Mobility Edge for the Anderson Model on the Bethe Lattice

Seminar: 
Analysis
Event time: 
Thursday, November 13, 2025 - 4:00pm
Location: 
KT 201
Speaker: 
Patrick Lopatto
Speaker affiliation: 
University of North Carolina at Chapel Hill
Event description: 

We discuss recent work that pinpoints the spectral decomposition for the Anderson tight-binding model with an unbounded random potential on the Bethe lattice of sufficiently large degree. We prove that there exist a finite number of mobility edges separating intervals of pure-point spectrum from intervals of absolutely continuous spectrum, confirming a prediction of Abou-Chacra, Thouless, and Anderson. A central component of the proof is a monotonicity result for the leading eigenvalue of a certain transfer operator, which governs the decay rate of fractional moments for the tight-binding model’s off-diagonal resolvent entries. This is joint work with Amol Aggarwal. We will also draw connections to the problem of establishing a mobility edge in the spectrum of heavy-tailed random matrices, which was considered in recent work with Amol Aggarwal and Charles Bordenave.

Research Area(s):