a critical point of implies that . This is a contradiction. ∎
5.4 Global result and the family Floer program
Lastly, we want to adapt Theorem 5.5 to the non-archimedean SYZ picture, showing Conjecture 1.1 for the analytic mirror Landau-Ginzburg model in Theorem 1.5. That is, we aim to show Theorem B.
5.4.1 General aspects
A brief review of Theorem 1.5 is as follows. First, using the moduli space of holomorphic disks and the homological perturbation, we obtain an algebra in for each Lagrangian torus fiber . Take a small rational polyhedron in near , and we can identify with a subset in via integral affine coordinates. Define the and for as in §2.2, but now the ideal vanishes under Assumption 1.3. Now, a local chart of is identified with a polyhedral affinoid domain for the fibration map in (3). From the rigid analytic geometry, we know can be recognized as the spectrum of maximal ideals of the following affinoid algebra contained in :
(63) |
Recall that consists of all those formal power series in which converge on . Using the reverse isoperimetric inequalities [GS14] and shrinking if necessary, we may require the maps to in (11). In particular, the lies in or equivalently converges on .
The affinoid space embeds into the mirror analytic space as a local chart. In reality, the transition maps among all these local charts are given by restricting the homomorphisms in (9) to some affinoid algebra like (63). Eventually, by [Yua20], the various local charts glue to the mirror rigid analytic space .
5.4.2 Proof of the global result
Now, we are ready to prove Theorem B. Let be a critical value of the mirror Landau-Ginzburg superpotential at a point in the mirror analytic space . In view of Corollary 3.16, we may choose a specific local chart of to present the critical point . Actually, since as a set, there is a Lagrangian fiber so that its dual fiber contains the point . Remark that one may also take any other adjacent Lagrangian fiber thanks to the Fukaya’s trick. Next, we find a nearby local chart which corresponds to an algebra associated to . As said before, choosing integral affine coordinates near , this local chart can be identified with a polyhedral affinoid domain , and the dual fiber is then identified with the central fiber . The critical point can be also viewed as a point in , say . Let be the local expression of in this local chart. Recall that the nonvanishing of does not rely on the local chart, and so does the critical value . Now, it follows from Theorem 5.5 that is an eigenvalue of . Ultimately, applying the same argument to all critical points of , we complete the proof of Theorem B.
Acknowledgment.
The author thanks Kenji Fukaya for his constant encouragement, and Ezra Getzler and Boris Tsygan for helpful comments on Hochschild cohomology. The author is also grateful to Mohammed Abouzaid, Denis Auroux, Andrew Hanlon, Mark McLean, Yuhan Sun, and Eric Zaslow for their interest and stimulating discussions. Special thanks to the anonymous referee for the meticulous review and invaluable suggestions.
References
- [Abo17] Mohammed Abouzaid. The family Floer functor is faithful. Journal of the European Mathematical Society, 19(7):2139–2217, 2017.
- [Abo21] Mohammed Abouzaid. Homological mirror symmetry without correction. Journal of the American Mathematical Society, 2021.
- [AFO+] Mohammed Abouzaid, Kenji Fukaya, Yong-Geun Oh, Hiroshi Ohta, and Kaoru Ono. Quantum cohomology and split generation in Lagrangian Floer theory (in preparation).
- [Aur07] Denis Auroux. Mirror symmetry and T-duality in the complement of an anticanonical divisor. Journal of Gökova Geometry Topology, 1:51–91, 2007.
- [Ber12] Vladimir G Berkovich. Spectral theory and analytic geometry over non-Archimedean fields. Number 33. American Mathematical Soc., 2012.
- [Bos14] Siegfried Bosch. Lectures on formal and rigid geometry, volume 2105. Springer, 2014.
- [CBMS10] Ricardo Castaño-Bernard, Diego Matessi, and Jake P Solomon. Symmetries of Lagrangian fibrations. Advances in mathematics, 225(3):1341–1386, 2010.
- [CO06] Cheol-Hyun Cho and Yong-Geun Oh. Floer cohomology and disc instantons of Lagrangian torus fibers in Fano toric manifolds. Asian Journal of Mathematics, 10(4):773–814, 2006.
- [FOOO09] Kenji Fukaya, Yong-Geun Oh, Hiroshi Ohta, and Kaoru Ono. Canonical models of filtered -algebras and Morse complexes. New perspectives and challenges in symplectic field theory, 49:201–227, 2009.
- [FOOO10a] Kenji Fukaya, Yong-Geun Oh, Hiroshi Ohta, and Kaoru Ono. Lagrangian Floer theory on compact toric manifolds, I. Duke Mathematical Journal, 151(1):23–175, 2010.
- [FOOO10b] Kenji Fukaya, Yong-Geun Oh, Hiroshi Ohta, and Kaoru Ono. Lagrangian intersection Floer theory: anomaly and obstruction, Part I, volume 1. American Mathematical Soc., 2010.
- [FOOO10c] Kenji Fukaya, Yong-Geun Oh, Hiroshi Ohta, and Kaoru Ono. Lagrangian intersection Floer theory: anomaly and obstruction, Part II, volume 2. American Mathematical Soc., 2010.
- [FOOO12] Kenji Fukaya, Yong-Geun Oh, Hiroshi Ohta, and Kaoru Ono. Toric degeneration and nondisplaceable Lagrangian tori in . International Mathematics Research Notices, 2012(13):2942–2993, 2012.
- [FOOO16] Kenji Fukaya, Yong-Geun Oh, Hiroshi Ohta, and Kaoru Ono. Lagrangian Floer Theory and Mirror Symmetry on Compact Toric Manifolds. Société Mathématique de France, 2016.
- [FOOO19] Kenji Fukaya, Yong-Geun Oh, Hiroshi Ohta, and Kaoru Ono. Spectral invariants with bulk, quasi-morphisms and Lagrangian Floer theory, volume 260. American Mathematical Society, 2019.
- [FOOO20] Kenji Fukaya, Yong-Geun Oh, Hiroshi Ohta, and Kaoru Ono. Kuranishi Structures and Virtual Fundamental Chains. Springer, 2020.
- [Fuk09] Kenji Fukaya. Lagrangian surgery and rigid analytic family of Floer homologies. https://www.math.kyoto-u.ac.jp/ fukaya/Berkeley.pdf, 2009.
- [Fuk10] Kenji Fukaya. Cyclic symmetry and adic convergence in Lagrangian Floer theory. Kyoto Journal of Mathematics, 50(3):521–590, 2010.
- [Fuk11] Kenji Fukaya. Counting pseudo-holomorphic discs in Calabi-Yau 3-folds. Tohoku Mathematical Journal, Second Series, 63(4):697–727, 2011.
- [Gan13] Sheel Ganatra. Symplectic cohomology and duality for the wrapped fukaya category. arXiv preprint arXiv:1304.7312, 2013.
- [Ger63] Murray Gerstenhaber. The cohomology structure of an associative ring. Annals of Mathematics, pages 267–288, 1963.
- [Get93] Ezra Getzler. Cartan homotopy formulas and the gauss-manin connection in cyclic homology. In Israel Math. Conf. Proc, volume 7, pages 65–78, 1993.
- [GHK13] Mark Gross, Paul Hacking, and Sean Keel. Birational geometry of cluster algebras. arXiv preprint arXiv:1309.2573, 2013.
- [GHK15] Mark Gross, Paul Hacking, and Sean Keel. Mirror symmetry for log Calabi-Yau surfaces I. Publications Mathématiques de l’IHES, 122(1):65–168, 2015.
- [GHKK18] Mark Gross, Paul Hacking, Sean Keel, and Maxim Kontsevich. Canonical bases for cluster algebras. Journal of the American Mathematical Society, 31(2):497–608, 2018.
- [GJ94] Ezra Getzler and John DS Jones. Operads, homotopy algebra and iterated integrals for double loop spaces. arXiv preprint hep-th/9403055, 1994.
- [GS11] Mark Gross and Bernd Siebert. From real affine geometry to complex geometry. Annals of mathematics, pages 1301–1428, 2011.
- [GS14] Yoel Groman and Jake P Solomon. A reverse isoperimetric inequality for J-holomorphic curves. Geometric and Functional Analysis, 24(5):1448–1515, 2014.
- [HK20] Paul Hacking and Ailsa Keating. Homological mirror symmetry for log calabi-yau surfaces. arXiv preprint arXiv:2005.05010, 2020.
- [Kad] T Kadeishvili. Structure of -algebra and Hochschild and Harrison cohomology. arXiv preprint math/0210331.
- [Kon] Maxim Kontsevich. Bridgeland Stability over Non-Archimedean Fields. IHES website.
- [Kon95] Maxim Kontsevich. Homological algebra of mirror symmetry. In Proceedings of the international congress of mathematicians, pages 120–139. Springer, 1995.
- [McL20] Mark McLean. Birational Calabi-Yau manifolds have the same small quantum products. Annals of Mathematics, 191(2):439–579, 2020.
- [MS12] Dusa McDuff and Dietmar Salamon. J-holomorphic curves and symplectic topology, volume 52. American Mathematical Soc., 2012.
- [RS17] Alexander F Ritter and Ivan Smith. The monotone wrapped Fukaya category and the open-closed string map. Selecta Mathematica, 23(1):533–642, 2017.
- [Sei06] Paul Seidel. A biased view of symplectic cohomology. Current developments in mathematics, 2006(1):211–254, 2006.
- [She15] Nick Sheridan. Homological mirror symmetry for Calabi–Yau hypersurfaces in projective space. Inventiones mathematicae, 199(1):1–186, 2015.
- [She16] Nick Sheridan. On the Fukaya category of a Fano hypersurface in projective space. Publications mathématiques de l’IHÉS, 124(1):165–317, 2016.
- [Smi17] Ivan Smith. Stability conditions in symplectic topology. arXiv preprint arXiv:1711.04263, 2017.
- [Sol20] Jake P Solomon. Involutions, obstructions and mirror symmetry. Advances in Mathematics, 367:107107, 2020.
- [ST16] Jake P Solomon and Sara B Tukachinsky. Differential forms, Fukaya algebras, and Gromov-Witten axioms. arXiv preprint arXiv:1608.01304, 2016.
- [SYZ96] A Strominger, S-T Yau, and E Zaslow. Mirror symmetry is T-duality. Nuclear Physics. B, 479(1-2):243–259, 1996.
- [TT05] Dmitry Tamarkin and Boris Tsygan. The ring of differential operators on forms in noncommutative calculus. In Proceedings of Symposia in Pure Mathematics, volume 73. Citeseer, 2005.
- [Tu14] Junwu Tu. On the reconstruction problem in mirror symmetry. Advances in Mathematics, 256:449–478, 2014.
- [Yua] Hang Yuan. Fukaya category over affinoid coefficients. in preparation.
- [Yua20] Hang Yuan. Family Floer program and non-archimedean SYZ mirror construction. arXiv preprint arXiv: 2003.06106, 2020.
- [Yua22a] Hang Yuan. Family Floer mirror space for local SYZ singularities. arXiv preprint arXiv:2206.04652, 2022.
- [Yua22b] Hang Yuan. Family Floer SYZ singularities for the conifold transition. arXiv preprint arXiv:2212.13948, 2022.
- [Yua23] Hang Yuan. Family Floer SYZ conjecture for singularity. arXiv preprint arXiv:2305.13554, 2023.
- [Yua24] Hang Yuan. Non-archimedean analytic continuation of unobstructedness. arXiv preprint arXiv:2401.02577, 2024.