Inequalities for Matrix Powers and Absolute Values: A Generalization of London’s Conjecture
Author(s):
Hanjo Täubig
Abstract:
We provide an inequality for absolute row and column sums of the powers of a complex
matrix. This inequality generalizes several other inequalities. As a result, it provides an
inequality that compares the absolute entry sum of the matrix powers to the sum of
the powers of the absolute row/column sums. This provides a proof for a conjecture of
London, which states that for all complex matrices $A$ such that $|A|$ is symmetric, we have
$sum(|A^p|) \le \sum_{i=1}^n r_i(|A|)^p$.