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7h
reviewed Approve $V(A)$ semi group of equivalent projections in $M_∞(A)$ cancelative?
1d
reviewed Close Is it possible to write down the explicit expressions of some extensions of conformal vector fields on spheres?
1d
comment How to construct a free 2-group on a groupoid?
Ronnie I think that this notion of freeness is unrelated to the notion Tom is asking about.
Feb
8
reviewed Approve Closed subgroups of GL(n)
Feb
8
reviewed Approve What is a foliation and why should I care?
Feb
7
comment The fibration map $Diff(M) \rightarrow Emb(N,M)$
I don't think you're asking whether a particular map is a fibration
Feb
7
comment Definition of E-infinity operad
I don't know any model structure on operads where BE is cofibrant. I'd love to know of one if it happens to exist.
Feb
6
comment DG natural transformation Serre functors
This is getting too crazy.
Feb
5
comment DG natural transformation Serre functors
The derived tensor product with a representing cycle does the job.
Feb
5
comment Definition of E-infinity operad
I just meant it's not cofibrant, which is required by some authors.
Feb
5
comment Is the bar construction of a CDGA model a Hopf algebra model for the loop space?
We have a problem at the very beginning. Rational cochains do not form a CDGA. With Sullivan models everything works as expected, assuming usual finiteness and connectivity conditions.
Feb
5
comment Reference for generalized model categories
Since you know the main reference, use now mathscinet or Google.
Feb
4
comment Is this additive equivalence a triangulated equivalence?
You're welcome. The same example answers your new question in the negative.
Feb
4
comment References about the matrix generators of the finite subgroups of the orthogonal group O(4)
@YCor since the quesiton mentions matrices,I think it's on explicit representations rather than generators.
Feb
2
comment Is there a general way to define invariants in a category, using generalized elements?
Don't you consider that Yoneda's lemma answers your question?
Feb
2
answered Is this additive equivalence a triangulated equivalence?
Feb
1
comment Definition of E-infinity operad
Not everybody would consider the Barratt-Eccles operad to be E-infinity.
Jan
31
comment Reference request for a “truncated version” of the de Rham algebra
Also in differential K-theory and more general differential cohomology theories.
Jan
31
comment Reference request for a “truncated version” of the de Rham algebra
I don't think anything is wrong. I think I don't really understand the question. In homological algebra, this kind of quotient is pretty common. It is called truncation in a $t$-structure. In this case you're considering the canonical $t$-structure in a derived category and you're truncating not a plain complex but an algebra object.
Jan
31
comment Reference request for a “truncated version” of the de Rham algebra
Isn't it a plain quotient?