6,391 reputation
1625
bio website poisson.phc.unipi.it/~mossa
location Earth
age 26
visits member for 3 years, 5 months
seen 14 hours ago

I'm math student, in particular I'm interested in algebra, geometry, topology and category theory (especially higher dimensional category theory) and its application in mathematics.


May
19
answered Tensor product of a vector space and a field
May
19
revised What's the significance of defining group as a group object in category $\mathcal{Set}$?
added stuff
May
19
answered What's the significance of defining group as a group object in category $\mathcal{Set}$?
May
16
answered Quotient modules isomorphic $ \Rightarrow$ submodules isomorphic
May
14
answered Doubt about Yoneda Embedding as image of the hom functor
May
13
answered question about $p$-Sylow subgroups
May
13
revised Unit for Left Adjoint to the Inclusion Functor
Fixed some typos (functor $i$ cannot be composed with object of the category $\mathbf{Set}/I$)
May
13
answered Clarification about the definition of term algebras
May
12
comment Ultrafilter Lemma and Dimension Theorem
@AsafKaragila Ah, ok thanks. For me the dimension theorem was the one stating the existance of a basis... guess I was wrong :)
May
12
comment Ultrafilter Lemma and Dimension Theorem
I belive there's a mistake: the dimension theorem for arbitrary vector spaces is equivalent to the axioms of choice while, as you stated above, the ultrafilter lemma is not.
May
10
comment Homotopy equivalence between $X/A$ and $X$?
Touche, my bad ... Too work and sleep make Giorgio a dull boy.
May
10
comment Homotopy equivalence between $X/A$ and $X$?
This is a very well known theorem, you can find it every book of algebraic topology, for instance in Hatcher Algebraic Topology.
May
7
answered Make ring in natural way
May
6
comment Showing that every map $f : S^2 \rightarrow S^1$ is homotopic to the trivial map
@user125103 yes your proof is correct.
May
6
answered Showing that every map $f : S^2 \rightarrow S^1$ is homotopic to the trivial map
May
5
answered What are well-defined functions?
May
4
answered Can you give me some concrete examples of magmas?
May
4
comment Natural transformation is a mono iff the components are.
@magma I see that probably I should have made clear my intent from the beginning. I've edited the answer, is it ok now?
May
4
revised Natural transformation is a mono iff the components are.
Added some specifications
May
4
comment Natural transformation is a mono iff the components are.
I wanted to emphatize the fact that is one of the two implications that require the functors to be $\mathbf{Set}$-valued, while the other holds in the generic case.