Extensions of Yamamoto-Nayak's Theorem

Abstract

A result of Nayak asserts that $\underset{m\to \infty }{\lim }|A^m{|}^{1/m}$ exists for each $n\times n$ complex matrix $A$, where $|A|=(A^{\ast }A{)}^{1/2}$, and the limit is given in terms of the spectral decomposition. We extend the result of Nayak, namely, we prove that the limit of $\underset{m\to \infty }{\lim }|B{A}^{m}C{|}^{1/m}$ exists for any $n\times n$ complex matrices $A$, $B$, and $C$ where $B$ and $C$ are nonsingular; the limit is obtained and is independent of $B$. We then provide generalization in the context of real semisimple Lie groups.

15 pages