Sparse robust expander sp;p;

  Hong Liu
 University of warwick
 
September 22, 2016 (1 Mehr 1395) at 14:00-15:00

Abstract: I will present an embedding strategy using a notion of sub-linear expander first introduced by Komlos and Szemeredi. As applications, it settles a conjecture of Mader in 1999 on large clique subdivisions in graphs without 4-cycles.

 Sharp bound on the number of maximal sum-free subsets of integers 

  Maryam Sharifzadeh 
 University of warwick
 
September 22, 2016 (1 Mehr 1395) at 11:00-12:00

Gruss type inequalities for positive linear maps

 Mohammad Sal Moslehian
Ferdowsi University of Mashhad 
September 14, 2016 (24 Shahrivar 1395) at 16:00-17:00

Abstract: The Gruss inequality as a reverse of Chebyshev inequality has been developed by several mathematicians in different contents such as inner product spaces, Hilbert modules, quadrature formulae and linear functionals. In this talk, we investigate several new Gruss type inequalities for positive linear maps on finite or infinite dimensional C*-algebras.

Symmetries  of partial Latinrectangles via graphs

Rebecca J. Stones

Nankai University, China
July 31, 2016 (10 Mordad 1395) at 16:00-17:00

Abstract: Partial Latin rectangles are matrices without repeated s ymbols in any row or column,  allowing the  possibility of empty  cells . In this talk, we extend the nation of "Latin  square graphs" to  partial Latin rectangles, which  we use to study the symmetry  groups of partial Latin rectangles.

 Generalized Smoluchowski Equations and Scalar Conservation Laws(Photos)

Fraydoun Rezakhanlou
University of California, Berkeley
July 17, 2016 (27 Tir 1395) at 10:00-11:00

Abstract: By a classical result of Bertoin, if initially a solution to Burgers' equation is a Levy process without positive jumps, then this property persists at later times. According to a theorem of Groeneboom, a white noise initial data also leads to a Levy process at positive times. Menon and Srinivasan observed that in both aforementioned results the evolving Levy measure satisfies a Smoluchowski-type equation. They also conjectured that a similar phenomenon would occur if instead of Burgers' equation, we solve a general scalar conservation law with a convex flux function. Though a Levy process may evolve to a Markov process that in most cases is not Levy. The corresponding jump kernel would satisfy a generalized Smoluchowski equation. Along with Dave Kaspar, we show that a variant of this conjecture is true for monotone solutions to scalar conservation laws.

Geometric graphs and graph limits (Photos)

Mahya Ghandehari
University of Delaware, USA
Jun 16, 2016 (27 Khordad 1395) at 11:00-12:00

Abstract: Many real-life networks can be modeled by stochastic processes with a spatial embedding. For example, in a social network, vertices may be considered as members of a social space, where the coordinates represent the interests and background of the users, and the probability of a link occurring between two vertices decreases as their metric distance increases. A fundamental question is to determine whether a given network is compatible with a spatial model. We show how to recognize graph sequences produced by random graph processes that have a natural embedding into the real line, using techniques from the theory of graph limits as pioneered by Lovasz, Szegedy and others. This talk is based on work joint with Huda Chuangpishit, Matt Hurshman, Jeannette Janssen, and Nauzar Kalyaniwalla. 

Ian M. Wanless
Monash University (Melbourne, Australia)
Jun 6, 2016 (17 Khordad 1395) at 16:00-17:00

On the annihilation of cohomology

Shokrollah Salarian
University of Isfahan and IPM
Jun 2, 2016 (13 Khordad 1395) at 11:00-12:00