Title
Quadratic Gröbner bases of twinned order polytopes.
Abstract
Let P and Q be finite partially ordered sets on d = { 1 , ¿ , d } , and O ( P ) ¿ R d and O ( Q ) ¿ R d their order polytopes. The twinned order polytope of P and Q is the convex polytope Δ ( P , - Q ) ¿ R d which is the convex hull of O ( P ) ¿ ( - O ( Q ) ) . It follows that the origin of R d belongs to the interior of Δ ( P , - Q ) if and only if P and Q possess a common linear extension. It will be proved that, when the origin of R d belongs to the interior of Δ ( P , - Q ) , the toric ideal of Δ ( P , - Q ) possesses a quadratic Gröbner basis with respect to a reverse lexicographic order for which the variable corresponding to the origin is the smallest. Thus in particular if P and Q possess a common linear extension, then the twinned order polytope Δ ( P , - Q ) is a normal Gorenstein Fano polytope.
Year
DOI
Venue
2016
10.1016/j.ejc.2015.12.014
Eur. J. Comb.
DocType
Volume
Issue
Journal
54
C
ISSN
Citations 
PageRank 
0195-6698
2
0.46
References 
Authors
0
2
Name
Order
Citations
PageRank
Takayuki Hibi19430.08
Kazunori Matsuda220.46