Session 17. Functional Analysis: relations to Complex Analysis and PDE

Abel's functional equation and eigenvalues of composition operators on spaces of real analytic functions

José Bonet, Universitat Politècnica de València, 
The talk is based on the joint work with P. DomaƄski
We present a full description of eigenvalues and eigenvectors of composition operators \(C_\varphi\) acting on the space \(A(R)\) of real analytic function on the real line \(R\) for a real analytic self map \(\varphi\), as well as an isomorphic description of corresponding eigenspaces. We also completely characterize those self maps \(\varphi\) for which Abel's equation \(f\circ \varphi =f+1\) has a real analytic solution on the real line. Finally, we find cases when the operator \(C_\varphi\) has roots using a constructed embedding of \(\varphi\) into a so-called real analytic iteration semigroups.
Print version