A non-reflexive Banach space with all contractions mean ergodic

A Mean Ergodic Theorem For Asymptotically Quasi-Nonexpansive Affine Mappings in Banach Spaces Satisfying Opial's Condition

Ergodic sequences of probability measures on commutative hypergroups

We study conditions on a sequence of probability measures {µ n } n on a commutative hyper-group K, which ensure that, for any representation π of K on a Hilbert space Ᏼ π and for any ξ ∈ Ᏼ π , (K π x (ξ)dµ n (x)) n converges to a π-invariant member of Ᏼ π. 1. Introduction. The mean ergodic theorem was originally formulated by von Neu-mann [13] for one-parameter unitary groups in Hilbert space. ...

Completely continuous Banach algebras

 For a Banach algebra $fA$, we introduce ~$c.c(fA)$, the set of all $phiin fA^*$ such that $theta_phi:fAto  fA^*$ is a completely continuous operator, where $theta_phi$ is defined by $theta_phi(a)=acdotphi$~~ for all $ain fA$. We call $fA$, a completely continuous Banach algebra if $c.c(fA)=fA^*$. We give some examples of completely continuous Banach algebras and a sufficient condition for an o...

Unrestricted Products of Contractions in Banach Spaces

Let X be a reflexive Banach space such that for any x 6= 0 the set {x∗ ∈ X∗ : ‖x∗‖ = 1 and x∗(x) = ‖x‖} is compact. We prove that any unrestricted product of of a finite number of (W ) contractions on X converges weakly. Recall a (bounded) linear operator on a Banach space X is said to be contraction if ‖Tx‖ ≤ ‖x‖ for all x ∈ X . T is said to satisfy condition (W ) if {xn} is bounded and ‖xn‖ −...

Fourier Analysis Methods in Operator Ergodic Theory on Super-reflexive Banach Spaces

On reflexive spaces trigonometrically well-bounded operators (abbreviated “twbo’s”) have an operator-ergodic-theory characterization as the invertible operators U whose rotates “transfer” the discrete Hilbert averages (C, 1)-boundedly. Twbo’s permeate many settings of modern analysis, and this note treats advances in their spectral theory, Fourier analysis, and operator ergodic theory made poss...