“…Proof. The proof here follows closely Pixton's proof of polynomiality in [17,Appendix]. We will use [17, Proposition A1], but with Pixton's r replaced with r − 1 (which we assume to be large enough).…”
Section: Proof Of Theoremmentioning
confidence: 91%
“…Proof. Once again we follow Pixton's proof in [17,Appendix]. Let Q be a polynomial in N variables with (p-integral) Q-coefficients.…”
Section: Proof Of Theoremmentioning
confidence: 99%
“…Let Q be a polynomial in N variables with (p-integral) Q-coefficients. According to [17,Equation 33], the sum…”
Relations among tautological classes on M g,n are obtained via the study of Witten's r-spin theory for higher r. In order to calculate the quantum product, a new formula relating the r-spin correlators in genus 0 to the representation theory of sl 2 (C) is proven. The Givental-Teleman classification of CohFTs is used at two special semisimple points of the associated Frobenius manifold. At the first semisimple point, the R-matrix is exactly solved in terms of hypergeometric series. As a result, an explicit formula for Witten's r-spin class is obtained (along with tautological relations in higher degrees). As an application, the r = 4 relations are used to bound the Betti numbers of R * (M g ). At the second semisimple point, the form of the R-matrix implies a polynomiality property in r of Witten's r-spin class.In the Appendix (with F. Janda), a conjecture relating the r = 0 limit of Witten's r-spin class to the class of the moduli space of holomorphic differentials is presented. 0 Introduction 0.1 Overview Let M g,n be the moduli space of stable genus g curves with n markings. Letbe the subring of tautological classes in cohomology 1 . The subringsare defined together as the smallest system of Q-subalgebras closed under push-forward via all boundary and forgetful maps, see [6,7,12]. There has been substantial progress in the understanding of RH * (M g,n ) since the study began in the 1980s [21]. The subject took a new turn in 2012 with the family of relations conjectured in [25]. We refer the reader to [23] for a survey of recent developments.Witten's r-spin class defines a Cohomological Field Theory (CohFT) for each integer r ≥ 2. Witten's 2-spin theory concerns only the fundamental classes of the moduli spaces of curves (and leads to no new geometry). In our previous paper [24], we used Witten's 3-spin theory to construct a family of relations among tautological classes of M g,n equivalent (in cohomology) to the relations proposed in [25]. Our goal here is to extend our study of tautological relations to Witten's r-spin theory for all r ≥ 3.Taking [24] as a starting point, Janda has completed a formal study of tautological relations obtained from CohFTs. Two results of Janda are directly relevant here:(i) The relations for r = 3 are valid in Chow [14,16].(ii) The relations for r ≥ 4 are implied by the relations for r = 3 [14,15]. By (i) and (ii) together, all of the r-spin relations that we find will be valid in Chow. However, since our methods here are cohomological, we will use the language of cohomology throughout the paper.
“…Proof. The proof here follows closely Pixton's proof of polynomiality in [17,Appendix]. We will use [17, Proposition A1], but with Pixton's r replaced with r − 1 (which we assume to be large enough).…”
Section: Proof Of Theoremmentioning
confidence: 91%
“…Proof. Once again we follow Pixton's proof in [17,Appendix]. Let Q be a polynomial in N variables with (p-integral) Q-coefficients.…”
Section: Proof Of Theoremmentioning
confidence: 99%
“…Let Q be a polynomial in N variables with (p-integral) Q-coefficients. According to [17,Equation 33], the sum…”
Relations among tautological classes on M g,n are obtained via the study of Witten's r-spin theory for higher r. In order to calculate the quantum product, a new formula relating the r-spin correlators in genus 0 to the representation theory of sl 2 (C) is proven. The Givental-Teleman classification of CohFTs is used at two special semisimple points of the associated Frobenius manifold. At the first semisimple point, the R-matrix is exactly solved in terms of hypergeometric series. As a result, an explicit formula for Witten's r-spin class is obtained (along with tautological relations in higher degrees). As an application, the r = 4 relations are used to bound the Betti numbers of R * (M g ). At the second semisimple point, the form of the R-matrix implies a polynomiality property in r of Witten's r-spin class.In the Appendix (with F. Janda), a conjecture relating the r = 0 limit of Witten's r-spin class to the class of the moduli space of holomorphic differentials is presented. 0 Introduction 0.1 Overview Let M g,n be the moduli space of stable genus g curves with n markings. Letbe the subring of tautological classes in cohomology 1 . The subringsare defined together as the smallest system of Q-subalgebras closed under push-forward via all boundary and forgetful maps, see [6,7,12]. There has been substantial progress in the understanding of RH * (M g,n ) since the study began in the 1980s [21]. The subject took a new turn in 2012 with the family of relations conjectured in [25]. We refer the reader to [23] for a survey of recent developments.Witten's r-spin class defines a Cohomological Field Theory (CohFT) for each integer r ≥ 2. Witten's 2-spin theory concerns only the fundamental classes of the moduli spaces of curves (and leads to no new geometry). In our previous paper [24], we used Witten's 3-spin theory to construct a family of relations among tautological classes of M g,n equivalent (in cohomology) to the relations proposed in [25]. Our goal here is to extend our study of tautological relations to Witten's r-spin theory for all r ≥ 3.Taking [24] as a starting point, Janda has completed a formal study of tautological relations obtained from CohFTs. Two results of Janda are directly relevant here:(i) The relations for r = 3 are valid in Chow [14,16].(ii) The relations for r ≥ 4 are implied by the relations for r = 3 [14,15]. By (i) and (ii) together, all of the r-spin relations that we find will be valid in Chow. However, since our methods here are cohomological, we will use the language of cohomology throughout the paper.
We analyze Chiodo's formulas for the Chern classes related to the r -th roots of the suitably twisted integer powers of the canonical class on the moduli space of curves. The intersection numbers of these classes with ψ-classes are reproduced via the Chekhov-Eynard-Orantin topological recursion. As an application, we prove that the Johnson-Pandharipande-Tseng formula for the orbifold Hurwitz numbers is equivalent to the topological recursion for the orbifold Hurwitz numbers. In particular, this gives a new proof of the topological recursion for the orbifold Hurwitz numbers.
“…A stable curve is of compact type if and only if its Jacobian is an abelian variety, and the Abel-Jacobi map s A naturally extends to the moduli space of curves of compact type M ct g,n ⊂ M g,n (see formula (14) in [GZ14A] or Section 0.2.3 in [JPPZ16]). To define this extension, let (C, p 1 , .…”
Section: The θ-Relations and Pixton's Double Ramification Cycle Relat...mentioning
Abstract. We show that the vanishing of the (g + 1)-st power of the theta divisor on the universal abelian variety X g implies, by pulling back along a collection of Abel-Jacobi maps, the vanishing results in the tautological ring of M g,n of Looijenga, Ionel, Graber-Vakil, and Faber-Pandharipande. We also show that Pixton's double ramification cycle relations, which generalize the theta vanishing relations and were recently proved by the first and third authors, imply Theorem ⋆ of Graber and Vakil, and we provide an explicit algorithm for expressing any tautological class on M g,n of sufficiently high codimension as a boundary class.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.