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 |
33
votes
Accepted
Why is Voevodsky's motivic homotopy theory 'the right' approach?
(Don't be afraid about the word "$\infty$-category" here: they're just a convenient framework to do homotopy theory in).
I'm going to try with a very naive answer, although I'm not sure I understan …
14
votes
Accepted
Is algebraic $K$-theory a motivic spectrum?
Let me assume that $S$ is a regular Noetherian scheme (for example a field). Then algebraic K-theory is a motivic spectrum, and in fact it is represented by the $\mathbb{P}^1$-spectrum that is $BGL_\i …
7
votes
Are there non trivial maps from $H\mathbb{Z}$ to $MGL$?
NO such a map does not exist.
Thanks to Eric Peterson for making me realize that the argument carries through even if the map is not a map of algebras.
By rigidity,you can only consider the case whe …
6
votes
Accepted
Doubt regarding the definition of slice filtration
The key here is that $SH^{eff}(S)$ is closed under suspensions, so there's an inclusion $j_{n+1}:\Sigma^{n+1}_T SH^{eff}(S)\subseteq \Sigma^n_T SH^{eff}(S)$. Hence you can write $i_{n+1}=i_n \circ j_{ …
4
votes
Accepted
Expression of morphisms in motivic homotopy categories in terms of Nisnevich cohomology?
$S^1$-spectra
Let me first show it when the category is $SH^{S^1}(k)$, that is the (∞-)category of $\mathbb{A}^1$-invariant sheaves of spectra. Then the heart of the t-structure is precisely the categ …
3
votes
Dualizability and motivic cohomology
For the equation you are asking about, you don't want $MA$ to be dualizable (which is lucky, because it's not), you want $MA\wedge X_+$ to be dualizable as an $MA$-module. This is true in the situatio …
3
votes
Accepted
Basic question on the cobordism spectrum
A simple way of seeing it is to explicitly spell out what we mean when we say that a spectrum is "presented" by a prespectrum. To say that that a spectrum $E$ is presented by
$$(E_0,E_1,...)$$
means t …
3
votes
Accepted
(Algebraic) cobordism and the rank function
Let me first write what happens for classical cobordism. You are basically asking whether the map $\operatorname{MU}\to H\mathbb{Z}$ factors through the projection $\operatorname{ku}\to H\mathbb{Z}$. …
1
vote
Accepted
Localization, Slice Tower, and Motivic Spectra
The stable motivic category is a presentable symmetric monoidal ∞-category so smashing with any motivic spectrum preserves all homotopy colimits. On the other hand smashing with a spectrum need not to …