English

Tautological Intersection Numbers and Order-Consecutive Partition Sequences

Combinatorics 2023-08-01 v1 Algebraic Geometry

Abstract

By recent work of Afandi, it is known that tautological intersection numbers on the moduli space of stable nn-pointed genus gg curves can be arranged into families of Ehrhart polynomials, {Ld}\{L_{\vec{d}}\}, for partial polytopal complexes. In particular, the ff^*-vector of LdL_{\vec{d}} is known to be integral and non-negative. In this paper, we show that both the ff^*-vector and hh^*-vector have an enumerative interpretation in the special case that d=(1,1,,1)\vec{d} = (1, 1, \dots, 1). The ff^*-vector counts order-consecutive partition sequences of [n+1][n+1] and the hh^*-vector is a binomial coefficient. Furthermore, we conjecture that, for all d\vec{d}, the ff^*-vector of LdL_{\vec{d}} always forms a log-concave sequence, and we verify this conjecture in the case that d=(1,1,,1)\vec{d} = (1, 1, \dots, 1).

Keywords

Cite

@article{arxiv.2307.15825,
  title  = {Tautological Intersection Numbers and Order-Consecutive Partition Sequences},
  author = {Finn Bjarne Jost},
  journal= {arXiv preprint arXiv:2307.15825},
  year   = {2023}
}
R2 v1 2026-06-28T11:43:14.561Z