Timeline for Ring with three binary operations
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 9, 2015 at 11:28 | comment | added | André Henriques | For $L^2(X)$ to be closed under multiplication, $X$ needs to be discrete. For $L^2(X)$ to be closed under convolution, $X$ needs to be compact. So the only $X$ that work are finite sets (by which I mean finite groups, otherwise, there is no such thing as convolution). | |
| Dec 9, 2015 at 0:07 | comment | added | Michael | @AndréHenriques: or replace $\mathbb R$ with a compact domain. | |
| Dec 8, 2015 at 23:35 | comment | added | André Henriques | $L^2(\mathbb R)$ is not closed under multiplication, and is also not closed under convolution. You should probably use the Schwarz space $\mathit S(\mathbb R)$ instead. | |
| S Dec 8, 2015 at 22:22 | history | answered | Michael | CC BY-SA 3.0 | |
| S Dec 8, 2015 at 22:22 | history | made wiki | Post Made Community Wiki by Michael |