Timeline for Continuity of the derivations from semisimple Banach algebras
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 9, 2019 at 17:58 | comment | added | Fermat | Thank you Yemon Choi and Robert Israel for your valuable comments and also for giving the references. | |
| Mar 9, 2019 at 17:56 | vote | accept | Fermat | ||
| Feb 25, 2019 at 18:50 | answer | added | Tomasz Kania | timeline score: 4 | |
| Feb 25, 2019 at 1:26 | comment | added | Yemon Choi | Alternatively, it is an exercise in the book of Allan (ed. Dales) that there are discontinuous derivations from $C^n[0,1]$ into one-dimensional bimodules when $n\geq 1$: see this other MO question mathoverflow.net/questions/319859/… | |
| Feb 25, 2019 at 1:24 | comment | added | Yemon Choi | Assumng ZFC, Dales has "constructed" (in the 1970s) an example of a discontinuous derivation from the disc algebra to a suitable target bimodule. The construction is supposed to be in doi.org/10.1112/plms/s3-27.4.638 but I currently don't have access to the article to check. One place you can try to find more information is the later article of Jewell: dx.doi.org/10.2140/pjm.1977.71.465 | |
| Feb 24, 2019 at 20:36 | comment | added | Robert Israel | It is consistent with ZF (without Axiom of Choice) that there are no discontinuous linear operators from a Banach space to a normed space. So you're not going to get any "explicit" counterexamples. | |
| Feb 24, 2019 at 18:32 | history | edited | Fermat | CC BY-SA 4.0 |
added 2 characters in body
|
| Feb 24, 2019 at 18:27 | history | asked | Fermat | CC BY-SA 4.0 |