Pratyush Sarkar (University of California, San Diego)
Date
Wednesday July 9, 20252:30 pm - 3:30 pm
Location
319 JEFFERY HALLDynamics, Geometry and Groups Seminar
Wednesday, July 9, 2025
Time: 2:30 p.m. Place: Jeffery Hall, Room 319
Speaker: Pratyush Sarkar (University of California, San Diego)
Title: Effective equidistribution of translates of tori in arithmetic homogeneous spaces and applications
Abstract: A celebrated theorem of Eskin鈥揗ozes鈥揝hah gives an asymptotic counting formula for the number of integral (n x n)-matrices with a prescribed irreducible (over the integers/rationals) integral characteristic polynomial. We obtain a power saving error term for the counting problem for (3 x 3)-matrices. We do this by using the connection to homogeneous dynamics and proving effective equidistribution of translates of tori in SL_3(R)/SL_3(Z). A key tool is that the limiting Lie algebra corresponding to the translates of tori is a certain nilpotent Lie algebra. This allows us to use the recent breakthrough work of Lindenstrauss鈥揗ohammadi鈥揥ang鈥揧ang on effective versions of Shah's/Ratner's theorems. We actually study the phenomenon more generally for any semisimple Lie group which we may discuss if time permits.