11,665 reputation
1245
bio website
location
age
visits member for 3 years, 6 months
seen Apr 2 at 23:29

Oct
31
comment Geometric interpretation of integrals of coordinate rings
How are your Hopf algebras related to a manifold ?
Oct
20
awarded  Yearling
Aug
4
awarded  Nice Question
Jun
25
awarded  ac.commutative-algebra
Jun
25
awarded  at.algebraic-topology
Jun
25
awarded  gr.group-theory
Jun
25
awarded  group-cohomology
Jun
25
awarded  homological-algebra
Jun
25
awarded  Revival
Jun
3
comment transgression in terms of cup product in case of non-trivial action of the group on the coeffecients module
Yes, it's OK. Thank you Mark.
May
31
answered transgression in terms of cup product in case of non-trivial action of the group on the coeffecients module
May
30
comment On avoiding a linear subspace of an algebra
What is a linear form in this context ? Is it just a homogeneous element ?
May
29
revised Is there an $A$ such that $B$ injective iff 1st Ext functor vanishes?
added 188 characters in body; deleted 4 characters in body
May
29
answered Is there an $A$ such that $B$ injective iff 1st Ext functor vanishes?
May
29
awarded  Enlightened
May
29
awarded  Nice Answer
May
29
comment dual of Z^I for uncountable I
To address the question in the title: The $\mathbb{Z}$-dual of $\mathbb{Z}^I$ is the free abelian group whose rank equals the cardinality of the set $D$ of all countably complete ultrafilters on $I$. Moreover, $|I| \le |D|$ and if the cardinality of $I$ is less than the first measurable cardinal, then $|I|=|D|$. For references see my answer to this question: mathoverflow.net/questions/132073/…
May
29
revised Homomorphisms from powers of Z to Z
Incorporated Andreas Blass' comments
May
28
comment transgression in terms of cup product in case of non-trivial action of the group on the coeffecients module
Is the upper $G/H$ in $H^{p-1}(...)^{G/H}$ correct ?
May
28
comment Homomorphisms from powers of Z to Z
... direct product. This may also be the reason why the title of their paper includes the words "non-commutative". In particular, they refer to the Eklof-Mekler book for generalizations of the Specker phenomenon on uncountable direct products (p. 420, before Def. 2.1). To summarize: 1. The isomorphism in my 1st comment is correct (reference: Eklof-Mekler, Cor. III.3.7). 2. $\phi$ is an isomorphism if $I$ is not $\omega$-measurable (references in my answer).