Spectral expansion in random regular graphs

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

• Ewan Cassidy (University of Cambridge)
• Wednesday 05 November 2025, 13:30-14:30
• MR4, CMS.

If you have a question about this talk, please contact Julia Wolf.

Fixed-degree expanders are sparse yet highly connected graphs. This quality is captured by their spectral gap—the difference between the largest and second largest eigenvalues of their adjacency matrix. A celebrated result of Friedman states that a random d-regular graph on n vertices is a near-optimal expander with high probability. I will discuss a generalization of this result to a regime where the number of vertices grows quasi-exponentially in n. The proof draws on ideas from representation theory and considerations of word maps on the symmetric group.

This talk is part of the Discrete Analysis Seminar series.

This talk is included in these lists:

• All CMS events
• All Talks (aka the CURE list)
• CMS Events
• DPMMS Lists
• DPMMS Pure Maths Seminar
• DPMMS info aggregator
• DPMMS lists
• Discrete Analysis Seminar
• Hanchen DaDaDash
• Interested Talks
• MR4, CMS
• School of Physical Sciences
• bld31

Note that ex-directory lists are not shown.