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2018-19

Seminars are held on Thursdays at 14:00 in Room B3.02 - Mathematics Institute

Organisers: Inna Capdeboscq and Dmitriy Rumynin

Term 1 - 2018/19

October 11: Robert Gilman (Stevens Institute of Technology)

Title: Algorithmic complexity in finitely presented groups

Abstract: Most decision problems for finitely presented groups are
undecidable, but practical partial algorithms do exist. Generic case
complexity is often used to estimate the efficacy of these algorithms. We
will review generic case complexity, point out some shortcomings and
suggest an improvement.

 

October 18: Geoffrey Robinson

Title: Large centralizrs in finite groups.

Abstract: We discuss recent joint work with Bob Guralnick, partly inspired by the famous Brauer-Fowler paper. We prove a number of results ( some using the classification of finite simple groups (CFSG), some not) which bound the index of the Fitting subgroup of a finite group G in terms of centralizers of certain elements of G, especially involutions. We also provide a CFSG-free bound on the maximum dimension of the fixed-point space of an involution in a finite linear group.