Abstract
AbstractWe study multipliers M (bounded operators commuting with translations) on weighted spaces L ω p (ℝ), and establish the existence of a symbol µM for M, and some spectral results for translations S t and multipliers. We also study operators T on the weighted space L ω p (ℝ+) commuting either with the right translations S t , t ∈ ℝ+, or left translations P +S −t , t ∈ ℝ+, and establish the existence of a symbol µ of T. We characterize completely the spectrum σ(S t ) of the operator S t proving that $\sigma (S_t ) = \{ z \in \mathbb{C}:|z| \leqslant e^{t\alpha _0 } \} ,$ where α 0 is the growth bound of (S t )t≥0. A similar result is obtained for the spectrum of (P +S −t ), t ≥ 0. Moreover, for an operator T commuting with S t , t ≥ 0, we establish the inclusion
Reference12 articles.
1. Montgomery Evolutionary semigroups and Lyapunov theorems in Banach spaces http dx org;Latushkin;Funct Anal,1995
2. Spectra of the translations and Wiener - Hopf operators on ω in press;Petkova;Proc Amer Math Soc
3. Approximate point spectrum of a weighted shift http dx org;Ridge;Trans Amer Math Soc,1970
4. A Short Course on Operator Semigroups New York;Engel;Universitext,2006
5. A short proof for the stability theorem for positive semigroups on http dx org;Weis;Proc Amer Math Soc,1998