English

DR/DZ equivalence conjecture and tautological relations

Algebraic Geometry 2020-01-08 v2 Mathematical Physics math.MP

Abstract

In this paper we present a family of conjectural relations in the tautological ring of the moduli spaces of stable curves which implies the strong double ramification/Dubrovin-Zhang equivalence conjecture. Our tautological relations have the form of an equality between two different families of tautological classes, only one of which involves the double ramification cycle. We prove that both families behave the same way upon pullback and pushforward with respect to forgetting a marked point. We also prove that our conjectural relations are true in genus 00 and 11 and also when first pushed forward from Mg,n+m\overline{\mathcal{M}}_{g,n+m} to Mg,n\overline{\mathcal{M}}_{g,n} and then restricted to Mg,n\mathcal{M}_{g,n}, for any g,n,m0g,n,m\geq 0. Finally we show that, for semisimple CohFTs, the DR/DZ equivalence only depends on a subset of our relations, finite in each genus, which we prove for g2g\leq 2. As an application we find a new formula for the class λg\lambda_g as a linear combination of dual trees intersected with kappa and psi classes, and we check it for g3g \leq 3.

Keywords

Cite

@article{arxiv.1705.03287,
  title  = {DR/DZ equivalence conjecture and tautological relations},
  author = {Alexandr Buryak and Jérémy Guéré and Paolo Rossi},
  journal= {arXiv preprint arXiv:1705.03287},
  year   = {2020}
}

Comments

v2: 64 pages, typos corrected, accepted in Geometry and Topology, adapted to the journal style

R2 v1 2026-06-22T19:41:34.803Z