This paper was converted on www.awesomepapers.org from LaTeX by an anonymous user.
Want to know more? Visit the Converter page.

institutetext: Physical Sciences, Kingsborough Community College, The City University of New York,
2001 Oriental Boulevard, Brooklyn, NY 11235-2398, USA

R-symmetries and curvature constraints in A-twisted heterotic Landau-Ginzburg models

Richard S. Garavuso [email protected]
Abstract

In this paper, we discuss various aspects of a class of A-twisted heterotic Landau-Ginzburg models on a Kähler variety XX. We provide a classification of the R-symmetries in these models which allow the A-twist to be implemented, focusing on the case in which the gauge bundle is either a deformation of the tangent bundle of XX or a deformation of a sub-bundle of the tangent bundle of XX. Some anomaly-free examples are provided. The curvature constraint imposed by supersymmetry in these models when the superpotential is not holomorphic is reviewed. Constraints of this nature have been used to establish properties of analogues of pullbacks of Mathai-Quillen forms which arise in the correlation functions of the corresponding A-twisted or B-twisted heterotic Landau-Ginzburg models. The analogue most relevant to this paper is a deformation of the pullback of a Mathai-Quillen form. We discuss how this deformation may arise in the class of models studied in this paper. We then comment on how analogues of pullbacks of Mathai-Quillen forms not discussed in previous work may be obtained. Standard Mathai-Quillen formalism is reviewed in an appendix. We also include an appendix which discusses the deformation of the pullback of a Mathai-Quillen form.

1 Introduction

A Landau-Ginzburg model is a nonlinear sigma model with a superpotential. For a heterotic Landau-Ginzburg model Witten:Phases ; DistlerKachru:0-2-Landau-Ginzburg ; AdamsBasuSethi:0-2-Duality ; MelnikovSethi:Half-twisted ; GuffinSharpe:A-twistedheterotic ; MelnikovSethiSharpe:Recent-Developments ; GaravusoSharpe:Analogues , the nonlinear sigma model possesses only (0,2)(0,2) supersymmetry and the superpotential is a Grassmann-odd function of the superfields which may or may not be holomorphic.

Heterotic Landau-Ginzburg models have field content consisting of (0,2)(0,2) bosonic chiral superfields

Φi=(ϕi,ψ+i)\Phi^{i}=(\phi^{i},\psi^{i}_{+})

and (0,2)(0,2) fermionic chiral superfields

Λa=(λa,Ha,Ea),\Lambda^{a}=\left(\lambda^{a}_{-},H^{a},E^{a}\right),

along with their conjugate antichiral superfields

Φı¯=(ϕı¯,ψ+ı¯)\Phi^{\overline{\imath}}=\left(\phi^{\overline{\imath}},\psi^{\overline{\imath}}_{+}\right)

and

Λa¯=(λa¯,H¯a¯,E¯a¯).\Lambda^{\overline{a}}=\left(\lambda^{\overline{a}}_{-},\overline{H}^{\overline{a}},\overline{E}^{\overline{a}}\right).

The ϕi\phi^{i} are local complex coordinates on a Kähler variety XX. The EaE^{a} are local smooth sections of a Hermitian vector bundle \mathcal{E} over XX, i.e. EaΓ(X,)E^{a}\in\Gamma(X,\mathcal{E}). The HaH^{a} are nonpropagating auxiliary fields. The fermions couple to bundles as follows:

ψ+iΓ(KΣ1/2Φ(T1,0X)),\displaystyle\psi^{i}_{+}\in\Gamma\left(K^{1/2}_{\Sigma}\otimes\Phi^{*}\!\left(T^{1,0}X\right)\right), λaΓ(K¯Σ1/2(Φ¯)),\displaystyle\lambda^{a}_{-}\in\Gamma\left(\overline{K}^{1/2}_{\Sigma}\otimes\left(\Phi^{*}\overline{\mathcal{E}}\right)^{\vee}\right),
ψ+ı¯Γ(KΣ1/2(Φ(T1,0X))),\displaystyle\psi^{\overline{\imath}}_{+}\in\Gamma\left(K^{1/2}_{\Sigma}\otimes\left(\Phi^{*}\!\left(T^{1,0}X\right)\right)^{\vee}\right), λa¯Γ(K¯Σ1/2Φ¯),\displaystyle\lambda^{\overline{a}}_{-}\in\Gamma\left(\overline{K}^{1/2}_{\Sigma}\otimes\Phi^{*}\overline{\mathcal{E}}\right),

where Φ:ΣX\Phi:\Sigma\rightarrow X and KΣK_{\Sigma} is the canonical bundle on the worldsheet Σ\Sigma.

In GuffinSharpe:A-twistedheterotic , heterotic Landau-Ginzburg models with superpotential of the form

W=ΛaFa,W=\Lambda^{a}\,F_{a}\,, (1.1)

where FaΓ(X,)F_{a}\in\Gamma\left(X,\mathcal{E}^{\vee}\right) were considered. It was claimed in GaravusoSharpe:Analogues that, when the superpotential (1.1) is not holomorphic, supersymmetry imposes a constraint which relates the nonholomorphic parameters of the superpotential to the Hermitian curvature. The details supporting that claim were worked out in Garavuso:Curvature ; Garavuso:Nonholomorphic for the case Ea0E^{a}\equiv 0. This curvature constraint has been used in GaravusoSharpe:Analogues to establish properties of analogues of pullbacks of Mathai-Quillen forms. These analogues arise in the correlation functions of the corresponding A-twisted or B-twisted heterotic Landau-Ginzburg models.

In this paper, we will study certain aspects of A-twisted heterotic Landau-Ginzburg models with superpotential (1.1) and Ea0E^{a}\equiv 0. Such models yield the A-twisted (2,2)(2,2) Landau-Ginzburg models of GuffinSharpe:A-twisted when =TX\mathcal{E}=TX and ΛiFi=ΛiiW(2,2)\Lambda^{i}\,F_{i}=\Lambda^{i}\,\partial_{i}W^{(2,2)}, where W(2,2)W^{(2,2)} is the (2,2) superpotential. Although R-symmetries for (2,2) Landau-Ginzburg models have been classified, this has not been done for heterotic Landau-Ginzburg models. Furthermore, for (2,2) Landau-Ginzburg models, a classification has been given only for the case of holomorphic superpotentials KachruWitten:Computing . We will provide a classification of the R-symmetries which allow the A-twist to be implemented, focusing on the case in which \mathcal{E} is either a deformation of TXTX or a deformation of a sub-bundle of TXTX. The curvature constraint imposed by supersymmetry in these models when the superpotential is not holomorphic will be reviewed. The corresponding analogue of the pullback of a Mathai-Quillen form is a deformation of the pullback of a Mathai-Quillen form. We will discuss how this deformation may arise in the class of models studied in this paper. We will then comment on how analogues of pullbacks of Mathai-Quillen forms not discussed in previous work may be obtained.

This paper is organized as follows: The A-twist will be discussed in section 2. A classification of the corresponding R-symmetries, along with some anomaly-free examples, will be given in section 3. The curvature constraint imposed by supersymmetry when the superpotential is not holomorphic will be reviewed in section 4. In section 5, we will discuss how an analogue of a pullback of a Mathai-Quillen form may arise in the class of heterotic Landau-Ginzburg models discussed in this paper. In section 6, we will summarize our results and comment on how analogues of pullbacks of Mathai-Quillen forms not discussed in previous work may be obtained. Appendix A will review standard Mathai-Quillen formalism MathaiQuillen:Superconnections ; BerlinGetzlerVergne:Heat ; Kalkman:BRST ; Blau:The-Mathai-Quillen ; Wu:On-the-Mathai-Quillen ; CordesMooreRamgoolam:Lectures ; Wu:Mathai-Quillen . Finally, appendix B will discuss the analogue that is most relevant to this paper, i.e. a deformation of the pullback of a Mathai-Quillen form.

2 A-twist

Let XX be a Kähler variety with metric gg, antisymmetric tensor BB, local real coordinates ϕμ\phi^{\mu}, and local complex coordinates ϕi\phi^{i} with complex conjugates ϕı¯\phi^{\overline{\imath}}. Furthermore, let \mathcal{E} be a vector bundle over XX with Hermitian fiber metric hh. We consider the action GuffinSharpe:A-twistedheterotic of an A-twisted heterotic Landau-Ginzburg model on XX with gauge bundle \mathcal{E}:

S\displaystyle S =2tΣd2z[12(gμν+iBμν)zϕμz¯ϕν+igı¯iψ+ı¯D¯z¯ψ+i+ihaa¯λaDzλa¯\displaystyle=2t\int_{\Sigma}d^{2}z\left[\frac{1}{2}\left(g_{\mu\nu}+iB_{\mu\nu}\right)\partial_{z}\phi^{\mu}\partial_{\overline{z}}\phi^{\nu}+ig_{\overline{\imath}i}\psi_{+}^{\overline{\imath}}\overline{D}_{\overline{z}}\psi_{+}^{i}+ih_{a\overline{a}}\lambda_{-}^{a}D_{z}\lambda_{-}^{\overline{a}}\right.
+.Fiı¯aa¯ψ+iψ+ı¯λaλa¯+haa¯FaF¯a¯+ψ+iλaDiFa+ψ+ı¯λa¯D¯ı¯F¯a¯].\displaystyle\phantom{=2t\int_{\Sigma}d^{2}z\left[\right.}+\biggl{.}F_{i\overline{\imath}a\overline{a}}\,\psi_{+}^{i}\psi_{+}^{\overline{\imath}}\lambda_{-}^{a}\lambda_{-}^{\overline{a}}+h^{a\overline{a}}F_{a}\overline{F}_{\overline{a}}+\psi_{+}^{i}\lambda_{-}^{a}D_{i}F_{a}+\psi_{+}^{\overline{\imath}}\lambda_{-}^{\overline{a}}\overline{D}_{\overline{\imath}}\overline{F}_{\overline{a}}\biggr{]}. (2.1)

Here, tt is a coupling constant, Σ\Sigma is a Riemann surface, d2z=idzdz¯d^{2}z=-i\,dz\wedge d{\overline{z}}, FaΓ(X,)F_{a}\in\Gamma\left(X,\mathcal{E}^{\vee}\right), and

D¯z¯ψ+i\displaystyle\overline{D}_{\overline{z}}\,\psi^{i}_{+} =¯z¯ψ+i+¯z¯ϕjΓjkiψ+k,\displaystyle=\overline{\partial}_{\overline{z}}\,\psi_{+}^{i}+\overline{\partial}_{\overline{z}}\,\phi^{j}\,\Gamma^{i}_{jk}\psi^{k}_{+}\,, Dzλa¯\displaystyle D_{z}\lambda^{\overline{a}}_{-} =zλa¯+zϕı¯Aı¯b¯a¯λb¯,\displaystyle=\partial_{z}\lambda_{-}^{\overline{a}}+\partial_{z}\phi^{\overline{\imath}}A^{\overline{a}}_{\overline{\imath}\overline{b}}\,\lambda^{\overline{b}}_{-}\,,
DiFa\displaystyle D_{i}F_{a} =iFaAiabFb,\displaystyle=\partial_{i}F_{a}-A^{b}_{ia}F_{b}\,, D¯ı¯F¯a¯\displaystyle\overline{D}_{\overline{\imath}}\overline{F}_{\overline{a}} =¯ı¯F¯a¯Aı¯a¯b¯F¯b¯,\displaystyle=\overline{\partial}_{\overline{\imath}}\,\overline{F}_{\overline{a}}-A^{\overline{b}}_{\overline{\imath}\,\overline{a}}\,\overline{F}_{\overline{b}}\,,
Aiab\displaystyle A^{b}_{ia} =hbb¯hb¯a,i,\displaystyle=h^{b\overline{b}}\,h_{\overline{b}a,i}\,, Aı¯a¯b¯\displaystyle A^{\overline{b}}_{\overline{\imath}\,\overline{a}} =hb¯bhba¯,ı¯,\displaystyle=h^{\overline{b}b}\,h_{b\overline{a},\overline{\imath}}\,,
Γjki\displaystyle\Gamma^{i}_{jk} =giı¯gı¯k,j,\displaystyle=g^{i\overline{\imath}}\,g_{\overline{\imath}k,j}\,, Fiı¯aa¯\displaystyle F_{i\overline{\imath}a\overline{a}} =hab¯Aı¯a¯,ib¯.\displaystyle=h_{a\overline{b}}\,A^{\overline{b}}_{\overline{\imath}\,\overline{a},i}\,.

The A-twist is defined by choosing the fermions couple to bundles as follows:

ψ+iΓ(Φ(T1,0X)),\displaystyle\psi^{i}_{+}\in\Gamma\left(\Phi^{*}\!\left(T^{1,0}X\right)\right), λaΓ(K¯Σ(Φ¯)),\displaystyle\lambda^{a}_{-}\in\Gamma\left(\overline{K}_{\Sigma}\otimes\left(\Phi^{*}\overline{\mathcal{E}}\right)^{\vee}\right),
ψ+ı¯Γ(KΣ(Φ(T1,0X))),\displaystyle\psi^{\overline{\imath}}_{+}\in\Gamma\left(K_{\Sigma}\otimes\left(\Phi^{*}\!\left(T^{1,0}X\right)\right)^{\vee}\right), λa¯Γ(Φ¯),\displaystyle\lambda^{\overline{a}}_{-}\in\Gamma\left(\Phi^{*}\overline{\mathcal{E}}\right),

where Φ:ΣX\Phi:\Sigma\rightarrow X and KΣK_{\Sigma} is the canonical bundle on Σ\Sigma. Anomaly cancellation requires GuffinSharpe:A-twistedheterotic ; KatzSharpe:Notes ; Sharpe:Notes

ΛtopKX,ch2()=ch2(TX).\Lambda^{\textrm{top}}\mathcal{E}^{\vee}\simeq K_{X}\,,\qquad\textrm{ch}_{2}\left(\mathcal{E}\right)=\textrm{ch}_{2}\left(TX\right). (2.2)

The action (2) is invariant on-shell under the supersymmetry transformations

δϕi\displaystyle\delta\phi^{i} =iαψ+i,\displaystyle=i\alpha_{-}\psi^{i}_{+}\,, (2.3)
δϕı¯\displaystyle\delta\phi^{\overline{\imath}} =0,\displaystyle=0\,,
δψ+i\displaystyle\delta\psi^{i}_{+} =0,\displaystyle=0\,,
δψ+ı¯\displaystyle\delta\psi^{\overline{\imath}}_{+} =αzϕı¯,\displaystyle=-\alpha_{-}\partial_{z}\phi^{\overline{\imath}}\,,
δλa\displaystyle\delta\lambda^{a}_{-} =iαψ+jAjbaλb+iαhaa¯F¯a¯,\displaystyle=-i\alpha_{-}\psi^{j}_{+}\,A^{a}_{jb}\,\lambda^{b}_{-}+i\alpha_{-}h^{a\overline{a}}\,\overline{F}_{\overline{a}}\,,
δλa¯\displaystyle\delta\lambda^{\overline{a}}_{-} =0\displaystyle=0

up to a total derivative. Since we have integrated out the auxiliary fields HaH^{a}, one may use the λa\lambda^{a}_{-} equation of motion

λa:ihaa¯Dzλa¯+Fiı¯aa¯ψ+iψ+ı¯λa¯ψ+iDiFa=0,\lambda^{a}_{-}:\quad ih_{a\overline{a}}D_{z}\lambda^{\overline{a}}_{-}+F_{i\overline{\imath}a\overline{a}}\,\psi^{i}_{+}\psi^{\overline{\imath}}_{+}\lambda^{\overline{a}}_{-}-\psi^{i}_{+}D_{i}F_{a}=0\,, (2.4)

to show Garavuso:Curvature that the action (2) can be written

S=itΣd2z{Q,V}+tΣΦ(K)+2tΣd2z(ψ+ı¯λa¯D¯ı¯F¯a¯ψ+iλaDaFa),S=it\int_{\Sigma}d^{2}z\,\left\{Q,V\right\}+t\int_{\Sigma}\Phi^{*}(K)+2t\int_{\Sigma}d^{2}z\left(\psi_{+}^{\overline{\imath}}\lambda_{-}^{\overline{a}}\overline{D}_{\overline{\imath}}\overline{F}_{\overline{a}}-\psi_{+}^{i}\lambda_{-}^{a}D_{a}F_{a}\right), (2.5)

where

{Q,ϕi}\displaystyle\left\{Q,\phi^{i}\right\} =ψ+i,\displaystyle=-\psi^{i}_{+}\,,\qquad {Q,ϕı¯}\displaystyle\left\{Q,\phi^{\overline{\imath}}\right\} =0,\displaystyle=0\,,
{Q,ψ+i}\displaystyle\left\{Q,\psi^{i}_{+}\right\} =0,\displaystyle=0\,,\qquad {Q,ψ+ı¯}\displaystyle\left\{Q,\psi^{\overline{\imath}}_{+}\right\} =izϕı¯,\displaystyle=-i\partial_{z}\phi^{\overline{\imath}}\,,
{Q,λa}\displaystyle\left\{Q,\lambda^{a}_{-}\right\} =ψ+jAjbaλbhaa¯F¯a¯,\displaystyle=\psi^{j}_{+}A^{a}_{jb}\lambda^{b}_{-}-h^{a\overline{a}}\,\overline{F}_{\overline{a}}\,,\qquad {Q,λa¯}\displaystyle\left\{Q,\lambda^{\overline{a}}_{-}\right\} =0\displaystyle=0

are the BRST transformations (δf=iα{Q,f}\delta f=-i\alpha_{-}\{Q,f\}, where ff is any field),

V=2(gı¯iψ+ı¯¯z¯ϕi+iλaFa),V=2\left(g_{\overline{\imath}i}\psi^{\overline{\imath}}_{+}\overline{\partial}_{\overline{z}}\phi^{i}+i\lambda^{a}_{-}F_{a}\right),

and

ΣΦ(K)=Σd2z(giı¯+iBiı¯)(zϕi¯z¯ϕı¯¯z¯ϕizϕı¯)\int_{\Sigma}\Phi^{*}(K)=\int_{\Sigma}d^{2}z\left(g_{i\overline{\imath}}+iB_{i\overline{\imath}}\right)\left(\partial_{z}\phi^{i}\,\overline{\partial}_{\overline{z}}\phi^{\overline{\imath}}-\overline{\partial}_{\overline{z}}\phi^{i}\partial_{z}\phi^{\overline{\imath}}\right)

is the integral over the worldsheet Σ\Sigma of the pullback to Σ\Sigma of the complexified Kähler form

K=i(giı¯+iBiı¯)dϕidϕı¯.K=-i\left(g_{i\overline{\imath}}+iB_{i\overline{\imath}}\right)d\phi^{i}\wedge d\phi^{\overline{\imath}}\,.

3 R-symmetries

Let us now discuss the R-symmetries which allow the A-twist described in section 2 to be obtained. A classification of these R-symmetries will be given in section 3.1. Some anomaly-free examples will be given in section 3.2.

3.1 Classification

For Fa0F_{a}\equiv 0, the twisting is achieved by tensoring the fields with

KΣQR/2K¯ΣQL/2,K^{-Q_{R}/2}_{\Sigma}\otimes\overline{K}^{\,Q_{L}/2}_{\Sigma}\,,

where the fields have charges QLQ_{L} and QRQ_{R}, given in table 3.1,

Field QLQ_{L} QRQ_{R}
ϕi\phi^{i} 0 0
ϕı¯\phi^{\overline{\imath}} 0 0
ψ+i\psi^{i}_{+} 0 1
ψ+ı¯\psi^{\overline{\imath}}_{+} 0 1-1
λa\lambda^{a}_{-} 1 0
λa¯\lambda^{\overline{a}}_{-} 1-1 0
Table 3.1: Charges when Fa0F_{a}\equiv 0.

under U(1)LU(1)_{L} and U(1)RU(1)_{R} R-symmetries, respectively. These R-symmetries defined by QLQ_{L} and QRQ_{R} are broken when Fa0F_{a}\not\equiv 0.

Let us consider an FaF_{a} of the form

Fa=aG+Ga.F_{a}=\partial_{a}G+G_{a}\,. (3.1)

Here, GG is quasihomogeneous and meromorphic, i.e.

G(λniϕi,λmı¯ϕı¯)=λdG(ϕi,ϕı¯),G\left(\lambda^{n_{i}}\phi^{i},\lambda^{m_{\overline{\imath}}}\phi^{\overline{\imath}}\right)=\lambda^{d}\,G\left(\phi^{i},\phi^{\overline{\imath}}\right), (3.2)

where λ𝐂×\lambda\in\mathbf{C}^{\times}, ni=mı¯n_{i}=-m_{\overline{\imath}} and dd are integers, and the deformation GaG_{a} is chosen to be

Ga=a[1dini(ϕi)dni]=(ϕa)dna1.G_{a}=\partial_{a}\left[\frac{1}{d}\sum_{i}n_{i}\left(\phi^{i}\right)^{\frac{d}{n_{i}}}\right]=\left(\phi^{a}\right)^{\frac{d}{n_{a}}-1}\,. (3.3)

For an FaF_{a} of this form, we can define new charges QL=QLQQ^{\prime}_{L}=Q_{L}-Q and QR=QRQQ^{\prime}_{R}=Q_{R}-Q, given in table 3.2,

Field QLQ_{L} QRQ_{R} QQ QL=QLQQ^{\prime}_{L}=Q_{L}-Q QR=QRQQ^{\prime}_{R}=Q_{R}-Q
ϕi\phi^{i} 0 0 αi\alpha_{i} αi-\alpha_{i} αi-\alpha_{i}
ϕı¯\phi^{\overline{\imath}} 0 0 αi-\alpha_{i} αi\alpha_{i} αi\alpha_{i}
ψ+i\psi^{i}_{+} 0 1 αi\alpha_{i} αi-\alpha_{i} 1αi1-\alpha_{i}
ψ+ı¯\psi^{\overline{\imath}}_{+} 0 1-1 αi-\alpha_{i} αi\alpha_{i} αi1\alpha_{i}-1
λa\lambda^{a}_{-} 1 0 αa\alpha_{a} 1αa1-\alpha_{a} αa-\alpha_{a}
λa¯\lambda^{\overline{a}}_{-} 1-1 0 αa-\alpha_{a} αa1\alpha_{a}-1 αa\alpha_{a}
DiD_{i} 0 0 αi-\alpha_{i} αi\alpha_{i} αi\alpha_{i}
D¯ı¯\overline{D}_{\overline{\imath}} 0 0 αi\alpha_{i} αi-\alpha_{i} αi-\alpha_{i}
a\partial_{a} 0 0 αa-\alpha_{a} αa\alpha_{a} αa\alpha_{a}
¯a¯\overline{\partial}_{\overline{a}} 0 0 αa\alpha_{a} αa-\alpha_{a} αa-\alpha_{a}
GG 0 0 11 1-1 1-1
G¯\overline{G} 0 0 1-1 11 11
GaG_{a} 0 0 1αa1-\alpha_{a} αa1\alpha_{a}-1 αa1\alpha_{a}-1
G¯a¯\overline{G}_{\overline{a}} 0 0 αa1\alpha_{a}-1 1αa1-\alpha_{a} 1αa1-\alpha_{a}
Fa=aG+GaF_{a}=\partial_{a}G+G_{a} 0 0 1αa1-\alpha_{a} αa1\alpha_{a}-1 αa1\alpha_{a}-1
F¯a¯=¯a¯G¯+G¯a¯\overline{F}_{\overline{a}}=\overline{\partial}_{\overline{a}}\,\overline{G}+\overline{G}_{\overline{a}} 0 0 αa1\alpha_{a}-1 1αa1-\alpha_{a} 1αa1-\alpha_{a}
Table 3.2: Charges when Fa=aG+GaF_{a}=\partial_{a}G+G_{a}.

expressed in terms of the parameters

αi=ni/d=mı¯/d,αa=na/d=ma¯/d,\alpha_{i}=n_{i}/d=-m_{\overline{\imath}}/d\,,\qquad\alpha_{a}=n_{a}/d=-m_{\overline{a}}/d\,, (3.4)

which yield a U(1)L×U(1)RU(1)_{L}\times U(1)_{R}-invariant action. On the (2,2) locus, we have

QL(ϕi)\displaystyle Q^{\prime}_{L}\bigl{(}\phi^{i}\bigr{)} =QL(ψ+i),QL(λi)=QL(ϕi)+1,\displaystyle=Q^{\prime}_{L}\bigl{(}\psi^{i}_{+}\bigr{)},\quad Q^{\prime}_{L}\bigl{(}\lambda^{i}_{-}\bigr{)}=Q^{\prime}_{L}\bigl{(}\phi^{i}\bigr{)}+1\,,
QR(ϕi)\displaystyle Q^{\prime}_{R}\bigl{(}\phi^{i}\bigr{)} =QR(λi),QR(ψ+i)=QR(ϕi)+1.\displaystyle=Q^{\prime}_{R}\bigl{(}\lambda^{i}_{-}\bigr{)},\quad Q^{\prime}_{R}\bigl{(}\psi^{i}_{+}\bigr{)}=Q^{\prime}_{R}\bigl{(}\phi^{i}\bigr{)}+1\,.

Off of this locus, although one has a pair of U(1)U(1) symmetries, only U(1)RU(1)_{R} is an R-symmetry. The twisting is achieved by tensoring the fields with

KΣQR/2K¯ΣQL/2.K^{-Q^{\prime}_{R}/2}_{\Sigma}\otimes\overline{K}^{\,Q^{\prime}_{L}/2}_{\Sigma}\,.

Recall that for a Riemann surface Σ\Sigma of genus gg, the degree of the canonical bundle is 2g22g-2. It follows that, for the bundles KΣQR/2K^{-Q^{\prime}_{R}/2}_{\Sigma} and K¯ΣQL/2\overline{K}^{\,Q^{\prime}_{L}/2}_{\Sigma} to be well-defined, dd must divide g1g-1, i.e.

g=1+kd,k=0,1,2,.g=1+kd\,,\qquad k=0,1,2,\ldots\,. (3.5)

This genus issue is well understood; more details can be found in GuffinSharpe:A-twisted ; Witten:Algebraic ; Witten:The-N-matrix . Table 3.2 gives a classification of the R-symmetries in the models we are discussing in terms of the charges QLQ^{\prime}_{L} and QRQ^{\prime}_{R}.

3.2 Examples

Let us consider some examples in which \mathcal{E} is a deformation of TXTX. For such examples, the anomaly cancellation conditions (2.2) are satisfied.

As a first example, consider the case in which XX is a complex affine space and GG is a Fermat polynomial:

Example 3.1.

Let X=𝐂dX=\mathbf{C}^{d}, and

G=(ϕ1)d++(ϕd)d.G=\left(\phi^{1}\right)^{d}+\cdots+\left(\phi^{d}\right)^{d}\,.

Thus,

(n1,,nd)=(1,,1),\left(n_{1},\ldots,n_{d}\right)=\left(1,\ldots,1\right)\,,
Ga=(ϕa)d1,a=1,,d,G_{a}=\left(\phi^{a}\right)^{d-1}\,,\qquad a=1,\ldots,d\,,

and

αa=nad=1d,a=1,,d.\alpha_{a}=\frac{n_{a}}{d}=\frac{1}{d}\,,\qquad a=1,\ldots,d\,.

The twist described in this example can be defined on worldsheets of genus gg given by (3.5).

As a second example, consider the case in which XX is a complex projective space and GG is a Fermat polynomial with zero locus defining a hypersurface in XX:

Example 3.2.

Let X=𝐂𝐏d1X=\mathbf{CP}^{d-1}, and

G=(ϕ1)d++(ϕd)d.G=\left(\phi^{1}\right)^{d}+\cdots+\left(\phi^{d}\right)^{d}\,.

Thus,

{G=0}𝐂𝐏d1[d],\left\{G=0\right\}\in\mathbf{CP}^{d-1}[d]\,,
(n1,,nd)=(1,,1),\left(n_{1},\ldots,n_{d}\right)=\left(1,\ldots,1\right)\,,
Ga=(ϕa)d1,ϕaGa=0,a=1,,d,G_{a}=\left(\phi^{a}\right)^{d-1}\,,\qquad\phi^{a}\,G_{a}=0\,,\qquad a=1,\ldots,d\,,

and

αa=nad=1d,a=1,,d.\alpha_{a}=\frac{n_{a}}{d}=\frac{1}{d}\,,\qquad a=1,\ldots,d\,.

The twist described in this example can be defined on worldsheets of genus gg given by (3.5).

As a final example, consider the case in which XX is a weighted complex projective space and the zero locus of GG is a hypersurface in that space:

Example 3.3.

Let X=𝐖𝐂𝐏12,8,7,93X=\mathbf{WCP}^{3}_{12,8,7,9}, and

G=(ϕ1)3+ϕ1(ϕ2)3+ϕ2(ϕ2)4+(ϕ4)4.G=\left(\phi^{1}\right)^{3}+\phi^{1}\left(\phi^{2}\right)^{3}+\phi^{2}\left(\phi^{2}\right)^{4}+\left(\phi^{4}\right)^{4}\,.

Thus,

{G=0}𝐖𝐂𝐏n1,n2,n3,n43[d]=𝐖𝐂𝐏12,8,7,93[36],\left\{G=0\right\}\in\mathbf{WCP}^{3}_{n_{1},n_{2},n_{3},n_{4}}[d]=\mathbf{WCP}^{3}_{12,8,7,9}[36]\,,
Ga=(ϕa)dna1,ϕaGa=0,a=1,,4,G_{a}=\left(\phi^{a}\right)^{\frac{d}{n_{a}}-1}\,,\qquad\phi^{a}\,G_{a}=0\,,\qquad a=1,\ldots,4\,,

and

α1\displaystyle\alpha_{1} =n1d=1236=13,\displaystyle=\frac{n_{1}}{d}=\frac{12}{36}=\frac{1}{3}\,,
α2\displaystyle\alpha_{2} =n2d=836=29,\displaystyle=\frac{n_{2}}{d}=\frac{8}{36}=\frac{2}{9}\,,
α3\displaystyle\alpha_{3} =n3d=736,\displaystyle=\frac{n_{3}}{d}=\frac{7}{36}\,,
α4\displaystyle\alpha_{4} =n4d=936=14.\displaystyle=\frac{n_{4}}{d}=\frac{9}{36}=\frac{1}{4}\,.

The twist described in this example can be defined on worldsheets of genus gg given by (3.5):

g=1+kd\displaystyle g=1+kd =1+k(36),k=0,1,2,\displaystyle=1+k\left(36\right)\,,\qquad k=0,1,2,\ldots
=1,37,73,109,.\displaystyle=1,37,73,109,\ldots\,.

4 Curvature constraints

The action (2.5) is invariant on-shell under the supersymmetry transformations (2.3) up to a total derivative. It was claimed in GaravusoSharpe:Analogues that requiring this invariance when the superpotential (1.1) is not holomorphic imposes a constraint which relates the nonholomorphic parameters of the superpotential to the Hermitian curvature. This curvature constraint, along with an additional constraint imposed by supersymmetry, was derived in Garavuso:Curvature ; Garavuso:Nonholomorphic . Let us now briefly review the key steps of this derivation; see Garavuso:Curvature ; Garavuso:Nonholomorphic for more details.

Since δf=iα{Q,f}\delta f=-i\alpha_{-}\{Q,f\}, where ff is any field, the QQ-exact part of (2.5) is δ\delta-exact and hence δ\delta-closed. For the non-exact term of (2.5) involving Φ(K)\Phi^{*}(K), note that

ΣΦ(K)=Φ(Σ)K=Φ(Σ)[i(giı¯+iBiı¯)]𝑑ϕidϕı¯\int_{\Sigma}\Phi^{*}(K)=\int_{\Phi(\Sigma)}K=\int_{\Phi(\Sigma)}\left[-i\left(g_{i\overline{\imath}}+iB_{i\overline{\imath}}\right)\right]d\phi^{i}\wedge d\phi^{\overline{\imath}}

and KK satisfies

K=ik(giı¯+iBiı¯)dϕkdϕidϕı¯=0.\partial K=-i\,\partial_{k}\left(g_{i\overline{\imath}}+iB_{i\overline{\imath}}\right)d\phi^{k}\wedge d\phi^{i}\wedge d\phi^{\overline{\imath}}=0\,.

Thus,

δ[Φ(K)]=[Φ(K)]kδϕk=0.\delta\left[\Phi^{*}(K)\right]=\left[\Phi^{*}(K)\right]_{k}\delta\phi^{k}=0\,. (4.1)

It remains to consider the non-exact expression of (2.5) involving

ψ+ı¯λa¯D¯ı¯F¯a¯ψ+iλaDiFa.\psi_{+}^{\overline{\imath}}\lambda_{-}^{\overline{a}}\overline{D}_{\overline{\imath}}\overline{F}_{\overline{a}}-\psi_{+}^{i}\lambda_{-}^{a}D_{i}F_{a}\,.

First, we compute

δ(ψ+ı¯λa¯D¯ı¯F¯a¯)\displaystyle\delta\left(\psi^{\overline{\imath}}_{+}\lambda^{\overline{a}}_{-}\overline{D}_{\overline{\imath}}\overline{F}_{\overline{a}}\right) =(αzϕı¯)λa¯D¯ı¯F¯a¯ψ+ı¯λa¯Aı¯a¯,kb¯(iαψ+k)F¯b¯\displaystyle=\left(-\alpha_{-}\partial_{z}\phi^{\overline{\imath}}\right)\lambda^{\overline{a}}_{-}\,\overline{D}_{\overline{\imath}}\,\overline{F}_{\overline{a}}-\psi_{+}^{\overline{\imath}}\lambda_{-}^{\overline{a}}A^{\overline{b}}_{\overline{\imath}\,\overline{a},k}\left(i\alpha_{-}\psi^{k}_{+}\right)\overline{F}_{\overline{b}}
+ψ+ı¯λa¯(iD¯ı¯F¯a¯+Fiı¯aa¯hab¯F¯b¯)(iαψ+i).\displaystyle\phantom{=}+\psi^{\overline{\imath}}_{+}\lambda_{-}^{\overline{a}}\left(\partial_{i}\overline{D}_{\overline{\imath}}\overline{F}_{\overline{a}}+F_{i\overline{\imath}\,a\overline{a}}\,h^{a\overline{b}}\,\overline{F}_{\overline{b}}\right)\left(i\alpha_{-}\psi^{i}_{+}\right). (4.2)

Now, we compute

δ(ψ+iλaDiFa)\displaystyle\delta\left(-\psi^{i}_{+}\lambda^{a}_{-}D_{i}F_{a}\right) =αF¯a¯Dzλa¯+(iαhab¯F¯b¯)Fiı¯aa¯ψ+iψ+ı¯λa¯\displaystyle=-\,\alpha_{-}\overline{F}_{\overline{a}}\,D_{z}\lambda^{\overline{a}}_{-}+\left(i\alpha_{-}h^{a\overline{b}}\,\overline{F}_{\overline{b}}\right)F_{i\overline{\imath}a\overline{a}}\,\psi^{i}_{+}\psi^{\overline{\imath}}_{+}\lambda^{\overline{a}}_{-}
=(αzϕı¯)λa¯D¯ı¯F¯a¯αz(F¯a¯λa¯)+αF¯a¯,kzϕkλa¯\displaystyle=\left(\alpha_{-}\partial_{z}\phi^{\overline{\imath}}\right)\lambda^{\overline{a}}_{-}\,\overline{D}_{\overline{\imath}}\,\overline{F}_{\overline{a}}-\alpha_{-}\partial_{z}\!\left(\overline{F}_{\overline{a}}\,\lambda^{\overline{a}}_{-}\right)+\alpha_{-}\overline{F}_{\overline{a},k}\,\partial_{z}\phi^{k}\lambda^{\overline{a}}_{-}
+ψ+ı¯λa¯Aı¯a¯,kb¯(iαψ+k)F¯b¯,\displaystyle\phantom{=}+\psi^{\overline{\imath}}_{+}\lambda^{\overline{a}}_{-}\,A^{\overline{b}}_{\overline{\imath}\,\overline{a},k}\,\left(i\alpha_{-}\psi^{k}_{+}\right)\overline{F}_{\overline{b}}\,, (4.3)

where we have used the λa\lambda^{a}_{-} equation of motion (2.4) in the first step and Fiı¯aa¯=hab¯Aı¯a¯,ib¯F_{i\overline{\imath}a\overline{a}}=h_{a\overline{b}}\,A^{\overline{b}}_{\overline{\imath}\,\overline{a},i} in the last step. It follows that (4) cancels (4) up to a total derivative, i.e.

δ(ψ+iλaDiFa)=δ(ψ+ı¯λa¯D¯ı¯F¯a¯)αz(F¯a¯λa¯),\delta\left(-\psi^{i}_{+}\lambda^{a}_{-}D_{i}F_{a}\right)=-\,\delta\left(\psi^{\overline{\imath}}_{+}\lambda^{\overline{a}}_{-}\,\overline{D}_{\overline{\imath}}\overline{F}_{\overline{a}}\right)-\alpha_{-}\partial_{z}\!\left(\overline{F}_{\overline{a}}\,\lambda^{\overline{a}}_{-}\right), (4.4)

when both the curvature constraint

iD¯ı¯F¯a¯+Fiı¯aa¯hab¯F¯b¯=0\partial_{i}\overline{D}_{\overline{\imath}}\overline{F}_{\overline{a}}+F_{i\overline{\imath}\,a\overline{a}}\,h^{a\overline{b}}\,\overline{F}_{\overline{b}}=0 (4.5)

and the constraint

F¯a¯,kzϕkλa¯=0\overline{F}_{\overline{a},k}\,\partial_{z}\phi^{k}\lambda^{\overline{a}}_{-}=0 (4.6)

are satisfied.

Curvature constraints have been used in GaravusoSharpe:Analogues to establish properties of analogues of pullbacks of Mathai-Quillen forms. These analogues arise in the correlation functions of the corresponding A-twisted or B-twisted heterotic Landau-Ginzburg models. The analogue most relevant to this paper, i.e. a deformation of the pullback of a Mathai-Quillen form, is discussed in appendix B.

5 Physical realization of deformation of the pullback of a Mathai-Quillen form

Let us now describe how the deformation ωδs(𝒢,)\omega_{\delta s}(\mathcal{G},\nabla), given by (B.1), of the pullback su(𝒢,)s^{*}u(\mathcal{G},\nabla), given by (A.5), of a Mathai-Quillen form u(𝒢,)u(\mathcal{G},\nabla), given by (A.1), may arise in the class of A-twisted heterotic Landau-Ginzburg models discussed in this paper.

Mathematically, the tangent bundle to Y{s=0}Y\equiv\{s=0\}, s=(sp)s=(s_{p}), is defined by the kernel in the short exact sequence

0TYTM|Y(Disp)𝒢|Y 0.0\>\longrightarrow\>TY\>\longrightarrow\>TM|_{Y}\>\stackrel{{\scriptstyle(D_{i}s_{p})}}{{\longrightarrow}}\>{\cal G}|_{Y}\>\longrightarrow\>0.

A deformation of the tangent bundle above is defined by

0TM|Y(Disp+(δs)ip)𝒢|Y 0,0\>\longrightarrow\>{\mathcal{E}^{\prime}}\>\longrightarrow\>TM|_{Y}\>\stackrel{{\scriptstyle(D_{i}s_{p}+(\delta s)_{ip})}}{{\longrightarrow}}\>{\cal G}|_{Y}\>\longrightarrow\>0,

where the (δs)ip(\delta s)_{ip} define the deformation.

The action of the A-twisted heterotic Landau-Ginzburg model that RG flows to a nonlinear sigma model with tangent bundle deformation above is given by GuffinSharpe:A-twistedheterotic

S\displaystyle S =2tΣd2z[12(gμν+iBμν)zϕμ¯z¯ϕν+iga¯aψ+a¯D¯z¯ψ+a+igbb¯λbDzλb¯\displaystyle=2t\int_{\Sigma}d^{2}z\left[\frac{1}{2}\left(g_{\mu\nu}+iB_{\mu\nu}\right)\partial_{z}\phi^{\mu}\overline{\partial}_{\overline{z}}\phi^{\nu}+ig_{\overline{a}a}\psi^{\overline{a}}_{+}\overline{D}_{\overline{z}}\psi^{a}_{+}+ig_{b\overline{b}}\lambda^{b}_{-}D_{z}\lambda^{\overline{b}}_{-}\right.
.+Raa¯bb¯ψ+aψ+a¯λbλb¯+gaa¯FaF¯a¯+ψ+aλbDaFb+ψ+a¯λb¯D¯a¯F¯b¯],\displaystyle\phantom{=2t\int_{\Sigma}d^{2}z\left[\right.}\biggl{.}+R_{a\overline{a}b\overline{b}}\psi^{a}_{+}\psi^{\overline{a}}_{+}\lambda^{b}_{-}\lambda^{\overline{b}}_{-}+g^{a\overline{a}}F_{a}\overline{F}_{\overline{a}}+\psi^{a}_{+}\lambda^{b}_{-}D_{a}F_{b}+\psi^{\overline{a}}_{+}\lambda^{\overline{b}}_{-}\overline{D}_{\overline{a}}\overline{F}_{\overline{b}}\biggr{]}, (5.1)

with target space

X=Tot(𝒢πM)X\>=\>{\rm Tot}\left({\cal G}^{*}\>\stackrel{{\scriptstyle\pi}}{{\longrightarrow}}\>M\right)

and gauge bundle =TX{\cal E}=TX, where

Fa=(Fp,Fi)=(sp,ϕp(Disp+(δs)ip)),F¯a¯=(F¯p¯,F¯ı¯)=(s¯p¯,ϕp¯(D¯ı¯s¯p¯+(δs¯)ı¯p¯)),F_{a}=(F_{p},F_{i})=\left(s_{p},\phi^{p}(D_{i}s_{p}+(\delta s)_{ip})\right)\,,\qquad\overline{F}_{\overline{a}}=\left(\overline{F}_{\overline{p}},\overline{F}_{\overline{\imath}}\right)=\left(\overline{s}_{\overline{p}},\phi^{\overline{p}}\left(\overline{D}_{\overline{\imath}}\overline{s}_{\overline{p}}+(\delta\overline{s})_{\overline{\imath}\,\overline{p}}\right)\right)\,,
DaFb\displaystyle D_{a}F_{b} =aFbΓabcFc,\displaystyle=\partial_{a}F_{b}-\Gamma^{c}_{ab}F_{c}\,,\quad D¯a¯F¯b¯\displaystyle\overline{D}_{\overline{a}}\overline{F}_{\overline{b}} =¯a¯F¯b¯Γa¯b¯c¯F¯c¯,\displaystyle=\overline{\partial}_{\overline{a}}\overline{F}_{\overline{b}}-\Gamma^{\overline{c}}_{\overline{a}\overline{b}}\overline{F}_{\overline{c}}\,,
D¯z¯ψ+a\displaystyle\overline{D}_{\overline{z}}\psi^{a}_{+} =¯z¯ψ+a+¯z¯ϕbΓbcaψ+c,\displaystyle=\overline{\partial}_{\overline{z}}\psi^{a}_{+}+\overline{\partial}_{\overline{z}}\phi^{b}\Gamma^{a}_{bc}\psi^{c}_{+}\,,\quad Dzλb¯\displaystyle D_{z}\lambda^{\overline{b}}_{-} =zλb¯+zϕa¯Γa¯c¯b¯λc¯,\displaystyle=\partial_{z}\lambda^{\overline{b}}_{-}+\partial_{z}\phi^{\overline{a}}\Gamma^{\overline{b}}_{\overline{a}\,\overline{c}}\lambda^{\overline{c}}_{-}\,,

and

ψ+i\displaystyle\psi^{i}_{+} χi\displaystyle\equiv\chi^{i}\! \displaystyle\in Γ(Φ(T1,0M)),\displaystyle\Gamma\left(\Phi^{*}\!\left(T^{1,0}M\right)\right),\quad λi\displaystyle\lambda^{i}_{-} λz¯i\displaystyle\equiv\lambda^{i}_{\overline{z}}\! \displaystyle\in Γ(K¯Σ(Φ(T0,1M))),\displaystyle\Gamma\left(\overline{K}_{\Sigma}\otimes\left(\Phi^{*}\!\left(T^{0,1}M\right)\right)\!^{\vee}\right),
ψ+ı¯\displaystyle\psi^{\overline{\imath}}_{+} ψzı¯\displaystyle\equiv\psi^{\overline{\imath}}_{z}\! \displaystyle\in Γ(KΣ(Φ(T1,0M))),\displaystyle\Gamma\left(K_{\Sigma}\otimes\left(\Phi^{*}\!\left(T^{1,0}M\right)\right)\!^{\vee}\right),\quad λı¯\displaystyle\lambda^{\overline{\imath}}_{-} λı¯\displaystyle\equiv\lambda^{\overline{\imath}}\! \displaystyle\in Γ(Φ(T0,1M)),\displaystyle\Gamma\left(\Phi^{*}\!\left(T^{0,1}M\right)\right),
ψ+p\displaystyle\psi^{p}_{+} ψzp\displaystyle\equiv\psi^{p}_{z}\! \displaystyle\in Γ(KΣΦTπ1,0),\displaystyle\Gamma\left(K_{\Sigma}\otimes\Phi^{*}\,T^{1,0}_{\pi}\right),\quad λp\displaystyle\lambda^{p}_{-} λp\displaystyle\equiv\lambda^{p}\! \displaystyle\in Γ((ΦTπ0,1)),\displaystyle\Gamma\left(\left(\Phi^{*}\,T^{0,1}_{\pi}\right)\!^{\vee}\right),
ψ+p¯\displaystyle\psi^{\overline{p}}_{+} χp¯\displaystyle\equiv\chi^{\overline{p}}\! \displaystyle\in Γ((ΦTπ1,0)),\displaystyle\Gamma\left(\left(\Phi^{*}\,T^{1,0}_{\pi}\right)\!^{\vee}\right),\quad λp¯\displaystyle\lambda^{\overline{p}}_{-} λz¯p¯\displaystyle\equiv\lambda^{\overline{p}}_{\overline{z}}\! \displaystyle\in Γ(K¯ΣΦTπ0,1),\displaystyle\Gamma\left(\overline{K}_{\Sigma}\otimes\Phi^{*}\,T^{0,1}_{\pi}\right),
ϕp\displaystyle\phi^{p} pz\displaystyle\equiv p_{z}\! \displaystyle\in Γ(KΣΦTπ1,0),\displaystyle\Gamma\left(K_{\Sigma}\otimes\Phi^{*}\,T^{1,0}_{\pi}\right),\quad ϕp¯\displaystyle\phi^{\overline{p}} p¯z¯\displaystyle\equiv\overline{p}_{\overline{z}}\! \displaystyle\in Γ(K¯ΣΦTπ0,1).\displaystyle\Gamma\left(\overline{K}_{\Sigma}\otimes\Phi^{*}\,T^{0,1}_{\pi}\right).

If we restrict to zero modes on a genus zero worldsheet, in the degree zero sector we find the following interactions among zero modes:

gp¯p\displaystyle g^{\overline{p}p} F¯p¯Fp+χiλpDiFp+χp¯λı¯D¯p¯F¯ı¯+Rip¯pı¯χiχp¯λpλı¯\displaystyle\overline{F}_{\overline{p}}F_{p}+\chi^{i}\lambda^{p}D_{i}F_{p}+\chi^{\overline{p}}\lambda^{\overline{\imath}}\,\overline{D}_{\overline{p}}\overline{F}_{\overline{\imath}}+R_{i\overline{p}p\overline{\imath}}\chi^{i}\chi^{\overline{p}}\lambda^{p}\lambda^{\overline{\imath}}
=gp¯ps¯p¯sp+χiλpDisp+χp¯λı¯(D¯ı¯s¯p¯+(δs¯)ı¯p¯)+Rip¯pı¯χiχp¯λpλı¯.\displaystyle=g^{\overline{p}p}\overline{s}_{\overline{p}}s_{p}+\chi^{i}\lambda^{p}D_{i}s_{p}+\chi^{\overline{p}}\lambda^{\overline{\imath}}\left(\overline{D}_{\overline{\imath}}\overline{s}_{\overline{p}}+(\delta\overline{s})_{\overline{\imath}\overline{p}}\right)+R_{i\overline{p}p\overline{\imath}}\chi^{i}\chi^{\overline{p}}\lambda^{p}\lambda^{\overline{\imath}}\,.

If we now complex conjugate so as to relate the heterotic expression above to standard mathematics conventions, we find

gpp¯\displaystyle g^{p\overline{p}} sps¯p¯+χı¯λp¯D¯ı¯s¯p¯+χpλi(Disp+(δs)ip)+Rı¯pp¯iχı¯χpλp¯λi\displaystyle s_{p}\overline{s}_{\overline{p}}+\chi^{\overline{\imath}}\lambda^{\overline{p}}\,\overline{D}_{\overline{\imath}}\overline{s}_{\overline{p}}+\chi^{p}\lambda^{i}\left(D_{i}s_{p}+(\delta s)_{ip}\right)+R_{\overline{\imath}p\overline{p}i}\chi^{\overline{\imath}}\chi^{p}\lambda^{\overline{p}}\lambda^{i}
=gpp¯sps¯p¯+ρpDsp+D¯s¯p¯ρp¯+ρp¯p¯pρp+ρpdϕi(δs)ip\displaystyle=g^{p\overline{p}}s_{p}\overline{s}_{\overline{p}}+\rho^{p}Ds_{p}+\overline{D}\overline{s}_{\overline{p}}\,\rho^{\overline{p}}+\rho^{\overline{p}}\mathcal{R}_{\overline{p}p}\rho^{p}+\rho^{p}d\phi^{i}\,(\delta s)_{ip}
=(spep,s¯p¯ep¯)𝒢+ρpfp,Dspep𝒢+D¯s¯p¯ep¯,ρp¯fp¯𝒢\displaystyle=\left(s_{p}e^{p},\overline{s}_{\overline{p}}e^{\overline{p}}\right)_{\cal G}+\left\langle\rho^{p^{\prime}}f_{p^{\prime}},Ds_{p}e^{p}\right\rangle_{\cal G}+\left\langle\overline{D}\overline{s}_{\overline{p}}e^{\overline{p}},\rho^{\overline{p}^{\prime}}f_{\overline{p}^{\prime}}\right\rangle_{\cal G}
+(ρp¯fp¯,fp¯(p¯pfp,ρpfp)𝒢)𝒢+ρpfp,dϕi(δs)ipep𝒢\displaystyle\phantom{=}+\left(\rho^{\overline{p}^{\prime}}f_{\overline{p}^{\prime}},f^{\overline{p}}\left(\mathcal{R}_{\overline{p}p}f^{p},\rho^{p}f_{p}\right)_{{\cal G}^{\vee}}\right)_{{\cal G}^{\vee}}+\left\langle\rho^{p^{\prime}}f_{p^{\prime}},d\phi^{i}\,(\delta s)_{ip}e^{p}\right\rangle_{\cal G}
=𝒜+ρpfp,dϕi(δs)ipep𝒢\displaystyle={\cal A}+\left\langle\rho^{p^{\prime}}f_{p^{\prime}},d\phi^{i}\,(\delta s)_{ip}e^{p}\right\rangle_{\cal G}
=𝒜δs,\displaystyle={\cal A}_{\delta s}\,, (5.2)

which is minus the exponent of (B.1). The deformation ωδs(𝒢,)\omega_{\delta s}(\mathcal{G},\nabla) will appear in the corresponding correlation functions. Explicitly, from the discussion in appendix B, we see that

𝒪~1𝒪~kX𝒪~1𝒪~kωδs(𝒢,)=Y𝒪1𝒪k,\langle\widetilde{\mathcal{O}}_{1}\cdots\widetilde{\mathcal{O}}_{k}\rangle\propto\int_{X}\widetilde{\mathcal{O}}_{1}\wedge\cdots\wedge\widetilde{\mathcal{O}}_{k}\wedge\omega_{\delta s}(\mathcal{G},\nabla)=\int_{Y}\mathcal{O}_{1}\wedge\cdots\wedge\mathcal{O}_{k}\,, (5.3)

where

𝒪~1𝒪~kHdimMrk𝒢(M,rkTMrk𝒢𝒢)\widetilde{\mathcal{O}}_{1}\wedge\cdots\wedge\widetilde{\mathcal{O}}_{k}\in H^{\dim{M}-\textrm{rk}\,\mathcal{G}}\left(M,\wedge^{\textrm{rk}\,TM-\textrm{rk}\,\mathcal{G}}\mathcal{G}^{\vee}\right)

and 𝒪~H(M,(TM))\widetilde{\mathcal{O}}\in H^{\bullet}\left(M,\wedge^{\bullet}(TM)^{\vee}\right) is a lift of 𝒪H(Y,)\mathcal{O}\in H^{\bullet}\left(Y,\wedge^{\bullet}\mathcal{\mathcal{E}}^{\prime\vee}\right).

6 Summary and outlook

We have studied certain aspects of A-twisted heterotic Landau Ginzburg models on a Kähler variety XX with gauge bundle \mathcal{E}, superpotential (1.1)

W=ΛaFa,W=\Lambda^{a}F_{a}\,,

and Ea0E^{a}\equiv 0. Table 3.2 provides a classification of the R-symmetries which allow the A-twist to be implemented when \mathcal{E} is either a deformation of TXTX or a deformation of a sub-bundle of TXTX. Some anomaly-free examples were provided in section 3.2. When the superpotential is not holomorphic, supersymmetry imposes the curvature constraint (4.5)

iD¯ı¯F¯a¯+Fiı¯aa¯hab¯F¯b¯=0\partial_{i}\overline{D}_{\overline{\imath}}\overline{F}_{\overline{a}}+F_{i\overline{\imath}\,a\overline{a}}\,h^{a\overline{b}}\,\overline{F}_{\overline{b}}=0

and the constraint (4.6)

F¯a¯,kzϕkλa¯=0.\overline{F}_{\overline{a},k}\,\partial_{z}\phi^{k}\lambda^{\overline{a}}_{-}=0\,.

The curvature constraint (4.5) was used in GaravusoSharpe:Analogues to establish properties of the deformation ωδs(𝒢,)\omega_{\delta s}(\mathcal{G},\nabla), given by (B.1), of the pullback su(𝒢,)s^{*}u(\mathcal{G},\nabla), given by (A.5), of a Mathai-Quillen form u(𝒢,)u(\mathcal{G},\nabla), given by (A.1). In section 5, we described how ωδs(𝒢,)\omega_{\delta s}(\mathcal{G},\nabla) may arise in the class of heterotic Landau-Ginzburg models studied in this paper.

It would be interesting to consider A-twisted and B-twisted heterotic Landau-Ginzburg models with more general Grassmann-odd superpotentials. For example, one may consider the superpotential GuffinSharpe:A-twisted

W=ΛaΛbΛcFabc.W=\Lambda^{a}\Lambda^{b}\Lambda^{c}F_{abc}\,.

If this more general superpotential is not holomorphic, then supersymmetry should impose a curvature constraint analogous to (4.5) and a constraint analogous to (4.6). These new constraints could be derived using arguments similar to those used in Garavuso:Curvature ; Garavuso:Nonholomorphic . Furthermore, using arguments similar to those used in GaravusoSharpe:Analogues , the new curvature constraint could then be used to establish properties of new analogues of pullbacks of Mathai-Quillen forms which arise in the correlation functions of the corresponding A-twisted or B-twisted heterotic Landau-Ginzburg models. We leave a detailed study of this to future work.

Acknowledgements.
The author thanks Mauricio Romo for useful discussions.

Appendix A Review of Mathai-Quillen formalism

Consider an oriented vector bundle 𝒢𝜋M\mathcal{G}\overset{\pi}{\longrightarrow}M of real rank r=2mr=2m, with standard fiber VV, where MM is an oriented closed manifold of real dimension nrn\geq r. Suppose that 𝒢\mathcal{G} has Euclidean metric (,)𝒢(\cdot,\cdot)_{\mathcal{G}} and compatible connection \nabla. Under these circumstances, the Mathai-Quillen formalism MathaiQuillen:Superconnections ; BerlinGetzlerVergne:Heat ; Kalkman:BRST ; Blau:The-Mathai-Quillen ; Wu:On-the-Mathai-Quillen ; CordesMooreRamgoolam:Lectures ; Wu:Mathai-Quillen provides an explicit representative u(𝒢,)u(\mathcal{G},\nabla) of the Thom class of 𝒢\mathcal{G}. Furthermore, the pullback su(𝒢,)s^{*}u(\mathcal{G},\nabla) of u(𝒢,)u(\mathcal{G},\nabla) by any section s:M𝒢s:M\rightarrow\mathcal{G} of 𝒢\mathcal{G} is a representative of the Euler class of 𝒢\mathcal{G}. Let us review the formalism in more detail.

A.1 Conventions

Our conventions for MM, 𝒢\mathcal{G}, and the dual 𝒢\mathcal{G}^{\vee} of 𝒢\mathcal{G} are as follows. The exterior derivatives on MM and 𝒢\mathcal{G} are respectively denoted by dd and d𝒢d^{\mathcal{G}}. We choose local coordinates ϕI\phi^{I} on MM, where I=1,,nI=1,\ldots,n. The connection on 𝒢\mathcal{G} is then given by =dϕII\nabla=d\phi^{I}\nabla_{I}. In terms of this connection, the curvature 2-form on 𝒢\mathcal{G} is given by =2\mathcal{R}=\nabla^{2}. We choose a local oriented orthonormal frame {eA}\{e_{A}\} for 𝒢\mathcal{G} and let {fA}\{f^{A}\} be the dual coframe, where A=1,,rA=1,\ldots,r. The section ss may thus be expressed as s=sAeAs=s^{A}e_{A}. Similarly, we write ρ=ρAfA\rho=\rho_{A}f^{A}, where the ρA\rho_{A} are anticommuting orthonormal coordinates on 𝒢\mathcal{G}^{\vee}. The dual pairing on 𝒢\mathcal{G} is denoted by ,𝒢\langle\cdot,\cdot\rangle_{\mathcal{G}}. Finally, the metric on 𝒢\mathcal{G}^{\vee} is denoted by (,)𝒢(\cdot,\cdot)_{\mathcal{G}^{\vee}}.

Now, consider the pullback bundle π𝒢𝒢\pi^{*}\mathcal{G}\rightarrow\mathcal{G}, i.e. the bundle over 𝒢\mathcal{G} whose fiber at g𝒢g\in\mathcal{G} is (π𝒢)g=𝒢π(g)(\pi^{*}\mathcal{G})_{g}=\mathcal{G}_{\pi(g)}. This bundle has Euclidean metric π(,)𝒢(,)π𝒢\pi^{*}(\cdot,\cdot)_{\mathcal{G}}\equiv(\cdot,\cdot)_{\pi^{*}\mathcal{G}}, compatible connection π~\pi^{*}\nabla\equiv\widetilde{\nabla}, curvature 2-form π~\pi^{*}\mathcal{R}\equiv\widetilde{\mathcal{R}}, local oriented orthonormal frame {πeA}{e~A}\{\pi^{*}e_{A}\}\equiv\{\tilde{e}_{A}\}, and tautological section x~=x~Ae~A\tilde{x}=\tilde{x}^{A}\tilde{e}_{A}. (The tautological section of π𝒢𝒢\pi^{*}\mathcal{G}\rightarrow\mathcal{G} is the section which maps a point g𝒢g\in\mathcal{G} to (g,g)π𝒢(g,g)\in\pi^{*}\mathcal{G}.) The dual bundle (π𝒢)𝒢(\pi^{*}\mathcal{G})^{\vee}\rightarrow\mathcal{G} has coframe {(π)fA}{f~A}\{(\pi^{\vee})^{*}f^{A}\}\equiv\{\tilde{f}^{A}\} and metric (,)(π𝒢)(\cdot,\cdot)_{(\pi^{*}\mathcal{G})^{\vee}}. We write ρ~=ρ~Af~A\tilde{\rho}=\tilde{\rho}_{A}\tilde{f}^{A}, where the ρ~A(π)ρA\tilde{\rho}_{A}\equiv(\pi^{\vee})^{*}\rho_{A} are anticommuting orthonormal coordinates on (π𝒢)(\pi^{*}\mathcal{G})^{\vee}. The dual pairing on πE\pi^{*}E is denoted by ,π𝒢\langle\cdot,\cdot\rangle_{\pi^{*}\mathcal{G}}.

A.2 Mathai-Quillen Thom class representative

Consider the Mathai-Quillen form

u(𝒢,)=ar𝑑ρ~exp(𝒜~),u(\mathcal{G},\nabla)=a_{r}\int d\tilde{\rho}\,\exp\left(-\tilde{\mathcal{A}}\right), (A.1)

where

ar=(1)r(r+1)2(2π)r2a_{r}=\frac{(-1)^{\frac{r(r+1)}{2}}}{(2\pi)^{\frac{r}{2}}} (A.2)

and

𝒜~=12(x~,x~)π𝒢+~x~,ρ~π𝒢+12(ρ~,~ρ~)(π𝒢).\tilde{\mathcal{A}}=\frac{1}{2}\Bigl{(}\tilde{x},\tilde{x}\Bigr{)}_{\pi^{*}\mathcal{G}}+\left\langle\widetilde{\nabla}\tilde{x},\tilde{\rho}\right\rangle_{\pi^{*}\mathcal{G}}+\frac{1}{2}\left(\tilde{\rho},\widetilde{\mathcal{R}}\tilde{\rho}\right)_{(\pi^{*}\mathcal{G})^{\vee}}. (A.3)

We wish to show that this form satisfies the following definition.

Definition A.1.

A representative of the Thom class of 𝒢\mathcal{G} is a d𝒢d^{\mathcal{G}}-closed differential form u(𝒢)Ωr(𝒢)u(\mathcal{G})\in\Omega^{r}(\mathcal{G}) such that Vu(𝒢)=1\int_{V}u(\mathcal{G})=1.

Proposition A.2.

The Mathai-Quillen form u(𝒢,)u(\mathcal{G},\nabla) satisfies

  1. (i)

    u(𝒢,)Ωr(𝒢),u(\mathcal{G},\nabla)\in\Omega^{r}(\mathcal{G})\,,

  2. (ii)

    d𝒢u(𝒢,)=0,d^{\mathcal{G}}u(\mathcal{G},\nabla)=0\,,

  3. (iii)

    Vu(𝒢,)=1\int_{V}u(\mathcal{G},\nabla)=1

and hence is a representative of the Thom class of 𝒢\mathcal{G}.

Proof.

  1. (i)

    Since

    𝒜~i=02Ωi(𝒢,Λi(π𝒢)),\tilde{\mathcal{A}}\in\overset{2}{\underset{i=0}{\oplus}}\Omega^{i}\left(\mathcal{G},\Lambda^{i}\left(\pi^{*}\mathcal{G}\right)^{\vee}\right),

    it follows that

    exp(𝒜~)i=0𝑟Ωi(𝒢,Λi(π𝒢)).\exp\left(-\tilde{\mathcal{A}}\right)\in\overset{r}{\underset{i=0}{\oplus}}\Omega^{i}\left(\mathcal{G},\Lambda^{i}\left(\pi^{*}\mathcal{G}\right)^{\vee}\right).

    However, only the component of e𝒜~e^{-\tilde{\mathcal{A}}} in Ωr(𝒢,Λr(π𝒢))\Omega^{r}\left(\mathcal{G},\Lambda^{r}\left(\pi^{*}\mathcal{G}\right)^{\vee}\right) contributes to u(𝒢,)u(\mathcal{G},\nabla). Thus, u(𝒢,)Ωr(𝒢)u(\mathcal{G},\nabla)\in\Omega^{r}(\mathcal{G}).

  2. (ii)

    Since ~\widetilde{\nabla} is compatible with the metric (,)π𝒢\left(\cdot,\cdot\right)_{\pi^{*}\mathcal{G}}, it follows that

    d𝒢𝑑ρ~α~=𝑑ρ~~α~,d^{\mathcal{G}}\int d\tilde{\rho}\,\tilde{\alpha}=\int d\tilde{\rho}\,\widetilde{\nabla}\tilde{\alpha}\,,

    where α~Ω(𝒢,Λ(π𝒢))\tilde{\alpha}\in\Omega\left(\mathcal{G},\Lambda\left(\pi^{*}\mathcal{G}\right)^{\vee}\right). Furthermore,

    (~+x~Aρ~A)𝒜~\displaystyle\left(\widetilde{\nabla}+\tilde{x}_{A}\frac{\partial}{\partial\tilde{\rho}_{A}}\right)\tilde{\mathcal{A}} =(~x~,x~)π𝒢+~x~,ρ~π𝒢12(ρ~,~~ρ~)(π𝒢)\displaystyle=\left(\widetilde{\nabla}\tilde{x},\tilde{x}\right)_{\pi^{*}\mathcal{G}}+\left\langle\widetilde{\mathcal{R}}\tilde{x},\tilde{\rho}\right\rangle_{\pi^{*}\mathcal{G}}-\frac{1}{2}\left(\tilde{\rho},\widetilde{\nabla}\widetilde{\mathcal{R}}\tilde{\rho}\right)_{\left(\pi^{*}\mathcal{G}\right)^{\vee}}
    (~x~,x~)π𝒢~x~,ρ~π𝒢\displaystyle\phantom{=}-\left(\widetilde{\nabla}\tilde{x},\tilde{x}\right)_{\pi^{*}\mathcal{G}}-\left\langle\widetilde{\mathcal{R}}\tilde{x},\tilde{\rho}\right\rangle_{\pi^{*}\mathcal{G}}
    =0,\displaystyle=0\,, (A.4)

    where we have used the Bianchi identity ~~=0\widetilde{\nabla}\,\widetilde{\mathcal{R}}=0. From these results, we obtain

    d𝒢u(𝒢,)\displaystyle d^{\mathcal{G}}u(\mathcal{G},\nabla) =ard𝒢𝑑ρ~exp(𝒜~)\displaystyle=a_{r}\,d^{\mathcal{G}}\int d\tilde{\rho}\,\exp\left(-\tilde{\mathcal{A}}\right)
    =ar𝑑ρ~~exp(𝒜~)\displaystyle=a_{r}\int d\tilde{\rho}\,\widetilde{\nabla}\exp\left(-\tilde{\mathcal{A}}\right)
    =ar𝑑ρ~(~+x~Aρ~A)exp(𝒜~)\displaystyle=a_{r}\int d\tilde{\rho}\,\left(\widetilde{\nabla}+\tilde{x}_{A}\frac{\partial}{\partial\tilde{\rho}_{A}}\right)\exp\left(-\tilde{\mathcal{A}}\right)
    =ar𝑑ρ~[(~+x~Aρ~A)𝒜~]exp(𝒜~)\displaystyle=a_{r}\int d\tilde{\rho}\,\left[-\left(\widetilde{\nabla}+\tilde{x}_{A}\frac{\partial}{\partial\tilde{\rho}_{A}}\right)\tilde{\mathcal{A}}\right]\exp\left(-\tilde{\mathcal{A}}\right)
    =0.\displaystyle=0\,.

    Here, the third equality holds because x~A(/ρ~A)e𝒜~\tilde{x}_{A}\left(\partial/\partial\tilde{\rho}_{A}\right)e^{-\tilde{\mathcal{A}}} contributes nothing to the Grassmann integral.

  3. (iii)
    Vu(𝒢,)\displaystyle\int_{V}u(\mathcal{G},\nabla) =arVexp[12(x~,x~)π𝒢]𝑑ρ~(dx~Aρ~A)rr!\displaystyle=a_{r}\int_{V}\exp\left[-\frac{1}{2}\left(\tilde{x},\tilde{x}\right)_{\pi^{*}\mathcal{G}}\right]\int d\tilde{\rho}\,\frac{\left(-d\tilde{x}^{A}\tilde{\rho}_{A}\right)^{r}}{r!}
    =1(2π)r2V𝑑x~1dx~rexp[12(x~,x~)π𝒢]\displaystyle=\frac{1}{(2\pi)^{\frac{r}{2}}}\int_{V}d\tilde{x}^{1}\wedge\cdots\wedge d\tilde{x}^{r}\,\exp\left[-\frac{1}{2}\left(\tilde{x},\tilde{x}\right)_{\pi^{*}\mathcal{G}}\right]
    =1.\displaystyle=1\,.

Thus, by definition A.1, u(𝒢,)u(\mathcal{G},\nabla) is a representative of the Thom class of 𝒢\mathcal{G}. ∎

A.3 Mathai-Quillen Euler class representative

Now, consider the pullback of the Mathai-Quillen form u(𝒢,)u(\mathcal{G},\nabla) by any section ss of 𝒢\mathcal{G}. We write this as

su(𝒢,)=ar𝑑ρexp(𝒜),s^{*}u(\mathcal{G},\nabla)=a_{r}\int d\rho\,\exp\left(-\mathcal{A}\right), (A.5)

where ara_{r} is given by (A.2) and

𝒜=12(s,s)𝒢+s,ρ𝒢+12(ρ,ρ)𝒢.\mathcal{A}=\frac{1}{2}\left(s,s\right)_{\mathcal{G}}+\left\langle\nabla s,\rho\right\rangle_{\mathcal{G}}+\frac{1}{2}\left(\rho,\mathcal{R}\rho\right)_{\mathcal{G}^{\vee}}. (A.6)
Proposition A.3.

The form su(𝒢,)s^{*}u(\mathcal{G},\nabla) satisfies

  1. (i)

    su(𝒢,)Ωr(M),s^{*}u(\mathcal{G},\nabla)\in\Omega^{r}(M)\,,

  2. (ii)

    dsu(𝒢,)=0.ds^{*}u(\mathcal{G},\nabla)=0\,.

Proof.

  1. (i)

    The proof is similar to that of proposition A.2(i) and uses the fact that

    𝒜i=02Ωi(𝒢,Λi𝒢).\mathcal{A}\in\overset{2}{\underset{i=0}{\oplus}}\Omega^{i}\left(\mathcal{G},\Lambda^{i}\mathcal{G}^{\vee}\right).
  2. (ii)

    The proof is similar to that of proposition A.2(ii) and uses the results

    d𝑑ρα=𝑑ρα,d\int d\rho\,\alpha=\int d\rho\,\nabla\alpha\,,

    where αΩ(𝒢,Λ𝒢)\alpha\in\Omega\left(\mathcal{G},\Lambda\mathcal{G}^{\vee}\right), and

    (+sAρA)𝒜=0.\left(\nabla+s_{A}\frac{\partial}{\partial\rho_{A}}\right)\mathcal{A}=0\,. (A.7)

Proposition A.4.

The dd-cohomology class of su(𝒢,)s^{*}u(\mathcal{G},\nabla) is independent of the section ss.

Proof.

Let sτ=s+τss_{\tau}=s+\tau s^{\prime} be an affine one-parameter family of sections of 𝒢\mathcal{G} and let

𝒜τ=12(sτ,sτ)𝒢+sτ,ρ𝒢+12(ρ,ρ)𝒢.\mathcal{A}_{\tau}=\frac{1}{2}\left(s_{\tau},s_{\tau}\right)_{\mathcal{G}}+\left\langle\nabla s_{\tau},\rho\right\rangle_{\mathcal{G}}+\frac{1}{2}\left(\rho,\mathcal{R}\rho\right)_{\mathcal{G}^{\vee}}.

Then

ddτsτu(𝒢,)\displaystyle\frac{d}{d\tau}s^{*}_{\tau}u(\mathcal{G},\nabla) =arddτ𝑑ρexp(𝒜τ)\displaystyle=a_{r}\,\frac{d}{d\tau}\int d\rho\,\exp\left(-\mathcal{A}_{\tau}\right)
=ar𝑑ρ[(s,sτ)𝒢+s,ρ𝒢]exp(𝒜τ)\displaystyle=-a_{r}\int d\rho\,\Bigl{[}\left(s^{\prime},s_{\tau}\right)_{\mathcal{G}}+\left\langle\nabla s^{\prime},\rho\right\rangle_{\mathcal{G}}\Bigr{]}\exp\left(-\mathcal{A}_{\tau}\right)
=ar𝑑ρ{[+(sτ)AρA]s,ρ𝒢}exp(𝒜τ)\displaystyle=-a_{r}\,\int d\rho\,\left\{\left[\nabla+\left(s_{\tau}\right)_{A}\frac{\partial}{\partial\rho_{A}}\right]\left\langle s^{\prime},\rho\right\rangle_{\mathcal{G}}\right\}\exp\left(-\mathcal{A}_{\tau}\right)
=ar𝑑ρ[+(sτ)AρA][s,ρ𝒢exp(𝒜τ)]\displaystyle=-a_{r}\,\int d\rho\,\left[\nabla+\left(s_{\tau}\right)_{A}\frac{\partial}{\partial\rho_{A}}\right]\Bigl{[}\left\langle s^{\prime},\rho\right\rangle_{\mathcal{G}}\,\exp\left(-\mathcal{A}_{\tau}\right)\Bigr{]}
=ard𝑑ρs,ρ𝒢exp(𝒜τ).\displaystyle=-a_{r}\,d\int d\rho\,\left\langle s^{\prime},\rho\right\rangle_{\mathcal{G}}\,\exp\left(-\mathcal{A}_{\tau}\right).

It follows that

sτ2u(𝒢,)sτ1u(𝒢,)=ardτ1τ2𝑑τ𝑑ρs,ρ𝒢exp(𝒜τ).s^{*}_{\tau_{2}}u(\mathcal{G},\nabla)-s^{*}_{\tau_{1}}u(\mathcal{G},\nabla)=-a_{r}\,d\int^{\tau_{2}}_{\tau_{1}}d\tau\int d\rho\,\left\langle s^{\prime},\rho\right\rangle_{\mathcal{G}}\,\exp\left(-\mathcal{A}_{\tau}\right).

Thus, for arbitrary sections sτ1s_{\tau_{1}} and sτ2s_{\tau_{2}} of 𝒢\mathcal{G}, the dd-closed forms sτ1u(𝒢,)s^{*}_{\tau_{1}}u(\mathcal{G},\nabla) and sτ2u(𝒢,)s^{*}_{\tau_{2}}u(\mathcal{G},\nabla) differ by a dd-exact form and hence are cohomologous. ∎

Corollary A.5.

The form su(𝒢,)s^{*}u(\mathcal{G},\nabla) is cohomologous to the Euler form

e(𝒢,)=1(2π)r2𝑑ρexp[12(ρ,ρ)𝒢]=Pfaff(2π)e(\mathcal{G},\nabla)=\frac{1}{(2\pi)^{\frac{r}{2}}}\int d\rho\,\exp\left[\frac{1}{2}\left(\rho,\mathcal{R}\rho\right)_{\mathcal{G}^{\vee}}\right]=\mathrm{Pfaff}\left(\frac{\mathcal{R}}{2\pi}\right)

and hence is a representative of the Euler class of 𝒢\mathcal{G}.

Proof.

This follows from proposition A.4 upon choosing ss to be the zero section. ∎

Remark A.6.

The top Chern class of a complex vector bundle is equal to the Euler class of the underlying real vector bundle.

Remark A.7.

If ss intersects the zero section of 𝒢\mathcal{G} transversely, then su(𝒢,)s^{*}u(\mathcal{G},\nabla) is Poincaré dual to s1(0)s^{-1}(0), i.e.

Mωsu(𝒢,)=s1(0)ω,\int_{M}\omega\wedge s^{*}u(\mathcal{G},\nabla)=\int_{s^{-1}(0)}\omega\,, (A.8)

where ωΩnr(M)\omega\in\Omega^{n-r}(M) is dd-closed.

Remark A.8.

When n=rn=r, integrating su(𝒢,)s^{*}u(\mathcal{G},\nabla) over MM yields the Euler number of 𝒢\mathcal{G}.

Appendix B Deformation of the pullback of a Mathai-Quillen form

Various analogues of pullbacks of Mathai-Quillen forms were proposed in GaravusoSharpe:Analogues . Let us now discuss the analogue that is most relevant to this paper, i.e. a deformation of the pullback of a Mathai-Quillen form.

Consider deforming su(𝒢,)s^{*}u(\mathcal{G},\nabla) to

ωδs(𝒢,)=ar𝑑ρexp(𝒜δs),\omega_{\delta s}(\mathcal{G},\nabla)=a_{r}\int d\rho\,\exp\left(-\mathcal{A}_{\delta s}\right), (B.1)

where

𝒜δs=𝒜+ρpfp,dϕi(δs)ipep𝒢.\mathcal{A}_{\delta s}=\mathcal{A}+\left\langle\rho^{p^{\prime}}f_{p^{\prime}},d\phi^{i}\left(\delta s\right)_{ip}e^{p}\right\rangle_{\mathcal{G}}. (B.2)

Here, 𝒜\mathcal{A} is given by (A.6) and

(δs)ipΓ(π𝒢πTM).\left(\delta s\right)_{ip}\in\Gamma\left(\pi^{*}\mathcal{G}\otimes\pi^{*}TM\right). (B.3)

The deformation ωδs(𝒢,)\omega_{\delta s}(\mathcal{G},\nabla) and su(𝒢,)s^{*}u(\mathcal{G},\nabla) are special cases of the analogue ωK1\omega_{\textrm{K1}} of su(𝒢,)s^{*}u(\mathcal{G},\nabla) proposed in GaravusoSharpe:Analogues . Briefly,

ωK1[x¯dλx¯][rdχr]exp(𝒜K1)Hrk𝒢(M,rk22det𝒢det2),\omega_{\textrm{K1}}\propto{\textstyle\int\left[{\textstyle\prod}_{\overline{x}}\,d\lambda^{\overline{x}}\,\right]\left[\prod_{r}d\chi^{r}\right]}\exp\left(-\mathcal{A_{\textrm{K1}}}\right)\in H^{\,\textrm{rk}\,\mathcal{G}}\left(M,\wedge^{\textrm{rk}\,\mathcal{F}_{2}}\mathcal{F}^{\vee}_{2}\otimes\det{\mathcal{G}^{\vee}}\otimes\det{\mathcal{F}_{2}}\right),

where 1\mathcal{F}_{1} and 1\mathcal{F}_{1} are holomorphic vector bundles on MM and

𝒜K1=hxx¯sxs¯x¯+χı¯λx¯D¯ı¯s¯x¯+χrλγF~rγ+Fı¯rx¯γχı¯χrλx¯λγ.\mathcal{A_{\textrm{K1}}}=h^{x\overline{x}}s_{x}\overline{s}_{\overline{x}}+\chi^{\overline{\imath}}\lambda^{\overline{x}}\,\overline{D}_{\overline{\imath}}\,\overline{s}_{\overline{x}}\,+\chi^{r}\lambda^{\gamma}\widetilde{F}_{r\gamma}+F_{\overline{\imath}r\overline{x}\gamma}\chi^{\overline{\imath}}\chi^{r}\lambda^{\overline{x}}\lambda^{\gamma}\,.

Here, xx indexes local coordinates along the fibers of 𝒢\mathcal{G}, γ\gamma indexes local coordinates along the fibers of 1\mathcal{F}_{1}, rr indexes local coordinates along the fibers of 2\mathcal{F}^{\vee}_{2}, and ii indexes local coordinates on MM. sΓ(𝒢)s\in\Gamma{(\mathcal{G})}. The map F~:12\widetilde{F}:\mathcal{F}_{1}\rightarrow\mathcal{F}_{2} is smooth and surjective. The curvature term Fı¯rx¯γχı¯χrλx¯λγF_{\overline{\imath}r\overline{x}\gamma}\chi^{\overline{\imath}}\chi^{r}\lambda^{\overline{x}}\lambda^{\gamma} is subject to the constraint

¯ı¯F~rγ=hxx¯sxFı¯rγx¯=hxx¯sxFı¯rx¯γ\overline{\partial}_{\overline{\imath}}\widetilde{F}_{r\gamma}=h^{x\overline{x}}s_{x}F_{\overline{\imath}r\gamma\overline{x}}=-h^{x\overline{x}}s_{x}F_{\overline{\imath}r\overline{x}\gamma}\,

which is imposed physically by supersymmetry. Note that this constraint is consistent with the curvature 2-form being ¯\overline{\partial}-closed by virtue of the Bianchi identity. One may show that

(D¯+hxx¯sxλx¯)𝒜K1=χiχrλγ(¯ı¯F~rγ+hxx¯sxFı¯rx¯γ)=0,\left(\overline{D}+h^{x\overline{x}}s_{x}\frac{\partial}{\partial\lambda^{\overline{x}}}\right)\mathcal{A_{\textrm{K1}}}=\chi^{i}\chi^{r}\lambda^{\gamma}\left(\overline{\partial}_{\overline{\imath}}\widetilde{F}_{r\gamma}+h^{x\overline{x}}s_{x}F_{\overline{\imath}r\overline{x}\gamma}\right)=0\,,

where D¯=χı¯¯ı¯\overline{D}=\chi^{\overline{\imath}}\,\overline{\partial}_{\overline{\imath}}. It follows that ¯ωK1=0\overline{\partial}\,\omega_{\textrm{K1}}=0. Let Y{s=0}MY\equiv\left\{s=0\right\}\subset M and let \mathcal{E}^{\prime} be the restriction to YY of the kernel of the map F~\widetilde{F}. Then

Y𝒪1𝒪k=M𝒪~1𝒪~kωK1,\int_{Y}\mathcal{O}_{1}\wedge\cdots\wedge\mathcal{O}_{k}=\int_{M}\widetilde{\mathcal{O}}_{1}\wedge\cdots\wedge\widetilde{\mathcal{O}}_{k}\wedge\omega_{\textrm{K1}}\,,

where 𝒪~1𝒪~kHdimMrk𝒢(M,rk1rk22)\widetilde{\mathcal{O}}_{1}\wedge\cdots\wedge\widetilde{\mathcal{O}}_{k}\in H^{\dim{M}-\textrm{rk}\,\mathcal{G}}\left(M,\wedge^{\textrm{rk}\,\mathcal{F}_{1}-\textrm{rk}\,\mathcal{F}_{2}}\mathcal{F}^{\vee}_{2}\right) and 𝒪~H(M,1)\widetilde{\mathcal{O}}\in H^{\bullet}\left(M,\wedge^{\bullet}\mathcal{F}^{\vee}_{1}\right) is a lift of 𝒪H(Y,)\mathcal{O}\in H^{\bullet}\left(Y,\wedge^{\bullet}\mathcal{\mathcal{E}}^{\prime\vee}\right). For this reason, ωK1\omega_{\textrm{K1}} is called in GaravusoSharpe:Analogues the (first) kernel construction. See GaravusoSharpe:Analogues for further details. One recovers ωδs(𝒢,)\omega_{\delta s}(\mathcal{G},\nabla) and (when δs=0\delta s=0) su(𝒢,)s^{*}u(\mathcal{G},\nabla) in the special case that 1=TM\mathcal{F}_{1}=TM and 2=𝒢\mathcal{F}_{2}=\mathcal{G} with the map F~:12\widetilde{F}:\mathcal{F}_{1}\rightarrow\mathcal{F}_{2} defined by

Fip=Disp+(δs)ip,F_{ip}=D_{i}s_{p}+\left(\delta s\right)_{ip}\,, (B.4)

where sps_{p} is a holomorphic section of 𝒢\mathcal{G}. This corresponds to \mathcal{E}^{\prime} being a deformation of TYTY, with the deformation determined by δs\delta s. If δs=0\delta s=0, then =TY\mathcal{E}^{\prime}=TY. Note that

¯ı¯Fip=¯ı¯(Disp+(δs)ip)=[D¯ı¯,Di]sp=Rı¯ipp¯gpp¯sp.\overline{\partial}_{\overline{\imath}}\,F_{ip}=\overline{\partial}_{\overline{\imath}}\left(D_{i}s_{p}+\left(\delta s\right)_{ip}\right)=\left[\,\overline{D}_{\overline{\imath}}\,,D_{i}\right]s_{p}=R_{\overline{\imath}ip\overline{p}}\,g^{p\overline{p}}s_{p}\,.
Proposition B.1.

The form ωδs(𝒢,)\omega_{\delta s}(\mathcal{G},\nabla) satisfies

¯ωδs(𝒢,)=0.\overline{\partial}\,\omega_{\delta s}(\mathcal{G},\nabla)=0\,.
Proof.

For 𝒜\mathcal{A} given by (A.6), we have that D¯=0\overline{D}\mathcal{R}=0 and hence

(D¯+sp¯ρp¯)𝒜\displaystyle\left(\overline{D}+s^{\overline{p}}\frac{\partial}{\partial\rho^{\overline{p}}}\right)\mathcal{A} =(spep,D¯sp¯ep¯)𝒢+spep,ρpfp𝒢12(ρ,D¯ρ)𝒢\displaystyle=-\left(s_{p}e^{p},\overline{D}s_{\overline{p}}\,e^{\overline{p}}\right)_{\mathcal{G}}+\left\langle\mathcal{R}s_{p^{\prime}}e^{p^{\prime}},\rho^{p}f_{p}\right\rangle_{\mathcal{G}}-\frac{1}{2}\left(\rho,\overline{D}\mathcal{R}\rho\right)_{\mathcal{G}^{\vee}}
+(spep,D¯sp¯ep¯)𝒢spep,ρpfp𝒢\displaystyle\phantom{=}+\left(s_{p}e^{p},\overline{D}s_{\overline{p}}\,e^{\overline{p}}\right)_{\mathcal{G}}-\left\langle\mathcal{R}s_{p^{\prime}}e^{p^{\prime}},\rho^{p}f_{p}\right\rangle_{\mathcal{G}}
=0.\displaystyle=0\,. (B.5)

It follows that

(D¯+sp¯ρp¯)𝒜δs=(D¯+sp¯ρp¯)[𝒜+ρpfp,dϕi(δs)ipep𝒢]=0.\left(\overline{D}+s^{\overline{p}}\frac{\partial}{\partial\rho^{\overline{p}}}\right)\mathcal{A}_{\delta s}=\left(\overline{D}+s^{\overline{p}}\frac{\partial}{\partial\rho^{\overline{p}}}\right)\left[\mathcal{A}+\left\langle\rho^{p^{\prime}}f_{p^{\prime}},d\phi^{i}\left(\delta s\right)_{ip}e^{p}\right\rangle_{\mathcal{G}}\right]=0\,. (B.6)

Using this result, we obtain

¯ωδs(𝒢,)\displaystyle\overline{\partial}\,\omega_{\delta s}(\mathcal{G},\nabla) =ar¯𝑑ρexp(𝒜δs)\displaystyle=a_{r}\,\overline{\partial}\int d\rho\,\exp\left(-\mathcal{A}_{\delta s}\right)
=ar𝑑ρD¯exp(𝒜δs)\displaystyle=a_{r}\int d\rho\,\overline{D}\exp\left(-\mathcal{A}_{\delta s}\right)
=ar𝑑ρ(D¯+sp¯ρp¯)exp(𝒜δs)\displaystyle=a_{r}\int d\rho\,\left(\overline{D}+s^{\overline{p}}\frac{\partial}{\partial\rho^{\overline{p}}}\right)\exp\left(-\mathcal{A}_{\delta s}\right)
=ar𝑑ρ[(D¯+sp¯ρp¯)𝒜δs]exp(𝒜δs)\displaystyle=a_{r}\int d\rho\,\left[-\left(\overline{D}+s^{\overline{p}}\frac{\partial}{\partial\rho^{\overline{p}}}\right)\mathcal{A}_{\delta s}\right]\exp\left(-\mathcal{A}_{\delta s}\right)
=0.\displaystyle=0\,.

Proposition B.2.

The ¯\overline{\partial}-cohomology class of ωδs(𝒢,)\omega_{\delta s}(\mathcal{G},\nabla) is unchanged by antiholomorphic deformations of ss.

Proof.

Let sα=s+αsp¯ep¯s_{\alpha}=s+\alpha\,s^{\prime}_{\overline{p}}\,e^{\overline{p}} be an affine one parameter family of sections of 𝒢\mathcal{G} and let

𝒜δs,α=12(sα,sα)𝒢+(sα,ρ)𝒢+12(ρ,ρ)𝒢+ρpfp,dϕi(δs)ipep𝒢.\mathcal{A}_{\delta s,\alpha}=\frac{1}{2}\left(s_{\alpha},s_{\alpha}\right)_{\mathcal{G}}+\left(\nabla s_{\alpha},\rho\right)_{\mathcal{G}}+\frac{1}{2}\left(\rho,\mathcal{R}\rho\right)_{\mathcal{G}^{\vee}}+\left\langle\rho^{p^{\prime}}f_{p^{\prime}},d\phi^{i}\left(\delta s\right)_{ip}e^{p}\right\rangle_{\mathcal{G}}.

Then

ddαωδs,α(𝒢,)\displaystyle\frac{d}{d\alpha}\omega_{\delta s,\alpha}(\mathcal{G},\nabla) =arddα𝑑ρexp(𝒜δs,α)\displaystyle=a_{r}\,\frac{d}{d\alpha}\int d\rho\,\exp\left(-\mathcal{A}_{\delta s,\alpha}\right)
=ar𝑑ρ[(sp¯ep¯,spep)𝒢+ρp¯fp¯,D¯sp¯ep¯𝒢]exp(𝒜δs,α)\displaystyle=-a_{r}\int d\rho\,\left[\left(s^{\prime}_{\overline{p}}\,e^{\overline{p}},s_{p}e^{p}\right)_{\mathcal{G}}+\left\langle\rho^{\overline{p}}f_{\overline{p}},\overline{D}s^{\prime}_{\overline{p}^{\prime}}\,e^{\overline{p}^{\prime}}\right\rangle_{\mathcal{G}}\right]\exp\left(-\mathcal{A}_{\delta s,\alpha}\right)
=ar𝑑ρ[(D¯+sp¯ρp¯)ρp¯fp¯,sp¯ep¯𝒢]exp(𝒜δs,α)\displaystyle=-a_{r}\int d\rho\,\left[\left(\overline{D}+s^{\overline{p}}\frac{\partial}{\partial\rho^{\overline{p}}}\right)\left\langle\rho^{\overline{p}}f_{\overline{p}},s^{\prime}_{\overline{p}^{\prime}}\,e^{\overline{p}^{\prime}}\right\rangle_{\mathcal{G}}\right]\exp\left(-\mathcal{A}_{\delta s,\alpha}\right)
=ar𝑑ρ(D¯+sp¯ρp¯)[ρp¯fp¯,sp¯ep¯𝒢exp(𝒜δs,α)]\displaystyle=-a_{r}\int d\rho\,\left(\overline{D}+s^{\overline{p}}\frac{\partial}{\partial\rho^{\overline{p}}}\right)\left[\left\langle\rho^{\overline{p}}f_{\overline{p}},s^{\prime}_{\overline{p}^{\prime}}\,e^{\overline{p}^{\prime}}\right\rangle_{\mathcal{G}}\exp\left(-\mathcal{A}_{\delta s,\alpha}\right)\right]
=ar¯𝑑ρρp¯fp¯,sp¯ep¯𝒢exp(𝒜δs,α).\displaystyle=-a_{r}\,\overline{\partial}\int d\rho\,\left\langle\rho^{\overline{p}}f_{\overline{p}},s^{\prime}_{\overline{p}^{\prime}}\,e^{\overline{p}^{\prime}}\right\rangle_{\mathcal{G}}\,\exp\left(-\mathcal{A}_{\delta s,\alpha}\right).

It follows that

ωδs,α2(𝒢,)ωδs,α1(𝒢,)=ar¯α1α2𝑑α𝑑ρρp¯fp¯,sp¯ep¯𝒢exp(𝒜δs,α),\omega_{\delta s,\alpha_{2}}(\mathcal{G},\nabla)-\omega_{\delta s,\alpha_{1}}(\mathcal{G},\nabla)=-a_{r}\,\overline{\partial}\int^{\alpha_{2}}_{\alpha_{1}}d\alpha\int d\rho\,\left\langle\rho^{\overline{p}}f_{\overline{p}},s^{\prime}_{\overline{p}^{\prime}}\,e^{\overline{p}^{\prime}}\right\rangle_{\mathcal{G}}\exp\left(-\mathcal{A}_{\delta s,\alpha}\right),

which establishes that the ¯\overline{\partial}-cohomology class of ωδs(𝒢,)\omega_{\delta s}(\mathcal{G},\nabla) is unchanged by antiholomorphic deformations of ss. ∎

Remark B.3.

The ¯\overline{\partial}-cohomology class of ωδs(𝒢,)\omega_{\delta s}(\mathcal{G},\nabla) does seem to depend on the choice of the (δs)ip\left(\delta s\right)_{ip}, at least naively. Let (δs)ip,γ=(δs)ip+γ(δs)ip\left(\delta s\right)_{ip,\gamma}=\left(\delta s\right)_{ip}+\gamma\left(\delta s\right)^{\prime}_{ip} and 𝒜δs,γ=𝒜+ρpfp,dϕi(δs)ipγep𝒢.\mathcal{A}_{\delta s,\gamma}=\mathcal{A}+\left\langle\rho^{p^{\prime}}f_{p^{\prime}},d\phi^{i}\left(\delta s\right)^{\gamma}_{ip}e^{p}\right\rangle_{\mathcal{G}}. Then

ddγωδs,γ(𝒢,)\displaystyle\frac{d}{d\gamma}\omega_{\delta s,\gamma}(\mathcal{G},\nabla) =arddγ𝑑ρexp(𝒜δs,γ)\displaystyle=a_{r}\,\frac{d}{d\gamma}\int d\rho\,\exp\left(-\mathcal{A}_{\delta s,\gamma}\right)
=ar𝑑ρρpfp,dϕi(δs)ipep𝒢exp(𝒜δs,γ).\displaystyle=-a_{r}\int d\rho\,\left\langle\rho^{p^{\prime}}f_{p^{\prime}},d\phi^{i}\left(\delta s\right)^{\prime}_{ip}e^{p}\right\rangle_{\mathcal{G}}\exp\left(-\mathcal{A}_{\delta s,\gamma}\right).

It follows that

ωδs,γ2(𝒢,)ωδs,γ1(𝒢,)=arγ1γ2𝑑γ𝑑ρρpfp,dϕi(δs)ipep𝒢exp(𝒜δs,γ),\omega_{\delta s,\gamma_{2}}(\mathcal{G},\nabla)-\omega_{\delta s,\gamma_{1}}(\mathcal{G},\nabla)=-a_{r}\int^{\gamma_{2}}_{\gamma_{1}}d\gamma\int d\rho\,\left\langle\rho^{p^{\prime}}f_{p^{\prime}},d\phi^{i}\left(\delta s\right)^{\prime}_{ip}e^{p}\right\rangle_{\mathcal{G}}\exp\left(-\mathcal{A}_{\delta s,\gamma}\right),

which is at least not obviously ¯\overline{\partial}-exact. The physical meaning of this result is commented on in GaravusoSharpe:Analogues .

References