| dc.creator | Chiumiento, Eduardo Hernán | |
| dc.creator | Di Iorio y Lucero, M. E. | |
| dc.date | 2013 | |
| dc.date | 2019-11-13T17:24:09Z | |
| dc.identifier | http://sedici.unlp.edu.ar/handle/10915/85541 | |
| dc.identifier | issn:0022-247X | |
| dc.description | Let I be a symmetrically-normed ideal of the space of bounded operators acting on a Hilbert space H. Let {pi}1w(1≤w≤∞) be a family of mutually orthogonal projections on H. The pinching operator associated with the former family of projections is given by P:I→I,P(x)=∑i=1wpixpi. Let UI denote the Banach-Lie group of the unitary operators whose difference with the identity belongs to I. We study geometric properties of the orbit UI(P)={LuPLu*:u∈UI}, where Lu is the left representation of UI on the algebra B(I) of bounded operators acting on I. The results include necessary and sufficient conditions for UI(P) to be a submanifold of B(I). Special features arise in the case of the ideal K of compact operators. In general, UK(P) turns out to be a non complemented submanifold of B(K). We find a necessary and sufficient condition for UK(P) to have complemented tangent spaces in B(K). We also show that UI(P) is a covering space of another orbit of pinching operators. | |
| dc.description | Facultad de Ciencias Exactas | |
| dc.format | application/pdf | |
| dc.format | 103-118 | |
| dc.language | en | |
| dc.rights | http://creativecommons.org/licenses/by-nc-sa/4.0/ | |
| dc.rights | Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) | |
| dc.subject | Matemática | |
| dc.subject | Covering space | |
| dc.subject | Left representation | |
| dc.subject | Pinching operator | |
| dc.subject | Submanifold | |
| dc.subject | Symmetrically-normed ideal | |
| dc.title | Geometry of unitary orbits of pinching operators | |
| dc.type | Articulo | |
| dc.type | Articulo | |
