Noticias en español
Completely mixed linear games and irreducibility concepts for Z-transformations over self-dual cones.
Abstract: In the setting of a self-dual cone in a finite-dimensional real inner product space (in particular, over a symmetric cone in an Euclidean Jordan algebra), we consider zero-sum linear games. Motivated by dynamical systems, we concentrate on $Z$-transformations (which are generalizations of $Z$-matrices). It is known that a $Z$-transformation with positive (game) value is completely mixed (thus yielding uniqueness of optimal strategies). The present talk deals with the case of value zero. Motivated by the matrix-game result that a $Z$-matrix with value zero is completely...
Read MoreSecond-order dynamical systems associated with a class of quasiconvex functions.
Abstract: In this talk, we examine second-order gradient dynamical systems for smooth strongly quasiconvex functions, without assuming the usual Lipschitz continuity of the gradient. We establish that these systems exhibit exponential convergence of the trajectories towards an optimal solution. Furthermore, we extend our analysis to the broader quasiconvex setting by incorporating Hessian-driven damping into the second-order dynamics. Finally, we demonstrate that explicit discretizations of these dynamical systems result in gradient-based methods, and we prove the linear convergence of these...
Read MoreSpread measures on perfect matchings in regular pairs.
Abstract: The notion of spread distributions on copies of a given graph (or family of graphs) has played a crucial role in recent developments in probabilistic combinatorics, particularly in studying thresholds in random graphs. In this talk, I will show how to construct a spread distribution on perfect matching in regular pairs, which can be used together with the regularity lemma to find well-behaved embeddings of sparse graphs.
Read MoreAn overview of some coloring parameters for (n,m)-graphs.
Abstract: Graph coloring is one of the most famous problems in graph theory. The most natural question to ask in this framework is whether or not a given family of graphs has a finite chromatic number. As graph homomorphisms generalize coloring, we study the notion of homomorphisms for (n,m)-graphs. Due to their various types of adjacencies, the (n,m)-graphs manage to capture complex relational structures and are useful for mathematical modeling. For instance, the Query Evaluation Problem (QEP) in graph databases, the immensely popular databases that are now used to handle highly...
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