bio | website | math.stanford.edu/~church |
---|---|---|
location | Stanford | |
age | ||
visits | member for | 5 years, 9 months |
seen | Jul 29 at 21:06 | |
stats | profile views | 4,233 |
Jul 17 |
comment |
The evaluation fibration of a transitive, effective topological group action
Do you mean "fibration" or "fiber bundle"? en.wikipedia.org/wiki/Fibration en.wikipedia.org/wiki/Fiber_bundle |
Jul 17 |
comment |
Properties of loop space functor from homotopy types to group objects in homotopy types
I'm not an expert in any of this material, but it seems to me that it might be helpful to learn about classifying spaces before jumping to $(\infty,1)$-categories. |
Jul 17 |
comment |
When to postpone a proof?
Your Example 1 is dragging this discussion in the wrong direction, since everyone is going to agree with it: who would object to stating the main theorems in the introduction? The real question is about the structure of arguments within the body of the paper, and when it is appropriate to postpone a proof there. This is an important question, which too many authors neglect to think about when outlining their papers; I hope we'll get to hear a discussion on this point. |
Jul 13 |
reviewed | Approve Why is the fundamental group of a compact Riemann surface not free ? |
May 27 |
reviewed | Approve The possibility of a symmetric difference in a torsion-free group |
May 24 |
comment |
Searching for $C^*$
This is clearly a question of interest to research mathematicians (indeed uniquely to research mathematicians). |
May 21 |
comment |
Will this be a case of self plagiarism or will it annoy the referee?
I'm voting to close this question as off-topic because it belongs on academia.stackexchange.com (and was also asked there: academia.stackexchange.com/questions/45754/…) |
May 16 |
comment |
Generalize $\pi_0(B\mathcal{C})\cong\{\text{objects}\}/\{\text{morphisms}\}$ to categories internal to topological spaces
The proof you give is not correct. Consider the category $x\rightarrow y\leftarrow z$. There is a path in $B\mathcal{C}$ from $x$ to $z$, but there is no morphism in $\mathcal{C}$ from $x$ to $z$. This contradicts your claim "which means that there is a morphism between x0 and x1"; the mistake seems to be in the earlier claim "yields a path ... but as $N_1(\mathcal{C}) is discrete, it is constant". As Zhen Lin points out, the correct deduction is that there is a zigzag of morphisms from $x_0$ to $x_1$. |
Apr 29 |
comment |
Continuous maps to fat geometric realizations of simplicial spaces
Note there is a typo in the statement of Segal's Proposition 4.1: it should say that $\text{pr}\colon BX_U\to X$ is a homotopy equivalence, not $BR_U\to X$. |
Apr 28 |
awarded | Revival |
Mar 25 |
reviewed | Approve Can an abelian variety/Q have no non-trivial points over Q_sol? |
Mar 24 |
reviewed | Approve Mal'cev “rational equivalence” and model theory |
Mar 18 |
reviewed | Approve hyperbolic metrics |
Mar 15 |
answered | Does there exist a fibre bundle $K(\mathbb{Z}_4,1)\rightarrow K(\mathbb{Z}_2,1)$ with fiber $K(\mathbb{Z}_2,1)$? |
Mar 6 |
answered | Maryam Mirzakhani's works |
Mar 6 |
reviewed | Approve latex tag wiki |
Feb 26 |
comment |
$G_\mathbb{Z}$-homotopy type of rational Tits building $\Delta_{G, \mathbb{Q}}$
@J.Martel: We're considering the usual cellular homology of these buildings with integer coefficients, without interference from any groups at all. |
Feb 26 |
revised |
$G_\mathbb{Z}$-homotopy type of rational Tits building $\Delta_{G, \mathbb{Q}}$
add reference to paper arXiv:1501.01307, now that it is posted |
Feb 26 |
reviewed | Approve matrix-theory tag wiki excerpt |
Feb 24 |
awarded | Excavator |