3
votes
1answer
69 views
A terminal coalgebra of a certain functor on Mes
Let $\mathfrak C = \mathsf{Mes}$ be the category of meausurable spaces and measurable maps. For any object $X\in \mathfrak C_0$ we assign a measurable space $\mathcal P(X)$ whose e …
1
vote
3answers
234 views
Why the preimage rather than image in Stone-type dualities.
I am seeking a deeper understanding of the representation of set-based objects in terms of Boolean algebras.
Let $\wp(A)$ be the set of subsets of a set $A$. A relation $R \subset …
5
votes
1answer
170 views
Free cocommutative commutative Hopf monoids
I have some questions about generalizations of abelian groups, relative to symmetric monoidal categories.
1) Let $C$ be a cocomplete cartesian monoidal category with equalizers. I …
3
votes
3answers
984 views
Mistake in Wikipedia Entry “Coalgebra”
Consider the following quote from the Wikipedia entry Coalgebra:
The kernel of every coalgebra morphism $f : C_1 \to C_2$ is a coideal in $C_1$, and the image is a subcoalgebra …
20
votes
7answers
2k views
What is a coalgebra intuitively?
How to think about coalgebras? Are there geometric interpretations of coalgebras?
If I think of algebras and modules as spaces and vectorbundles, what are coalgebras and comodules …
5
votes
2answers
394 views
Primitive elements of a tensor product of bialgebras
Given a field $k$ of characteristic $0$. For every $k$-bialgebra $A$, let $\mathrm{Prim} A$ denote the $k$-vector subspace of $A$ consisting of all primitive elements of $A$.
What …
9
votes
1answer
202 views
Which W*-algebras are the duals of C*-coalgebras?
A Banach algebra (assumed associative and unital) is precisely a monoid object in the monoidal category of Banach spaces, short linear maps, and the projective tensor product. A B …
1
vote
0answers
51 views
Coinduction and corestriction are quasi-inverse equivalences for comodules?
I'm reading http://arxiv.org/abs/math/0310337.
There the following statement is given without proof:
Let $k$ be a field. Let $C$ be a counitary coaugmented coalgebra, i.e. there i …
8
votes
1answer
553 views
Connected graded involutive bialgebras (Hopf algebras) sought (for Dynkin idempotent checking)
Again, there is a general and a concrete question:
Concrete question. Let $H$ be a connected graded bialgebra over a commutative ring $k$ with unity (where graded means $\mathbb N …
6
votes
1answer
303 views
Maps between sets and coalgebras
Hi,
To every set $X$ there corresponds a group-like coalgebra $kX$, with basis $X$. "Grouplike" means that there is a basis $X$ with $\epsilon(x)=1$ and $\Delta(x)=x\otimes x$ for …
1
vote
1answer
214 views
(Co)Universal Property of Quotients/Subs
I'm not completely sure if this bunch of questions is the appropriate Level of MO. However at the same time I think that it is at least slightly above the level of stackex. ...
…
0
votes
0answers
139 views
Coalgebra for a comonad for a really tiny category [closed]
I have a category with only two objects. These objects are just sets, each set has two elements in it. I take the morphisms as all endo-maps of the sets. There are no morphisms …
4
votes
0answers
205 views
Reference for Lie coalgebras needed
In the Wikipeadia article
http://en.wikipedia.org/wiki/Lie_coalgebra
on Lie coalgebras an author said:
"... Just as the exterior algebra of vector fields on a manifold form a Li …
1
vote
1answer
133 views
Linear functional kills all primitives of a connected filtered coalgebra => it lies in m^2?
Let $C$ be a connected filtered coalgebra over a field $k$. Maybe $k$ has characteristic $0$ (though I don't know where this can be of use). Let $1$ denote the unique element of $C …
3
votes
1answer
162 views
Reference for Tensors on graded spaces needed
Is there a good introduction to
1.) Tensor (co)algebras on graded vector spaces ?
2.) Tensor (co)algebras on graded modules ?
In the research field of $L_\infty$-algebras there …

