A Generalization of Ando's Theorem and Parrott's Example
| dc.creator | Opela, David | |
| dc.date | 2005-05-09 | |
| dc.date.accessioned | 2026-07-07T05:19:43Z | |
| dc.date.available | 2026-07-07T05:19:43Z | |
| dc.description | Ando's theorem states that any pair of commuting contractions on a Hilbert space can be dilated to a pair of commuting unitaries. Parrott presented an example showing that an analogous result does not hold for a triple of pairwise commuting contractions. We generalize both of these results as follows. Any n-tuple of contractions that commute according to a graph without a cycle can be dilated to an n-tuple of unitaries that commute according to that graph. Conversely, if the graph contains a cycle, we construct a counterexample. | |
| dc.description | 6 pages, accepted in PAMS | |
| dc.identifier | https://arxiv.org/abs/math/0505154 | |
| dc.identifier | http://arxiv.org/abs/math/0505154 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/75123 | |
| dc.subject | Operator Algebras | |
| dc.subject | Functional Analysis | |
| dc.subject | 47A20 | |
| dc.title | A Generalization of Ando's Theorem and Parrott's Example | |
| dc.type | text |