Tree-width in Algebraic Complexity

Issue title: Bridging Logic and Computer Science: to Johann A. Makowsky for his 60th birthday

Article type: Research Article

Authors: Meer, Klaus

Affiliations: Institute of Computer Science, BTU Cottbus, Konrad-Wachsmann-Allee 1, D-03046 Cottbus, Germany. E-mail: meer@informatik.tu-cottbus.de

Abstract: The paper surveys some of the author's work studying the algorithmic importance of the tree-width notion in algebraic frameworks. Two approaches are described. The first gives an algorithmicmeta-theoremfor certain logically characterized propertieswithin the Blum-Shub-Smale BSS model of computation over the reals. The second reports on recent joint work with P. Koiran relating Boolean complexity and Valiant's approach to study families of polynomial systems over infinite fields and their complexity. We define particular families of polynomials via bounding the tree-width of suitably attached graphs and study the expressive power of the resulting families. The work described here is partially co-authoredwith and partially verymuch influenced by previous work of Janos A. Makowsky.

Keywords: Tree-width, Real Number Computations, Descriptive Complexity, Valiant's Model, Dedicated to Johann A. Makowsky on the occasion of his 60th birthday

DOI: 10.3233/FI-2010-235

Journal: Fundamenta Informaticae, vol. 98, no. 4, pp. 391-409, 2010