On the polyhedral complexity of the integer points in a hyperball

  • Authors:
  • Valentin E. Brimkov;Reneta P. Barneva

  • Affiliations:
  • Mathematics Department, SUNY Buffalo State College, Buffalo, NY 14222, USA;Department of Computer Science, SUNY Fredonia, NY 14063, USA

  • Venue:
  • Theoretical Computer Science
  • Year:
  • 2008

Quantified Score

Hi-index 5.23

Visualization

Abstract

Let B^n be a hyperball in R^n, n=2, and denote B"Z^n=B^n@?Z^n. Define polyhedral facet complexity of B"Z^n as FC(B"Z^n)=min"P{f"n"-"1(P)} where P is an enclosing polyhedron for B"Z^n (i.e., P"Z=P@?Z^n=B"Z^n) and f"n"-"1(P) is the number of the (n-1)-facets of P. Analogously, define polyhedral vertex complexity of B"Z^n as VC(B"Z^n)=min"P{f"0(P)} where P is an enclosing polyhedron for B"Z^n and f"0(P) is the number of the 0-facets (vertices) of P. Upper bounds for FC(B"Z^n) follow from a well-known bound for the number of facets and vertices of the convex hull of B"Z^n [I. Barany, D.G. Larman, The convex hull of the integer points in a large ball, Math. Ann. 312 (1998) 167-181]. In this note we provide the first nontrivial lower bounds on FC(B"Z^n) and VC(B"Z^n).