English

Generalized degree polynomials of trees

Combinatorics 2026-01-15 v2

Abstract

The generalized degree polynomial GT(x,y,z)\mathbf{G}_T(x,y,z) of a tree TT is an invariant introduced by Crew that enumerates subsets of vertices by size and number of internal and boundary edges. Aliste-Prieto et al. proved that GT\mathbf{G}_T is determined linearly by the chromatic symmetric function XT\mathbf{X}_T, introduced by Stanley. We present several classes of information about TT that can be recovered from GT\mathbf{G}_T and hence also from XT\mathbf{X}_T. Examples of such information include the double-degree sequence of TT, which enumerates edges of TT by the pair of degrees of their endpoints, and the leaf adjacency sequence of TT, which enumerates vertices of TT by degree and number of adjacent leaves. We also discuss a further generalization of GT\mathbf{G}_T that enumerates tuples of vertex sets and show that this is also determined by XT\mathbf{X}_T.

Keywords

Cite

@article{arxiv.2411.18972,
  title  = {Generalized degree polynomials of trees},
  author = {Ricky Ini Liu and Michael Tang},
  journal= {arXiv preprint arXiv:2411.18972},
  year   = {2026}
}

Comments

19 pages, 3 figures; added remarks following proof of Prop 2.4

R2 v1 2026-06-28T20:15:37.508Z