ὅδε οἶκος, ὦ ἑταῖρε, μνημεῖον ἐστιν ζῴων τῶν σοφῶν ἀνδρῶν, καὶ τῶν ἔργων αὐτῶν

Mathematical Colloquim

 

PROGRAM


ODELJENJE ZA MATEMATIKU

MATEMATIČKOG INSTITUTA SANU
                       OPŠTI MATEMATIČKI SEMINAR

NA MATEMATIČKOM FAKULTETU U BEOGRADU



PROGRAM ZA JUN 2011.

 

 

Sreda, 22.06.2011. u 14h, sala 2, MI SANU, BGD

Sergej Melihov, Steklov institut RAN
COMBINATORIAL METHODS IN EMBEDDING THEORY

Abstract: We offer the following explanation of the statement of the Kuratowski graph planarity criterion and of 6/7 of the statement of the Robertson-Seymour-Thomas intrinsic linking criterion. Let us call a cell complex 'dichotomial' if to every cell there corresponds a unique cell with the complementary set of vertices. Then every dichotomial cell complex is PL homeomorphic to a sphere; there exist precisely two 3-dimensional dichotomial cell complexes, and their 1-skeleta are K_5 and K_{3,3}; and precisely six 4-dimensional ones, and their 1-skeleta all but one graphs of the Petersen family. In higher dimensions n>2, we observe that in order to characterize those compact n-polyhedra that embed in S^{2n} in terms of finitely many "prohibited minors", it suffices to establish finiteness of the list of all (n-1)-connected n-dimensional finite cell complexes that do not embed in S^{2n} yet all their proper subcomplexes and proper cell-like combinatorial quotients embed there. Our main result is that this list contains the n-skeleta of (2n+1)-dimensional dichotomial cell complexes. The 2-skeleta of 5-dimensional dichotomial cell complexes include (apart from the three joins of the i-skeleta of (2i+2)-simplices) at least ten non-simplicial complexes. The talk is based on the preprint http://arxiv.org/abs/1103.5457

Petak, 24.06.2011. u 14h, sala 2, SANU, BGD

Shahar Nevo, Department of Mathematics and Computer Science, Bar-Ilan University, Israel
Q_\alpha-NORMALITY AND ENTIRE FUNCTIONS

Abstract: We introduce the notion of Q_\alpha-normality, which is an extension of the notion of Q_1-normality (Quasi-normality) to higher orders \alpha, where alpha is an arbitrary ordinal number. Then we explain why for countable \alpha there is an entire function f=f_\alpha, such that f(n\ast z), n=1,2,3.... is "exact" Q_\alpha -normal family. This is a common work with Shai Gul.


Rukovodioci Odeljenja za matematiku Matematickog instituta SANU i Opsteg matematickog seminara na Matematickom fakultetu u Beogradu, Stevan Pilipovic i Sinisa Vrecica predlazu zajednicki program rada naucnih sastanaka.

Predavanja ce se odrzavati na Matematickom Institutu (sala 2), petkom sa pocetkom u 14 casova. Odeljenje za matematiku je opsti seminar sa najduzom tradicijom u Institutu.

Svakog meseca, jedno predavanje ce biti odrzano na Matematickom Fakultetu u terminu koji ce biti posebno odredjen.

Molimo sve zainteresovane ucesnike u radu naucnih sastanaka da posebno obrate paznju na vreme odrzavanja svakog sastanka. Na Matematickom fakultetu su moguce izmene termina.

Obavestenje o programu naucnih sastanaka ce biti objavljeno na oglasnim tablama MI (Beograd), MF (Beograd), PMF (Novi Sad), PMF (Nis) i PMF (Kragujevac).

Odeljenje za matematiku Matematickog instituta SANU

Stevan Pilipovic

Opsti matematicki seminar na Matematickom fakultetu u Beogradu,

Sinisa Vrecica


Ako zelite da se obavestenja o Vasim naucnim skupovima pojave u Newsletter of EMS (European Mathematical Society) i na Internetu na lokaciji EMS, onda se obratite na emsvesti@mi.sanu.ac.rs gde cete dobiti format obavestenja.