Logarithmic double ramification cycles
Abstract
Let be a vector of integers which sum to . The double ramification cycle on the moduli space of curves is the virtual class of an Abel-Jacobi locus of pointed curves satisfying The Abel-Jacobi construction requires log blow-ups of to resolve the indeterminacies of the Abel-Jacobi map. Holmes has shown that admits a canonical lift to the logarithmic Chow ring, which is the limit of the intersection theories of all such blow-ups. The main result of the paper is an explicit formula for which lifts Pixton's formula for . The central idea is to study the universal Jacobian over the moduli space of curves (following Caporaso, Kass-Pagani, and Abreu-Pacini) for certain stability conditions. Using the criterion of Holmes-Schwarz, the universal double ramification theory of Bae-Holmes-Pandharipande-Schmitt-Schwarz applied to the universal line bundle determines the logarithmic double ramification cycle. The resulting formula, written in the language of piecewise polynomials, depends upon the stability condition (and admits a wall-crossing study). Several examples of logarithmic and higher double ramification cycles are computed.
Keywords
Cite
@article{arxiv.2207.06778,
title = {Logarithmic double ramification cycles},
author = {D. Holmes and S. Molcho and R. Pandharipande and A. Pixton and J. Schmitt},
journal= {arXiv preprint arXiv:2207.06778},
year = {2025}
}
Comments
97 pages, 6 figures. Substantial revision following referee reports. Comments very welcome