Search Results
Search type | Search syntax |
---|---|
Tags | [tag] |
Exact | "words here" |
Author |
user:1234 user:me (yours) |
Score |
score:3 (3+) score:0 (none) |
Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
Views | views:250 |
Code | code:"if (foo != bar)" |
Sections |
title:apples body:"apples oranges" |
URL | url:"*.example.com" |
Saves | in:saves |
Status |
closed:yes duplicate:no migrated:no wiki:no |
Types |
is:question is:answer |
Exclude |
-[tag] -apples |
For more details on advanced search visit our help page |
A branch of algebraic topology concerning the study of cocycles and coboundaries. It is in some sense a dual theory to homology theory. This tag can be further specialized by using it in conjunction with the tags group-cohomology, etale-cohomology, sheaf-cohomology, galois-cohomology, lie-algebra-cohomology, motivic-cohomology, equivariant-cohomology, ...
13
votes
2
answers
891
views
References for Stiefel-Whitney class of Stiefel manifolds and Grassmannians
Let $M$ be a manifold. The total Stiefel-Whitney class of $M$ is defined to be the Stiefel-Whitney class of the tangent bundle $TM$
$$
w(M)=1+w_1(TM)+w_2(TM)+\cdots
$$
I want to find references for
$$ …
12
votes
1
answer
822
views
Stiefel-Whitney class of fibre bundles
Or even in terms of the cohomology ring
$$
H^*(B;\mathbb{Z}_2), H^*(F;\mathbb{Z}_2)
$$
And other factors? …
10
votes
2
answers
1k
views
cup product and Steenrod operations in Serre spectral sequence
Suppose all differentials in the cohomology Serre spectral sequence (corresponding to the above fibration) are zero maps. … .
$$
Question 1: as cohomology rings with cup products, do we still have the isomorphism
$$
H^*(E)\cong H^*(F)\otimes H^*(B)? …
10
votes
1
answer
1k
views
positions of a methane molecule with carbon atom at the origin
Question: as a manifold, what is the cohomology ring (with cup product)
$$
H^*(G;\mathbb{Z}_2)
$$
and the Steenrod square $Sq$'s acting on the cohomology ring? …
9
votes
1
answer
484
views
Steenrod operations on cohomology of grassmannians
Their cohomology rings are expressed in terms of universal Stiefel-Whitney classes
$$
H^*(G_k(\mathbb{R}^\infty);\mathbb{Z}_2)=\mathbb{Z}_2[w_1,w_2,\cdots,w_k],$$
$$
H^*(G_k(\mathbb{R}^n);\mathbb{Z}_2) … =\mathbb{Z}_2[w_1,w_2,\cdots,w_k]/(\bar w_{n-k+1},\bar w_{n-k+2}\cdots,\bar w_n).$$
What are the Steenrod operations $Sq^i$ on these cohomology rings? …
9
votes
4
answers
1k
views
Examples of Stiefel-Whitney classes of manifolds
Let $M$ by an compact, connected $n$-dimensional manifold without boundary.
Are there any other computable examples of the Stiefel-Whitney class $w(M)$ except for $M=S^m, \mathbb{R}P^m,\mathbb{C}P^m, …
8
votes
1
answer
931
views
cohomology of iterated loop space on spheres
Question: Are there any references where I can find the explicit expression of the cohomology algebra
$$
H^*(\Omega^nS^n;\mathbb{Z}_2)? …
8
votes
2
answers
1k
views
rational cohomology of finite real grassmannian
Then according to Theorem 1.6, The Cohomology of BSO n and BO n with Integer Coefficients, Proceedings of the American Mathematical Society 1982 Vol 85-2, Edgar H.Brown JR.,
$H^*(G_n(\mathbb{R}^\infty …
7
votes
0
answers
192
views
mod $p$ homology module of unordered configuration spaces of the projective plane
Let $M$ be a manifold and $k$ be a positive integer. Let $F(M,k)$ be the $k$-th ordered configuration space over $M$, consisting of all ordered $k$-tuples of distinct points in $M$. Let $\Sigma_k$ be …
5
votes
0
answers
148
views
configuration space of Riemannian manifolds with a parameter on the distance of distinct points
Question: are there any references for the cohomology ring
$$
H^*(B(M,k,\epsilon);\mathbb{Z}_2)?
$$ …
4
votes
1
answer
243
views
group completion theorem of homology as Hopf algebras
Let $M$ be a topological monoid with product $\mu$. Then $H_*(M)$ is a Hopf algebra with product $\mu_*$ and coproduct $\Delta_*$. The group-completion theorem by McDuff-Segal, 1976 gives that as a P …
4
votes
1
answer
250
views
Configuration spaces of positive and negative particles
.
$$
Question: Could the theorem 1.1 be strengthened to the statement that for some $k$,
$$
(\alpha_k)^*: H^*(\Gamma_k(M;S^0))\to H^*(F(M,k)/\Sigma_k)
$$
is a ring isomorphism of cohomology rings? …
3
votes
2
answers
318
views
cohomology algebra of braid spaces, configuration spaces
Cohen, Lecture Notes in Mathematics, Vol. 533, Chapter 5, 6, 7, 8, 9, 10, 11, the cohomology algebra $H^*(B(\mathbb{R}^{n+1},p),\mathbb{Z}_p)$, for $p$ prime and $B(\mathbb{R}^{n+1},p)=F(\mathbb{R}^{n … For other manifolds $M$ such as $S^m$ and $S^m\times \mathbb{R}^k$ ($H^*F(\mathbb{R}^{n+1},p;\mathbb{Z}_p)$ is known in these cases), are there any results for the cohomology algebra $H^*(B(M,p);\mathbb …
3
votes
1
answer
196
views
group completion theorem by using homology fibrations
In the paper Homology fibrations and group completion theorem, McDuff-Segal (www.maths.ed.ac.uk/~aar/papers/mcdsegal.pdf), page 281:
Let $M$ be a topological monoid such that $\pi_0M$ is generated by …
3
votes
2
answers
595
views
mod p cohomology ring of alternating groups
What is the cohomology ring
$$
H^*(A_4;\mathbb{Z}/3)
$$
and its Steenrod operation $P^i$'s?
(2). … Are there general results about the cohomology ring
$$
H^*(A_{p+1};\mathbb{Z}/p)
$$
for general primes $p\geq 3$?
(3). …