6 papers
Improving SDP bounds for minimizing quadratic functions over the l1-ball
Immanuel M. Bomze, Florian Frommlet, Martin Rubey
In this note, we establish superiority of the so-called copositive bound over a bound suggested by Nesterov for the quadratic problem to minimize a quadratic form over the l1-ball.…
Transcendence of generating functions of walks on the slit plane
Martin Rubey
Consider a single walker on the slit plane, that is, the square grid Z^2 without its negative x-axis, who starts at the origin and takes his steps from a given set S. Mireille Bous…
Cantorian Tableaux and Permanents
Srečko Brlek, Michel Mendès France, John Michael Robson +1
This article could be called "theme and variations" on Cantor's celebrated diagonal argument. Given a square nxn tableau T=(a_i^j) on a finite alphabet A, let L be the set of its r…
The h-vector of a ladder determinantal ring cogenerated by 2x2 minors is log-concave
Martin Rubey
We show that the h-vector of a ladder determinantal ring cogenerated by M=[u_1|v_1] is log-concave. Thus we prove an instance of a conjecture of Stanley, resp. Conca and Herzog
A determinantal formula for the Hilbert series of one-sided ladder determinantal rings
Christian Krattenthaler, Martin Rubey
We give a formula that expresses the Hilbert series of one-sided ladder determinantal rings, up to a trivial factor, in form of a determinant. This allows the convenient computatio…
A `nice' bijection for a content formula for skew semistandard Young tableaux
Martin Rubey
Based on Schützenberger's evacuation and a modification of jeu de taquin, we give a bijective proof of an identity connecting the generating function of reverse semistandard Young…