Pseudospectra and Simultaneous Power Control

Maëva Ostermann

We prove that, for $M>0$ and $n,m\ge 2$, we can find two $10\times 10$ matrices $A$ and $B$ with identical pseudospectra such that we have simultaneously $\Vert A^n\Vert /\Vert B^n\Vert >M$ and $\|A…