User Spice the Bird

21 votes

3 answers

2k views

If $X$ is a simplicial complex, is there a characterization of the links of its vertices that is equivalent to the statement "$|X|$ is a manifold"?

asked Dec 13, 2012 at 18:19

17 votes

2 answers

1k views

What is the homotopy type of the space of the homeomorphisms of the n-ball whose restriction to the boundary is isotopic to the identity?

asked Nov 7, 2012 at 5:34

13 votes

5 answers

1k views

Is the following invariant of rooted trees a complete invariant?

asked Sep 22, 2012 at 20:45

11 votes

1 answer

496 views

What is the precise relationship between "prodsimplicial sets" and rooted trees?

asked May 23, 2012 at 4:14

6 votes

4 answers

2k views

What is the intuition of connections for cubical sets?

asked Nov 27, 2011 at 3:00

5 votes

2 answers

739 views

A subcategory of top where subspaces and subobjects coincide?

asked Jun 22, 2011 at 20:52

5 votes

0 answers

162 views

What propositions about sets can be transfered to propositions about a presheaf category?

asked Mar 7, 2012 at 2:12

4 votes

2 answers

403 views

Is it possible to define the notion of a localization of a category without reference to a set of morphisms, $S$?

asked Apr 6, 2012 at 5:48

3 votes

1 answer

325 views

Does each "prod-simplicial" regular cell complex come from a unique rooted tree?

asked Sep 6, 2012 at 13:29

3 votes

3 answers

383 views

Are the categories, $\widehat{\mathcal{A}}\downarrow X$ and $\widehat{\mathcal{A}\downarrow X}$ equivalent.

asked Apr 8, 2011 at 1:51

3 votes

1 answer

503 views

What is the chromatic number of the graph whose vertices dimension $n-2$ subsimplicies of $\Delta^n$ and an edge between two vertices is given if the two associated $n-2$ vertices are contained in the same $n-1$ subsimplex?

asked Jan 29, 2012 at 23:02

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11 Questions

If $X$ is a simplicial complex, is there a characterization of the links of its vertices that is equivalent to the statement "$|X|$ is a manifold"?

What is the homotopy type of the space of the homeomorphisms of the n-ball whose restriction to the boundary is isotopic to the identity?

Is the following invariant of rooted trees a complete invariant?

What is the precise relationship between "prodsimplicial sets" and rooted trees?

What is the intuition of connections for cubical sets?

A subcategory of top where subspaces and subobjects coincide?

What propositions about sets can be transfered to propositions about a presheaf category?

Is it possible to define the notion of a localization of a category without reference to a set of morphisms, $S$?

Does each "prod-simplicial" regular cell complex come from a unique rooted tree?

Are the categories, $\widehat{\mathcal{A}}\downarrow X$ and $\widehat{\mathcal{A}\downarrow X}$ equivalent.

What is the chromatic number of the graph whose vertices dimension $n-2$ subsimplicies of $\Delta^n$ and an edge between two vertices is given if the two associated $n-2$ vertices are contained in the same $n-1$ subsimplex?