Spectral gaps for random Schreier graphs

Add to your list(s) Download to your calendar using vCal

• Ewan Cassidy (University of Cambridge)
• Wednesday 08 October 2025, 10:15-11:15
• Seminar Room 1, Newton Institute.

If you have a question about this talk, please contact nobody.

OGGW03 - Spectral gaps

I will discuss a generalization of Friedman’s theorem, focusing on the spectral gap of the random regular Schreier graphs associated with the action of S_n on K_n—tuples of distinct elements in {1,...,n}. The proof relies on the `polynomial method’, a new approach to strong convergence of Chen, Garza—Vargas, Tropp and van Handel, combined with new group theoretic inputs. A key ingredient is a new asymptotic bound on the expected character of a random permutation obtained via a word map, which is expressed in terms of the dimension of the corresponding representation. 

This talk is part of the Isaac Newton Institute Seminar Series series.

This talk is included in these lists:

• All CMS events
• Featured lists
• INI info aggregator
• Isaac Newton Institute Seminar Series
• School of Physical Sciences
• Seminar Room 1, Newton Institute
• bld31

Note that ex-directory lists are not shown.