6,110 reputation
12178
bio website sas.upenn.edu/~vnanda
location Philadelphia, PA
age
visits member for 2 years, 11 months
seen 1 hour ago

Currently a post-doc at UPenn, was a graduate student at Rutgers. Author of the Perseus Morse-theoretic computational homology software.


21h
reviewed Approve suggested edit on Failure of Fredholm property of elliptic PDE systems
1d
comment Reference request: Book of topology from “Topos” point of view
Welcome to MO! $~~~$
Aug
29
awarded  Popular Question
Aug
26
comment Brouwer fixed points via flow
Picard-Lindelof and its analogues only guarantee the existence of solutions locally.
Aug
25
reviewed Approve suggested edit on What does the defect of a block measure?
Aug
24
reviewed Reject suggested edit on Who named it the Snake Lemma?
Aug
24
reviewed Approve suggested edit on Metric on the set of subsets of the rational primes
Aug
21
revised Are there “chain complexes” and “homology groups” taking values in pairs of topological spaces?
Removed old update.
Aug
14
comment Zigzags and contractibility of categories
@OmarAntolín-Camarena Yes, sorry about that. And thanks for the helpful comments which brought the question to its present form.
Aug
14
comment In a fibration, can a deformation retraction of the base be lifted to the total space?
It seems as though the OP is asking precisely for those "mild conditions" that you've mentioned in your answer.
Aug
14
answered Simplicial complices on unlabelled vertices
Aug
14
accepted Zigzags and contractibility of categories
Aug
14
revised Zigzags and contractibility of categories
added 136 characters in body
Aug
14
revised Zigzags and contractibility of categories
modified in light of comments
Aug
13
comment Zigzags and contractibility of categories
Dear @Fedotov, I understand. So if the coherent nerve of the hammock localization has an initial element, can we then conclude that the original category is contractible as well? And does the localization functor induce a homotopy equivalence on classifying spaces in this case?
Aug
13
comment Zigzags and contractibility of categories
@ZhenLin certainly I don't mean to use this for anything like $\mathbf{Set}$. But tons of examples can be generated by taking various copies of $x \to x_0 \gets x_1 \cdots$ and gluing them all at $x$ for instance. The category so obtained does not have an initial object, but the zigzag category contracts to $x$.
Aug
13
asked Zigzags and contractibility of categories
Aug
11
reviewed Approve suggested edit on Convex hull of total orders
Aug
11
accepted When is the determinant a Morse function?
Aug
2
comment Does every compact manifold exhibit an almost global chart
@MatthiasWendt It doesn't look like a smooth structure is being assumed on $M$.