Suppose both A and B are n×n nonsingular M-matrices. An estimate from below for the smallest eigenvalue τ(A○B-1) (in modulus) of the Hadamard product A○B-1 of A and B-1 is derived. As a special case, we obtain the inequality τ(A ○ A-1) ≥ 2/n (n ≥ 2). © 2003 Elsevier Inc. All rights reserved.
Chen, S. (2004). A lower bound for the minimum eigenvalue of the Hadamard product of matrices. Linear Algebra and Its Applications, 378(1–3), 159–166. https://doi.org/10.1016/j.laa.2003.09.011