Mathematical Physics

Speaker: 
Jacob Shapiro
Speaker Affiliation: 
Princeton
Speaker Link: 
https://web.math.princeton.edu/~shapiro/

January 23, 2024

PIMS Lounge
ESB 4133
Canada

This Seminar is hybrid.

https://ubc.zoom.us/j/61468702267?pwd=aFR4SCszMUQ3VERNWmwwcFMwV21CUT09

Meeting ID: 614 6870 2267

Passcode: 356890

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Abstract: 

Random band matrices provide a simple model for studying the metal-insulator transition of random operators, the prominent example of which is the Anderson model. According to the famous sqrt(N) conjecture, N x N random matrices with non-zero entries only within a diagonal band of width W exhibit a phase transition between GUE behavior and Anderson localization, precisely at W ~ sqrt(N). After giving some background on this problem, we will first present a unique special “chiral” model where the conjecture can be shown to hold, and then proceed to study the full model, proving localization holds at all energies when W ≪ N^{1/4}. This latter result uses the fractional moment method and an adaptive Mermin-Wagner-style shift.
 

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