English

Variational principles for spectral radius of weighted endomorphisms of $C(X,D)$

Functional Analysis 2019-09-20 v2 Dynamical Systems Operator Algebras

Abstract

We give formulas for the spectral radius of weighted endomorphisms aα:C(X,D)C(X,D)a\alpha: C(X,D)\to C(X,D), aC(X,D)a\in C(X,D), where XX is a compact Hausdorff space and DD is a unital Banach algebra. Under the assumption that α\alpha generates a partial dynamical system (X,φ)(X,\varphi), we establish two kinds of variational principles for r(aα)r(a\alpha): using linear extensions of (X,φ)(X,\varphi) and using Lyapunov exponents associated with ergodic measures for (X,φ)(X,\varphi). This requires considering (twisted) cocycles over (X,φ)(X,\varphi) with values in an arbitrary Banach algebra DD, and thus our analysis can not be reduced to any of mutliplicative ergodic theorems known so far. The established variational principles apply not only to weighted endomorphisms but also to a vast class of operators acting on Banach spaces that we call abstract weighted shifts associated with α:C(X,D)C(X,D)\alpha: C(X,D)\to C(X,D). In particular, they are far reaching generalizations of formulas obtained by Kitover, Lebedev, Latushkin, Stepin and others. They are most efficient when D=B(F)D=\mathcal{B}(F), for a Banach space FF, and endomorphisms of B(F)\mathcal{B}(F) induced by α\alpha are inner isometric. As a by product we obtain a dynamical variational principle for an arbitrary operator bB(F)b\in \mathcal{B}(F) and that it's spectral radius is always a Lyapunov exponent in some direction vFv\in F, when FF is reflexive.

Keywords

Cite

@article{arxiv.1812.04267,
  title  = {Variational principles for spectral radius of weighted endomorphisms of $C(X,D)$},
  author = {B. K. Kwasniewski and A. V. Lebedev},
  journal= {arXiv preprint arXiv:1812.04267},
  year   = {2019}
}

Comments

37 pages. This is a version accepted in Trans. Amer. Math. Soc. (added some more examples and section 6 "Concluding remarks and potential applications")