9
votes
1answer
129 views
Links which HOMFLY homology distinguish but the HOMFLY polynomial does not.
Does anyone know of a pair of different links which the HOMFLY polynomial does not distinguish, but HOMFLY homology does? Or does there exist such a pair of links?
I'm assumi …
0
votes
0answers
128 views
polynomial representation of $sl_{2}(k)$
Let $k$ be an algebraic closed field of characteristic 0. We write
$$X=\left(
\begin{array}{ccc}
0 & 1\\
0 & 0\\
\end{array}
\right),~~
Y=\left(
\begin{array}{ccc}
0 & …
1
vote
2answers
83 views
Existence of a projection operator onto a classical set of density matrices
I have a Hilbert space of quantum density matrices written in the Glauber-Sudarshan P representation - ie. we have coherent states $|\alpha \rangle$ and we write density matrices a …
0
votes
0answers
88 views
When does the rank of a module behave sub-multiplicatively under tensoring?
Let $\cal{E}$ be a finitely generated projective bimodule over a (noncommutative) algebra $A$. Moreover, let us assume that $\cal{E}$ is of finite rank $n$. The tensor product
$
…
9
votes
1answer
156 views
How unique are extensions of TQFTs to lower dimension?
Say I have an "ordinary" TQFT $F$ of dimension $n$, assigning groups or vector spaces to closed $(n-1)$-manifolds and linear maps to cobordisms. Consider the different ways $F$ can …
0
votes
1answer
58 views
Decomposition of C' Kazhdan-Lusztig basis element associated to longest word in S_n
I'm trying to decompose the Kazhdan-Lusztig C' basis element associated to the longest word in $S_n$, $C'_{w_0}$ into products and sums of elements $C'_w$ where $w < w_0$ in the …
16
votes
2answers
292 views
A direct proof of the Harer-Zagier recursion enumerating the ways to paste a 2n-gon to get a genus g surface?
In a 1986 paper, Harer and Zagier proved the recursion:
$$(n+1)e(g,n)=(4n-2)e(g,n-1)+(2n-1)(n-1)(2n-3)e(g-1,n-2)$$
where e(g,n) is the number of ways of grouping sides $S_1...S_{ …
8
votes
1answer
300 views
Quantum-Jimbo Algebras: Why Such Fuss About Roots of Unity?
Coming from a Lie algebraic background, I'm trying to branch onto quantum group theory. The divide I see all the time, is $q$ a root of unity or $q$ not a root of unity. I am wonde …
1
vote
1answer
100 views
Hopf Duals and Matrix Coefficients
One defines the finite dual of a Hopf algebra $A$ as
$$
H^o := {f \in H^* ~|~ f(I) = 0, \text{ for some ideal $I$ of $H$ with } \dim_C(H/I) < \infty }.
$$
As is well-known, $H …
3
votes
0answers
173 views
Quantum Coordinate Algebras at Roots of Unity and Non-Standard Irrep Types
Let $\frak{g}$ be a complex semi-simple Lie algebra of rank $n$, and $U_q(\frak{g})$ the corresponding Drinfeld-Jimbo algebra. As is well-known, for $q$ not a root of unity, the ir …
4
votes
2answers
171 views
Quantized Enveloping Algebras at $q=1$
As is well-known, the quantized enveloping algebra $U_q(\frak{sl}_2)$ is not well-defined when $q=1$ because of the relation
$$
[E,F] = \frac{K-K^{-1}}{q-q^{-1}}.
$$
To address thi …
0
votes
0answers
64 views
A list of infinite dimensional coalgebras over a field
I'm looking for a vast list of infinite list of coalgebras of infinite dimension, I'm familiar with the standard ones, any example is well received. I'm currently writing a paper o …
4
votes
2answers
183 views
$q$-Deforming Woronowicz’s Leibniz Rule
The Woronowicz definition of a differential calculus over an algebra consists of a pair $(\Omega,$d$)$, where $\Omega$ is an $A-A$-bimodule, and
$$
\text{d}:A \to \Omega,
$$
is a …
4
votes
4answers
214 views
Non-Drinfeld--Jimbo Deformations and Finite Quantum Groups
As is well-known, for the compact semi-simple Lie groups $G$, there exist non-commutative Hopf algebra deformations ${\cal O}_q[G]$ of their coordinate algebras ${\cal O}[G]$, the …
1
vote
1answer
58 views
Generators of the Quantum Coordinate Algebras and Quantized Enveloping Algebra Representations
The representations of the quantized enveloping algebra $U_q(\frak{sl}_n)$ are labeled by the positive weight lattice $P^+$ of the classical Lie algebra $\frak{sl}_n$. Moreover, th …

