Reduction of symmetric semidefinite programs using the regular $$\ast$$-representation

  • Authors:
  • Etienne de Klerk;Dmitrii V. Pasechnik;Alexander Schrijver

  • Affiliations:
  • Tilburg University, Department of Econometrics and Operations Research, Faculty of Economics and Business Administration, P.O. Box 90153, 5000, LE Tilburg, The Netherlands;Tilburg University, Department of Econometrics and Operations Research, Faculty of Economics and Business Administration, P.O. Box 90153, 5000, LE Tilburg, The Netherlands;CWI and University of Amsterdam. CWI, P.O. Box 90153, Kruislaan 413, 1098, Amsterdam, SJ, The Netherlands

  • Venue:
  • Mathematical Programming: Series A and B
  • Year:
  • 2007

Quantified Score

Hi-index 0.00

Visualization

Abstract

We consider semidefinite programming problems on which a permutation group is acting. We describe a general technique to reduce the size of such problems, exploiting the symmetry. The technique is based on a low-order matrix $$*$$-representation of the commutant (centralizer ring) of the matrix algebra generated by the permutation matrices. We apply it to extending a method of de Klerk et al. that gives a semidefinite programming lower bound to the crossing number of complete bipartite graphs. It implies that cr(K 8,n ) ≥ 2.9299n 2 − 6n, cr(K 9,n ) ≥ 3.8676n 2 − 8n, and (for any m ≥ 9) $$\lim_{n\to\infty}\frac{{\rm cr}(K_{m,n})}{Z(m,n)}\geq 0.8594\frac{m}{m-1},$$ where Z(m,n) is the Zarankiewicz number $$\lfloor\frac{1}{4}(m-1)^2\rfloor\lfloor\frac{1}{4}(n-1)^2\rfloor$$, which is the conjectured value of cr(K m,n). Here the best factor previously known was 0.8303 instead of 0.8594.