Timeline for Almost but not quite a homomorphism
Current License: CC BY-SA 2.5
21 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 8, 2018 at 9:54 | answer | added | T.H. | timeline score: 2 | |
| Aug 12, 2018 at 0:41 | answer | added | Somatic Custard | timeline score: 0 | |
| Feb 10, 2010 at 9:07 | comment | added | Adam Libster | Vipul - I just want to say that I love the group properties wiki and I use it all the time! | |
| Feb 9, 2010 at 22:48 | answer | added | user1835 | timeline score: 0 | |
| Feb 9, 2010 at 18:12 | comment | added | Vipul Naik | @Henry: You're right, I'm sorry the question wasn't explicit. In any case, even though quasimorphisms weren't the kind of thing I was initially interested in, I think they could be of interest to many people, so I appreciate Qiachu Yuan's comment. I'm sorry about the confusion I created. | |
| Feb 9, 2010 at 18:09 | history | edited | Vipul Naik | CC BY-SA 2.5 |
added 543 characters in body
|
| Feb 9, 2010 at 17:54 | answer | added | MTS | timeline score: -1 | |
| Feb 9, 2010 at 17:39 | answer | added | faridrb | timeline score: 4 | |
| Feb 9, 2010 at 17:34 | answer | added | Gerhard Paseman | timeline score: 0 | |
| Feb 9, 2010 at 17:05 | comment | added | HJRW | Yemon, yes, I think so too, but the question isn't explicit. One just has to infer that from the examples that he gives. He hasn't defined the 'framework' that he refers to above. Oh, I give up. | |
| Feb 9, 2010 at 11:41 | answer | added | Yemon Choi | timeline score: 1 | |
| Feb 9, 2010 at 11:21 | comment | added | Yemon Choi | @Henry: I think Vipul wants these near-HMs to take values in more general groups. In particular, what about near-automorphisms? | |
| Feb 9, 2010 at 11:15 | answer | added | Boris Bukh | timeline score: 5 | |
| Feb 8, 2010 at 23:39 | comment | added | HJRW | Vipul,in that case, you need to explain your context further in the question. As it stands, it seems to me that quasimorphisms would be a very good answer. | |
| Feb 8, 2010 at 22:25 | comment | added | Vipul Naik | You're right, it's sort of like that, but the distinguishing feature is that there is a fixed "target", so the notion of composition doesn't make sense. I think it is something in the nature of a "norm". It just so happened that I was interested in things that can be composed end to end to form a new category. | |
| Feb 8, 2010 at 21:17 | comment | added | HJRW | I meant multiplicative group, of course. | |
| Feb 8, 2010 at 21:16 | comment | added | HJRW | Vipul, I don't understand your objection. A quasimorphism is by definition a map f:G->R such that |f(gh)-f(g)-f(h)| is bounded for all g,h. In other words, it's 'almost' a homomorphism from G to the additive group of R. | |
| Feb 8, 2010 at 20:52 | answer | added | Andrew Stacey | timeline score: 0 | |
| Feb 8, 2010 at 20:13 | comment | added | Vipul Naik | That concept of quasimorphism, and its application, are very interesting! But I don't think that the framework I have here matches that concept, because it is a map to the real numbers. (Alas, the word "quasi-()-morphism" is overloaded). | |
| Feb 8, 2010 at 19:56 | comment | added | Qiaochu Yuan | My understanding is that geometric group theorists use "quasimorphisms" a lot: lamington.wordpress.com/2009/06/04/quasimorphisms-and-laws | |
| Feb 8, 2010 at 19:53 | history | asked | Vipul Naik | CC BY-SA 2.5 |