Timeline for Are there other semidirect product/crossed products in other areas
Current License: CC BY-SA 3.0
12 events
| when toggle format | what | by | license | comment | |
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| Apr 4, 2017 at 14:22 | vote | accept | Chris Ramsey | ||
| Mar 25, 2017 at 17:09 | answer | added | Qiaochu Yuan | timeline score: 11 | |
| Mar 24, 2017 at 14:03 | answer | added | Mark Grant | timeline score: 5 | |
| Mar 24, 2017 at 12:35 | comment | added | Benjamin Steinberg | It depends if you view the collection as its coproduct | |
| Mar 23, 2017 at 23:02 | answer | added | Konstantinos Kanakoglou | timeline score: 16 | |
| Mar 23, 2017 at 20:31 | comment | added | მამუკა ჯიბლაძე | @BenjaminSteinberg Strictly speaking, not on a category but on a bunch of categories :D | |
| Mar 23, 2017 at 20:30 | comment | added | მამუკა ჯიბლაძე | A fairly general semidirect product notion exists in semiabelian categories, see the paper by Bourn and Janelidze "Protomodularity, Descent and Semidirect Products" in TAC (1998). Basically, it works for those varieties of algebras where surjective homomorphisms have identifiable element inverses; then any split surjective homomorphism can be described as a semidirect product. This includes groups, Lie algebras, associative algebras (with an algebra with unit acting on another one without unit via bimultiplications), and many more. | |
| Mar 23, 2017 at 19:15 | history | edited | YCor |
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| Mar 23, 2017 at 19:14 | comment | added | YCor | Semidirect product of Lie algebras (one being endowed with an action by derivation on the other). | |
| Mar 23, 2017 at 19:06 | comment | added | Gerhard Paseman | There are wreath products for other algebraic structures. Joel Vanderwerf did his dissertation under John Rhodes on this. Gerhard "If You Ignore Function Signature" Paseman, 2017.03.23. | |
| Mar 23, 2017 at 19:02 | comment | added | Benjamin Steinberg | You can do grothendieck construction when a category acts on a category. | |
| Mar 23, 2017 at 18:58 | history | asked | Chris Ramsey | CC BY-SA 3.0 |