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visits | member for | 1 year, 9 months |
seen | 10 hours ago | |
stats | profile views | 397 |
Aug 23 |
comment |
Semidirect products with braid groups and type $F_\infty$
Nice trick! Why don't you post it as a regular answer so that I can upvote and accept it? Question too easy? |
Aug 22 |
revised |
Semidirect products with braid groups and type $F_\infty$
deleted 34 characters in body |
Aug 22 |
comment |
Semidirect products with braid groups and type $F_\infty$
By permutation of the factors via the projection $B_k\rightarrow S_k$. |
Aug 22 |
asked | Semidirect products with braid groups and type $F_\infty$ |
Aug 20 |
comment |
Directed subposet of a poset containing the minimal elements
Thanks Paul for the keywords, I will have to look them up. I used the definition of E in the context of arxiv.org/abs/1407.5171 Definition 6.3. But I have the feeling that there is more behind that definition and that's why I'm asking. |
Aug 17 |
revised |
Directed subposet of a poset containing the minimal elements
added 60 characters in body |
Aug 17 |
revised |
Directed subposet of a poset containing the minimal elements
added 115 characters in body |
Aug 17 |
comment |
Directed subposet of a poset containing the minimal elements
Andreas, yes, there might be no minimal elements in $\{z:x<z>y\}$ and this set even might be empty. However, in my application, there is always at least one minimal element in that set. |
Aug 17 |
asked | Directed subposet of a poset containing the minimal elements |
Jul 2 |
awarded | Curious |
May 2 |
accepted | Isomorphisms and higher homotopy |
May 2 |
asked | Isomorphisms and higher homotopy |
May 1 |
accepted | When are automorphisms in categories homotopically trivial? |
May 1 |
comment |
When are automorphisms in categories homotopically trivial?
Ah, $\gamma$ is still absorbed by $\theta$ (and therefore by $\phi$). Thanks for the example. Btw, the order of the arrows was better before your edit. Path concatenation usually is written from left to right. I always prefer to write $ab$ instead of $b\circ a$ in private so that I don't get confused all day. ;) |
May 1 |
comment |
When are automorphisms in categories homotopically trivial?
Thanks for the answer. Could you tell me why $\delta$ is null-homotopic? Maybe I'm just blind. |
May 1 |
asked | When are automorphisms in categories homotopically trivial? |
Mar 30 |
accepted | Reducing the simplices in the nerve of a category with an object with trivial endomorphism monoid |
Mar 25 |
comment |
Reducing the simplices in the nerve of a category with an object with trivial endomorphism monoid
Could you give me a reference for this? |
Mar 24 |
comment |
Reducing the simplices in the nerve of a category with an object with trivial endomorphism monoid
As pointed out by მამუკაჯიბლაძე, the arrow $b\rightarrow f$ closes the circle in the full subcategory where $a$ is not present, it is also a $S^1$. |
Mar 24 |
accepted | Pushout of categories along embeddings gives homotopy pushout? |