bio | website | math.stanford.edu/~church |
---|---|---|
location | Stanford | |
age | ||
visits | member for | 5 years, 8 months |
seen | 9 hours ago | |
stats | profile views | 4,181 |
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 |
Feb 24 |
revised |
Example of a Group which has $\text{SL}_{n}(\mathbb{Z})$ as the automorphism group
added Oliver Baues to author list (and added links to arXiv, MathReviews and journal) |
Feb 3 |
reviewed | Leave Open Is there any Lefschetz-like principle for representations of finite groups? |
Feb 3 |
reviewed | Leave Open Direct product of filters |
Feb 3 |
reviewed | Leave Open Propositional logic: Minimal set of formulas, which is consistent and complete |