Noticias en español
Fair Auctions with Asymmetrically Informed Bidders
Abstract: (With Aranyak Mehta and Uri Nadav) Agents often arrive to auctions with different levels of informations about their own value for the object sold. In such asymmetric settings, it may be optimal to charge different reservation prices to discriminate between bidders. However, it is often infeasible to expressly treat different bidders in the same auction differently, particularly in on-line settings. We characterize optimal nondiscriminatory mechanisms in the presence of informational asymmetries and compares them to the revenue of unconstrained optimal auctions. We find the revenue...
Read MorePreferential Attachment Random graphs with edge-step functions
Abstract: Nowadays, modeling and understanding the evolution and properties of concrete networks are important questions for many areas in the scientific community. The huge amount of data generated these days combined with new computing power allowed us to see concretely how many entities, such as our own society, are organized and connected. These findings naturally motivated the investigation of many models that intended to reproduce the properties observed empirically. In this seminar, in its first moment, we will introduce which kind of properties one desires to see on a random graph...
Read MoreA new method for showing nonexistence of solutions for a generalized Brezis-Nirenberg problem
Abstract: In this talk I will present new results on the nonexistence of solutions for a generalized hyperbolic Brezis-Nirenberg problem. Here we combine a classical Pohozaev argument with a generalized Hardy inequality. This is joint work with Soledad Benguria (U. Wisconsin).
Read MoreA Median-Type Condition for Graph Tiling
Abstract: Komlos determined the asymptotically optimal minimum degree condition for covering a given proportion of vertices of a host graph by vertex-disjoint copies of a fixed graph H. We show that the minimum degree condition can be relaxed in the sense that we require only a given fraction of vertices to have the prescribed degree. Joint work with Diana Piguet.
Read MoreExtension Complexity.
Abstract: A polytope Q is called an extension of a polytope P if P is a projection of Q. The extension complexity of a polytope is the minimum number of inequalities needed to describe any of its extensions. In this talk I will describe some results related to extension complexities of several important polytopes arising in combinatorial optimization and discuss how extension complexity can be used to model computational difficulty of solving problems.
Read MoreStrong Algorithms for the Ordinal Matroid Secretary Problem
Abstract: A general technique and analysis for the matroid secretary problem is presented and then we show how to achieve a 4-competitive algorithm for the case of graphic matroids.
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