English

Limiting Betti distributions of Hilbert schemes on $n$ points

Algebraic Geometry 2022-04-06 v2 Combinatorics Number Theory

Abstract

Hausel and Rodriguez-Villegas recently observed that work of G\"ottsche, combined with a classical result of Erd\H{o}s and Lehner on integer partitions, implies that the limiting Betti distribution for the Hilbert schemes (C2)[n](\mathbb{C}^2)^{[n]} on nn points, as n+,n\rightarrow +\infty, is a \textit{Gumbel distribution}. In view of this example, they ask for further such Betti distributions. We answer this question for the quasihomogeneous Hilbert schemes ((C2)[n])Tα,β((\mathbb{C}^2)^{[n]})^{T_{\alpha,\beta}} that are cut out by torus actions. We prove that their limiting distributions are also of Gumbel type. To obtain this result, we combine work of Buryak, Feigin, and Nakajima on these Hilbert schemes with our generalization of the result of Erd\H{o}s and Lehner, which gives the distribution of the number of parts in partitions that are multiples of a fixed integer A2.A\geq 2. Furthermore, if pk(A;n)p_k(A;n) denotes the number of partitions of nn with exactly kk parts that are multiples of AA, then we obtain the asymptotic pk(A,n)24k214(nAk)k2342(11A)k214k!Ak+12(2π)ke2π16(11A)(nAk), p_k(A,n)\sim \frac{24^{\frac k2-\frac14}(n-Ak)^{\frac k2-\frac34}}{\sqrt2\left(1-\frac1A\right)^{\frac k2-\frac14}k!A^{k+\frac12}(2\pi)^k}e^{2\pi\sqrt{\frac1{6}\left(1-\frac1A\right)(n-Ak)}}, a result which is of independent interest.

Keywords

Cite

@article{arxiv.2112.05279,
  title  = {Limiting Betti distributions of Hilbert schemes on $n$ points},
  author = {Michael Griffin and Ken Ono and Larry Rolen and Wei-Lun Tsai},
  journal= {arXiv preprint arXiv:2112.05279},
  year   = {2022}
}

Comments

Minor revision addressing referee comments