A new look at local maps on algebraic structures of matrices and operators

In a very general setting, we introduce a new type of local maps, a new sort of reflexive closure of a given class of transformations relative to a given operation that we call operational reflexive closure, and a corresponding concept of reflexivity. We calculate the operational reflexive closures...

Teljes leírás

Elmentve itt :
Bibliográfiai részletek
Szerző: Molnár Lajos
Dokumentumtípus: Cikk
Megjelent: 2022
Sorozat:NEW YORK JOURNAL OF MATHEMATICS 28
Tárgyszavak:
mtmt:32808481
Online Access:http://publicatio.bibl.u-szeged.hu/37360
Leíró adatok
Tartalmi kivonat:In a very general setting, we introduce a new type of local maps, a new sort of reflexive closure of a given class of transformations relative to a given operation that we call operational reflexive closure, and a corresponding concept of reflexivity. We calculate the operational reflexive closures of some important classes of transformations and significantly strengthen former 2-reflexivity results concerning the automorphism groups of various operator structures. A typical new result is this: if phi is a map from the unitary group over a separable infinite dimensional Hilbert space into itself with the property that for any pair V, W of unitaries there is a group automorphism alpha(v,w) of the unitary group such that phi(V)phi(W) = alpha(v,w)(VW), then either phi itself or -phi is a group automorphism. This result substantially generalizes a former one on the 2-reflexivity of the automorphism group of the unitary group. We also present open problems and questions for further study.
Terjedelem/Fizikai jellemzők:557-579
ISSN:1076-9803