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at.algebraictopology
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 2group 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 Einfinity 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 Einfinity 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 Einfinity operad
Not everybody would consider the BarrattEccles operad to be Einfinity. 
Jan
31 
comment 
Reference request for a “truncated version” of the de Rham algebra
Also in differential Ktheory 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? 