English

Bier spheres of extremal volume and generalized permutohedra

Combinatorics 2021-08-03 v1 Metric Geometry

Abstract

A Bier sphere Bier(K)=KΔKBier(K) = K\ast_\Delta K^\circ, defined as the deleted join of a simplicial complex and its Alexander dual KK^\circ, is a purely combinatorial object (abstract simplicial complex). Here we study a hidden geometry of Bier spheres by describing their natural geometric realizations, compute their volume, describe an effective criterion for their polytopality, and associate to KK a natural fan Fan(K)Fan(K), related to the Braid fan. Along the way we establish a connection of Bier spheres of maximal volume with recent generalizations of the classical Van Kampen-Flores theorem and clarify the role of Bier spheres in the theory of generalized permutohedra.

Keywords

Cite

@article{arxiv.2108.00618,
  title  = {Bier spheres of extremal volume and generalized permutohedra},
  author = {Filip D. Jevtić and Rade T. Živaljević},
  journal= {arXiv preprint arXiv:2108.00618},
  year   = {2021}
}