Matthias Walter

Assistant Professor at University of Twente (Enschede, NL)

Relaxation strength for multilinear optimization: McCormick strikes back

  • Matthias Walter
    • Categories (Mixed) Integer Linear Programming, Nonlinear Optimization, Polyhedra Tags , , , , ,

    We consider linear relaxations for multilinear optimization problems. In a recent paper, Khajavirad proved that the extended flower relaxation is at least as strong as the relaxation of any recursive McCormick linearization (Operations Research Letters 51 (2023) 146-152). In this paper we extend the result to more general linearizations, and present a simpler proof. Moreover, … Read more

    Recognizing Series-Parallel Matrices in Linear Time

  • Matthias Walter
    • Categories Graphs and Matroids Tags ,

    A series-parallel matrix is a binary matrix that can be obtained from an empty matrix by successively adjoining rows or columns that are copies of an existing row/column or have at most one 1-entry. Equivalently, series-parallel matrices are representation matrices of graphic matroids of series-parallel graphs, which can be recognized in linear time. We propose … Read more