Let $B$ be a Banach space and $T$
a bounded linear operator on $B.$ A celebrated theorem of Ansari
says that whenever $T$ is hypercyclic so is any power $T^n$. We
provide a very natural proof of this theorem by building on an
approach by Bourdon. We also explore an extension to a non linear
setting of a theorem of León-Saavedra and Müller which says that
for $\lambda \in \mathbb C$ and $|\lambda|=1$ the operator $\lambda
T$ is hypercyclic whenever $T$ is.
@article{1251832374,
author = {Marano, Miguel and Salas, H\'ector N.},
title = {Maps with dense orbits: Ansari's theorem revisited and the infinite
torus},
journal = {Bull. Belg. Math. Soc. Simon Stevin},
volume = {16},
number = {1},
year = {2009},
pages = { 481-492},
language = {en},
url = {http://dml.mathdoc.fr/item/1251832374}
}
Marano, Miguel; Salas, Héctor N. Maps with dense orbits: Ansari's theorem revisited and the infinite
torus. Bull. Belg. Math. Soc. Simon Stevin, Tome 16 (2009) no. 1, pp. 481-492. http://gdmltest.u-ga.fr/item/1251832374/