| Texto completo | |
| Autor(es): |
Carmo, Joao R.
;
Noor, S. Waleed
Número total de Autores: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | JOURNAL OF OPERATOR THEORY; v. 87, n. 1, p. 20-pg., 2022-12-01. |
| Resumo | |
A Hilbert space operator U is called universal (in the sense of Rota) if every Hilbert space operator is similar to a multiple of U restricted to one of its invariant subspaces. It follows that the invariant subspace problem for Hilbert spaces is equivalent to the statement that all minimal invariant subspaces for U are one dimensional. In this article we characterize all linear fractional composition operators C-phi f = f circle phi f that have universal translates on both the classical Hardy spaces H-2(C+) and H-2(D) of the half-plane and the unit disk, respectively. The new example here is the composition operator on H-2 (D) with affine symbol phi a (z) = az + (1-a) for 0 < a < 1. This leads to strong characterizations of minimal invariant subspaces and eigenvectors of C-phi a and offers an alternative approach to the ISP. (AU) | |
| Processo FAPESP: | 17/09333-3 - Espaços de Hilbert de funções holomorfas com aplicações à teoria espectral e teoria analítica de números |
| Beneficiário: | Sahibzada Waleed Noor |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |