arXiv subjects

Salem Omri

Publications and source records attributed to Salem Omri.

6 recordsLinked to original sources

arXiv2024

On the third cohomology of the Lie algebra of vector fields on weighted densities on R

Let Vect($\mathbb{R}$) be the Lie algebra of smooth vector fields on $\mathbb{R}$ and $\mathbb{F}_λ$ be the space of $λ$-densities on $\mathbb{R}$. Vect($\mathbb{R}$) acts on $\mathbb{F}_λ$ by Lie derivative. In this paper, we compute the third differential cohomology of the Lie algebra Vect($\mathbb{R}$) with coeffcients in the space $\mathbb{F}_λ.$ Explicit cocycles spanning these cohomology spaces are given.

math.RA↗

arXiv2018

The Binary $\mathfrak{aff}(n|1)$-Invariant Differential Operators On Weighted Densities On The Superspace $\mathbb{R}^{1|n}$ And $\mathfrak{aff}(n|1)$-Relative Cohomology

We consider the $\mathfrak{aff}(n|1)-$module structure on the spaces of differential bilinear operators acting on the superspaces of weighted densities. We classify $\mathfrak{aff}(n|1)-$invariant binary differential operators acting on the spaces of weighted densities. This result allows us to compute the first $\mathfrak{aff}(n|1)-$relative differential cohomology of $\mathcal{K}(n)$ with coefficients in the superspace of linear differential operators acting on the superspaces of weighted densities.

math.DG↗

arXiv2009

The Binary Invariant Differential Operators on Weighted Densities on the superspace $\mathbb{R}^{1|n}$ and Cohomology

Over the $(1,n)$-dimensional real superspace, $n>1$, we classify $\mathcal{K}(n)$-invariant binary differential operators acting on the superspaces of weighted densities, where $\mathcal{K}(n)$ is the Lie superalgebra of contact vector fields. This result allows us to compute the first differential cohomology of %the Lie superalgebra $\mathcal{K}(n)$ with coefficients in the superspace of linear differential operators acting on the superspaces of weighted densities--a superisation of a result by Feigin and Fuchs. We explicitly give 1-cocycles spanning these cohomology spaces.

math.RT↗

arXiv2009

Deformation of Vect($\mathbb{R})$-Modules of Symbols

We consider the action of the Lie algebra of polynomial vector fields, $\mathfrak{vect}(1)$, by the Lie derivative on the space of symbols $\mathcal{S}_δ^n=\bigoplus_{j=0}^n \mathcal{F}_{δ-j}$. We study deformations of this action. We exhibit explicit expressions of some 2-cocycles generating the second cohomology space $\mathrm{H}^2_{\rm diff}(\mathfrak{vect}(1),{\cal D}_{ν,μ})$ where ${\cal D}_{ν,μ}$ is the space of differential operators from $\mathcal{F}_ν$ to $\mathcal{F}_μ$. Necessary second-order integrability conditions of any infinitesimal deformations of $\mathcal{S}_δ^n$ are given. We describe completely the formal deformations for some spaces $\mathcal{S}_δ^n$ and we give concrete examples of non trivial deformations.

math.RT↗

arXiv2006

Deforming the Lie Superalgebra of Contact Vector Fields on $S^{1|1}$

We classify nontrivial deformations of the standard embedding of the Lie superalgebra K(1) of contact vector fields on the (1,1)-dimensional supercircle into the Lie superalgebra of superpseudodifferential operators on the supercircle. This approach leads to the deformations of the central charge induced on K(1) by the canonical central extension of $SΨDO$.

math-ph↗

arXiv2006

On the Cohomology of the Lie Superalgebra of Contact Vector Fields on $S^{1|2}$

We investigate the first cohomology space associated with the embedding of the Lie superalgebra $\cK(2)$ of contact vector fields on the (1,2)-dimensional supercircle $S^{1\mid 2}$ in the Lie superalgebra $\cSΨ\cD \cO(S^{1\mid 2})$ of superpseudodifferential operators with smooth coefficients. Following Ovsienko and Roger, we show that this space is ten-dimensional with only even cocycles and we give explicit expressions of the basis cocycles.

math-ph↗