Title
Intermediate Sums on Polyhedra: Computation and Real Ehrhart Theory
Abstract
We study intermediate sums, interpolating between integrals and discrete sums, which were introduced by A. Barvinok in [Computing the Ehrhart quasi-polynomial of a rational simplex. Math. Comp. 75 (2006), 1449-1466]. For a given polytope p with facets parallel to rational hyperplanes and a rational subspace L, we integrate a given polynomial function h over all lattice slices of the polytope p parallel to the subspace L and sum up the integrals. We first develop an algorithmic theory of parametric intermediate generating functions. Then we study the Ehrhart theory of these intermediate sums, that is, the dependence of the result as a function of a dilation of the polytope. We provide an algorithm to compute the resulting Ehrhart quasi-polynomials in the form of explicit step-polynomials. These formulas are naturally valid for real (not just integer) dilations and thus provide a direct approach to real Ehrhart theory.
Year
DOI
Venue
2010
10.1112/S0025579312000101
MATHEMATIKA
Keywords
DocType
Volume
generating function,computational geometry
Journal
59
Issue
ISSN
Citations 
1
0025-5793
4
PageRank 
References 
Authors
0.57
5
4
Name
Order
Citations
PageRank
Velleda Baldoni1394.82
Nicole Berline2293.31
Matthias KöPpe319120.95
Michèle Vergne4598.21