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5 votes
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125 views

Lie algebra cohomology of formal non-commutative vector fields

Let $k$ be a field of characteristic $0$ and $A=k\langle\langle x_1,\dotsc,x_n\rangle\rangle$ be a free completed associative algebra. The space of continuous derivations $\mathrm{Der}(A)$ is ...
Qwert Otto's user avatar
5 votes
0 answers
164 views

Generalized commutator

A well-known generalization of the commutator for operators is the so-called q-commutator defined as $$[A,B]_q=AB-qBA.$$ I was wondering if the case where $q$ is not a number but other operator has ...
Nicolas Medina Sanchez's user avatar
4 votes
0 answers
112 views

Restricted universal extensions and lifting of derivations

Let $L$ be a perfect Lie algebra. Then it is well-known that $L$ has a universal central extension $\hat{L}$ and every derivation of $L$ can be lifted to a derivation of $\hat{L}$. (See e.g. Section 2 ...
Salvatore Siciliano's user avatar
4 votes
1 answer
148 views

First adjoint cohomology space of simple Lie algebras

Let $L$ be a central extension of a simple Lie algebra $\mathfrak{g}$ such that $L=[L,L]$. It is not difficult to see that if $H^1(\mathfrak{g}, \mathfrak{g})=0$ then $H^1(L,L)=0$. In other words, if ...
Salvatore Siciliano's user avatar
2 votes
0 answers
115 views

Lie derivations of algebra of smooth functions in a symplectic manifold

Let $(M,\omega)$ be a finite-dimensional symplectic manifold. The algebra $C^\infty(M)$ of smooth functions is a Poisson algebra. Derivations $D : C^\infty(M) \to C^\infty(M)$ of the Poisson ...
José Figueroa-O'Farrill's user avatar