Amitsur Algebra

2015 Dec 24

Amitsur Algebra: Michael Larsen (Indiana U)

12:00pm to 1:15pm

Location: 

Manchester Building (room 209), Jerusalem, Israel
Title: Character values on compact simple Lie groups Abstract: This work is part of a joint project with Aner and others to find upper bounds for values of irreducible characters in two related settings: compact simple Lie groups and finite groups of Lie type. I will discuss the first case, presenting bounds of the form $$|\chi(g)| = O(\chi(1)^\alpha),$$
2015 Dec 03

Amitsur Algebra: Boris Plotkin (Hebrew U)

12:00pm to 1:15pm

Location: 

Manchester Building (room 209), Jerusalem, Israel
Title: Algebraic Geometry in an arbitrary variety of algebras and Algebraic Logic Abstract: I will speak about a system of notions which lead to interesting new problems for groups and algebras as well as to reinterpretation of some old ones.
2017 Dec 28

Amitsur Algebra: Ari Shnidman (Boston College), "The behavior of rational points in one-parameter families"

12:00pm to 1:00pm

Location: 

Ross 70, Math Building, Givat Ram
Title: The behavior of rational points in one-parameter families Abstract: How often does a "random" algebraic plane curve f(x,y) = 0 have a solution with rational coordinates? In one-parameter "twist" families of elliptic curves, Goldfeld conjectured that there should be a rational point exactly half of the time. Recent progress towards this conjecture makes use of Selmer groups, and I'll explain the geometric idea underlying their construction. I'll also describe results for families of curves of higher genus, and abelian varieties of higher dimension.
2017 Jan 26

Amitsur Algebra: Lev Glebsky, "Approximations of groups and equations over groups"

12:00pm to 1:00pm

Location: 

Manchester Building, Room 209
Title: Approximations of groups and equations over groups. Abstract: The talk is largely based on the paper which may be found here: https://authors.elsevier.com/a/1UN3b4~FOr6ze Abstract: Let G be a group and K a class of groups. I define a notion of approximation of G by K and give several characterizations of approximable by K groups. For example, the sofic groups, defined by B. Weiss, are the groups approximable by symmetric (or alternating) groups. In the case of sofic groups we have that the following are equivalent:
2017 Jan 19

Amitsur Algebra: Yiftach Barnea, "Old and New Results on Subgroup Growth in Pro-p Groups."

12:00pm to 1:00pm

Location: 

Manchester Building, Room 209
Title: Old and New Results on Subgroup Growth in Pro-p Groups. Abstract: I will survey our current knowledge about subgroup growth in pro-p growth. In particular I will present new solutions to long standing open problems in the area: 1. What is the minimal subgroup growth of non-$p$-adic analytic pro-$p$ groups? (Joint work with Benjamin Klopsch and Jan-Christoph Schlage-Puchta.) 2. What are the subgroup growths of the Grigorchuk group and the Gupta-Sidki groups? (Joint work with Jan-Christoph Schlage-Puchta.)
2017 Jun 22

Amitsur Algebra: Jan Dobrowolski

12:00pm to 1:00pm

Location: 

Manchester 209
Title: Inp-minimal ordered groups. Abstract. The main goal of the talk is to present the proof of the theorem stating that inp-minimal (left)-ordered groups are abelian. This generalizes a previous result of P. Simon for bi-ordered inp-minimal groups.
2016 Dec 29

Amitsur Algebra: Igor Rivin, "Random integer matrices"

12:00pm to 1:00pm

Location: 

Manchester Building, Room 209
Title: Random integer matrices Abstract: I will discuss various models of random integer matrices, and their (occasionally surprising) properties. Some of the work discussed is joint with E. Fuchs.
2016 Dec 08

Amitsur Algebra: George Glauberman (Chicago)

12:00pm to 1:15pm

Location: 

Manchester Building, Room 209
Title: Fixed points of finite groups on modules Abstract: Suppose G is a finite group, p is a prime, S is a Sylow p-subgroup of G, and V is a G-module over a field of characteristic p. In some situations, an easy calculation shows that the fixed points of G on V are the same as the fixed points of the normalizer of S in G. Generalizations of this result have been obtained previously to study the structure of G for p odd. We plan to describe a new generalization for p = 2. (This is part of joint work with J. Lynd that removes the classification of finite simple groups
2017 Jun 29

Amitsur Algebra: Nir Gadish

12:00pm to 1:00pm

Location: 

Manchester 209
Title: Stability patterns in representation theory and applications Abstract: Many natural sequences of objects come equipped with group actions, e.g. the symmetric group on n letters acting on a space X_n. This leads to fundamental instability of invariants, such as homology, arising from the representation theory of the sequence of groups. Representation stability is a new and increasingly important set of ideas that describe a sense in which such sequence of representations (of different groups) stabilizes.

Pages