Mixing operators and small subsets of the circle

Frédéric Bayart (1) , Etienne Matheron (2)

1 LMBP - Laboratoire de Mathématiques Blaise Pascal
2 LML - Laboratoire de Mathématiques de Lens

We provide complete characterizations, on Banach spaces with cotype 2, of those linear operators which happen to be weakly mixing or strongly mixing transformations with respect to some nondegenerate Gaussian measure. These characterizations involve two families of small subsets of the circle: the countable sets, and the so-called sets of uniqueness for Fourier-Stieltjes series. The most interesting part, i.e. the sufficient conditions for weak and strong mixing, is valid on an arbitrary (complex, separable) Fréchet space.

Mots clés: Hypercyclic operators; Gaussian measures; mixing; unimodular eigenvalues; countable sets; sets of extended uniqueness; cotype 2

Domaines: Analyse fonctionnelle [math.FA]

Frédéric Bayart, Etienne Matheron. Mixing operators and small subsets of the circle. 2011. ⟨hal-00648673⟩