we consider the semigroup $s$ of highest weights appearing in tensor powers $v^{otimes k}$ of a finite dimensional representation $v$ of a connected reductive group. we describe the cone generated by $s$ as the cone over the weight polytope of $v$ intersected with the positive weyl chamber. from this we get a description for the asymptotic of the number of highest weights appearing in $v^{otime...

We consider the semigroup $S$ of highest weights appearing in tensor powers $V^{otimes k}$ of a finite dimensional representation $V$ of a connected reductive group. We describe the cone generated by $S$ as the cone over the weight polytope of $V$ intersected with the positive Weyl chamber. From this we get a description for the asymptotic of the number of highest weights appearing in $V^{otime...

By δ and wk denote the minimum degree and minimum degree-sum (weight) of a k-vertex path in a given graph, respectively. For every 3-polytope, w2 6 13 (Kotzig, 1955) and w3 6 21 (Ando, Iwasaki, Kaneko, 1993), where both bounds are sharp. For every 3-polytope with δ > 4, we have sharp bounds w2 6 11 (Lebesgue, 1940) and w3 6 17 (Borodin, 1997). Madaras (2000) proved that every triangulated 3-pol...

It is a longstanding open problem whether there exists a polynomial size description of the perfect matching polytope. We give a partial answer to this question by proving the following result. The polyhedron defined by the constraints of the perfect matching polytope which are active at a given perfect matching can be obtained as the projection of a compact polyhedron. Thus there exists a comp...

It is well-known that the intersection of the matching polytope with a cardinality constraint is integral [8]. We prove a similar result for the polytope corresponding to the transportation problem with market choice (TPMC) (introduced in [4]) when the demands are in the set {1, 2}. This result generalizes the result regarding the matching polytope and also implies that some special classes of ...

The volume and the number of lattice points of the permutohedron Pn are given by certain multivariate polynomials that have remarkable combinatorial properties. We give 3 different formulas for these polynomials. We also study a more general class of polytopes that includes the permutohedron, the associahedron, the cyclohedron, the Stanley-Pitman polytope, and various generalized associahedra r...

Given a preference system (G, ≺) and an integral weight function defined on the edge set of G (not necessarily bipartite), the maximum-weight stable matching problem is to find a stable matching of (G, ≺) with maximum total weight. We study this N P-hard problem using linear programming and polyhedral approaches, and show that the Rothblum system for defining the fractional stable matching poly...

here‎, ‎we aim to develop a new algorithm for solving a multiobjective linear programming problem‎. ‎the algorithm is to obtain a solution which approximately meets the decision maker's preferences‎. ‎it is proved that the proposed algorithm always converges to a weak efficient solution and at times converges to an efficient solution‎. ‎numerical examples and a simulation study are used to...

A code polytope is defined to be the convex hull in R n of the points in {0, 1}n corresponding to the codewords of a binary linear code. This paper contains a collection of results concerning the structure of such code polytopes. A survey of known results on the dimension and the minimal polyhedral representation of a code polytope is first presented. We show how these results can be extended t...