Eigenfunctions Seminar

Title: Quantitative Diagonalizability
Speaker: Nikhil Srivastava (UC Berkeley, USA)
Date: 16 August 2019
Time: 3 – 5 pm (with a 15 minute break at 3:45)
Venue: LH-1, Mathematics Department

A diagonalizable matrix has linearly independent eigenvectors. Since the set of nondiagonalizable matrices has measure zero, every matrix is the limit of diagonalizable matrices. We prove a quantitative version of this fact: every n x n complex matrix is within distance delta of a matrix whose eigenvectors have condition number poly(n)/delta, confirming a conjecture of E. B. Davies. The proof is based on regularizing the pseudospectrum with a complex Gaussian perturbation.

Joint work with J. Banks, A. Kulkarni, S. Mukherjee.


Contact: +91 (80) 2293 2711, +91 (80) 2293 2265 ;     E-mail: chair.math[at]iisc[dot]ac[dot]in
Last updated: 17 Aug 2019