Skip to main content

All Questions

Filter by
Sorted by
Tagged with
13 votes
1 answer
2k views

Roadmap for Algebraic Geometry/Homotopy Theory/Algebraic $K$-Theory intersection

I’m afraid that this is quite a general question but I am hoping some experts can weigh in. I am a student generally interested in learning more about the intersection of algebraic geometry, algebraic ...
Song Ye's user avatar
  • 155
8 votes
0 answers
440 views

Poincaré duality for topological $K$-theory

Let $n$ be an even number. Let $X$ be a $n$-dimensional complex projective manifold with $H^{2m+1}(X,\mathbb{Z})=0$, for all $0\leq m\leq n-1$. $H^{2m}(X,\mathbb{Z})$ is a free $\mathbb{Z}$-module ...
user avatar
4 votes
1 answer
617 views

Computation of KO theory of a point

I have some basic questions about real K-theory (I mean $KO$-theory). Question 1: I have seen the table $$ KO^{-i}(\mathrm{pt})= \begin{cases} \mathbb{Z},& i=0\\ \mathbb{Z}_2,& i=1\\ \mathbb{Z}...
geometricK's user avatar
  • 1,903
0 votes
1 answer
215 views

Computation of the groups $K(BU \times \mathbb{Z})$ and $H^*(BU \times \mathbb{Z})$

Let $U$ denote the limiting group of the chain $U(1) \to U(2) \to U(3) \to \cdots$ I wish to compute the group $K^{-1}\mathbb{C}/\mathbb{Z}(BU \times \mathbb{Z})$. For this, we have the long exact ...
user90041's user avatar
  • 709
80 votes
2 answers
7k views

Vladimir Voevodsky's works

Vladimir Voevodsky has made several contributions in abstract algebraic geometry, focused on the homotopy theory of schemes, algebraic K-theory, and interrelations between algebraic geometry, and ...
12 votes
1 answer
458 views

Algebraic K-theory of a ring

I started to learn some algebraic $K$-theory and its relation to geometric topology problems. My question is: What is the list of rings such that all their algebraic $K$-theory groups are known? I ...
sphere's user avatar
  • 433
6 votes
1 answer
874 views

reference request for mod p and p-adic K-theory

Is there a good reference that explains mod p K-theory and p-adic or p-complete K- theory? All I know about K-theory is the topological K-theory of "vector bundles and k-theory" in Switzer's book (...
usr0192's user avatar
  • 785
11 votes
1 answer
2k views

A survey for various $K$-homology theories and their relationship

The ordinary Topological $K$ theory defined by Atiyah and Hirzebruch is a generalized cohomology theory (see wikipedia).There is the Bott spectrum associated to this generalized cohomology theory....
user2015's user avatar
  • 593
5 votes
1 answer
792 views

$K_0$ of integral group ring of cyclic group $\mathbb{Z}/p\mathbb{Z}$

Is there a table for the computation of $K_0(\mathbb{Z}[\mathbb{Z}/p\mathbb{Z}])$? These groups are also known as ideal class group in number theory.In topology,they are the home of some important ...
user2015's user avatar
  • 593
0 votes
0 answers
369 views

K-theory of $\mathbb{RP}^\infty$

can anyone give some reference of K-theory and K-homology of $\mathbb{RP}^\infty$, both $K_0$ and $K_1$. PS: also posted in stackexchange
jeevan's user avatar
  • 17
1 vote
0 answers
158 views

Is the $K$-Theory of $\mathbb{P}X$ a $\lambda$-Ring?

If we let $\mathbb{P}X$ denote the free commutative algebra generated by the spectrum $X$, then we have a weak equivalence $$ \mathbb{P}X\simeq \bigvee_r E\Sigma_{r+}\wedge_{\Sigma_r}X^{\wedge r}. $$ ...
J126's user avatar
  • 535
4 votes
1 answer
204 views

Yoneda embeddings of stable model categories; composition with Bousfield localizations

For a stable model category $C$ and a set $M$ of object of it I would like to construct a natural functor from $C$ to some stable 'category of functors' on $M$. I suspect that the 'natural' question ...
Mikhail Bondarko's user avatar
4 votes
2 answers
522 views

Equivariant K-theory of $S^1$-action on $S^2$

Is there any references for the structure of the equivariant K-theory $K_{S^1}(S^2)$ where the action of $S^1$ on $S^2$ is defined to be rotation about the $z$-axis? What is the ring structore of $K_{...
Zhaoting Wei's user avatar
  • 9,019
5 votes
1 answer
223 views

What is the role of $\sum (-1)^p[\wedge^pT^*M]$ in the K-theory $K(M)$

I apologize for the vague title. Let $M$ be a compact smooth manifold, then we have $T^*M$ and hence $\wedge^pT^*M$ as vector bundles on $M$. There for we have $$ \sum (-1)^p[\wedge^pT^*M] \in K(M). $...
Zhaoting Wei's user avatar
  • 9,019
9 votes
1 answer
837 views

K-Theory space of finite abelian groups

Consider the abelian category $\mathsf{finAb}$ of finite abelian groups. It is easy to prove that there is an isomorphism $\mathrm{ord} : K_0(\mathsf{finAb}) \to \mathbb{Q}^+$. Can you give a ...
Martin Brandenburg's user avatar
16 votes
2 answers
1k views

Proof of Bott Periodicity in twisted K-theory

I have a question about the Proof of Bott Periodicity in twisted K-theory by Atiyah and Segal in their paper Twisted K-theory. Following their notation, to prove Bott periodicity in this context it ...
José Manuel Gómez's user avatar
36 votes
5 answers
6k views

What is the equivariant cohomology of a group acting on itself by conjugation?

This question makes sense for any topological group $G$, but I'd particularly like to know the answer for $G$ a compact, connected Lie group. $G$ acts on itself by conjugation. One has the equivariant ...
Tim Perutz's user avatar
  • 13.2k