PETAK, 04. juni 2010. u 14 sati:


Mirjana Isakovic-Ilic, Ekonomski fakultet, Univerzitet u Beogradu
TABLOI I SEKVENTI

Supstrukturne logike su sve one logike cija se sekventna formulacija moze dobiti iz Gencenovog sistema LK, eliminacijom i/ili restrikcijom pojedinih strukturnih pravila. Automatizacija postupka za utvrdjivanje dokazivosti zadate formule, u nekoj od odlucivih supstrukturnih logika, veoma je zanimljiv, cesto tezak zadatak. Jedna od metoda, koja se koristi u formulaciji dokazivaca teorema je metoda tabloa.

Petak, 18.06.2010. u 14h, sala 2, MI SANU, BGD

Benjamin Matschke, Technische Universitat - Berlin
OPTIMAL BOUNDS ON THE COLORED TVERBERG PROBLEM AND A TRANSVERSAL TVERBERG-VRECICA TYPE GENERALIZATION

Abstract: This is joint work with Pavle V. Blagojevic and Gunter M. Ziegler. We present an optimal colorful Tverberg-Vrecica type transversal theorem about transversals meeting convex hulls of rainbow partitions of several colored set in Euklidean space. This is a "unifying" theorem. It implies among others a new tight colored Tverberg theorem for primes, which in turn implies the Barany-Larman conjecture (1992) for primes plus one, as well as variations of the famous ham sandwich theorem. On the surface these seem to have not much in common. Along the proof we obtain two results of independent interest: We present calculate the cohomological index for some joins of chessboard complexes, and establish a new Borsuk-Ulam type theorem for (Z_p)^m-equivariant bundles that generalizes results of Volovikov (1996) and Zivaljevic (1999).

Petak, 25.06.2010. u 14h, sala 2, SANU, BGD

Novi projektni ciklus
SASTANAK ODELJENJA ZA MATEMATIKU POSVECEN NOVOM PROJEKTNOM CIKLUSU