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V. Yu. Ovsienko

Publications and source records attributed to V. Yu. Ovsienko.

5 recordsLinked to original sources

Cohomology of the vector fields Lie algebra and modules of differential operators on a smooth manifold

Let $M$ be a smooth manifold, $\cal S$ the space of polynomial on fibers functions on $T^*M$ (i.e., of symmetric contravariant tensor fields). We compute the first cohomology space of the Lie algebra, $Vect(M)$, of vector fields on $M$ with coefficients in the space of linear differential operators on $\cal S$. This cohomology space is closely related to the $Vect(M)$-modules, ${\cal D}_λ(M)$, of linear differential operators on the space of tensor densities on $M$ of degree $λ$.

math.DG

Projectively equivariant symbol calculus

The spaces of linear differential operators on ${\mathbb{R}}^n$ acting on tensor densities of degree $λ$ and the space of functions on $T^*{\mathbb{R}}^n$ which are polynomial on the fibers are not isomorphic as modules over the Lie algebra $\Vect({\mathbb{R}}^n)$ of vector fields on ${\mathbb{R}}^n$. However, these modules are isomorphic as $sl(n+1,{\mathbb{R}})$-modules where $sl(n+1,{\mathbb{R}})\subset \Vect({\mathbb{R}}^n)$ is the Lie algebra of infinitesimal projective transformations. In addition, such an $sl_{n+1}$-equivariant bijection is unique (up to normalization). This leads to a notion of projectively equivariant quantization and symbol calculus for a manifold endowed with a (flat) projective structure. We apply the $sl_{n+1}$-equivariant symbol map to study the $\Vect(M)$-modules of linear differential operators acting on tensor densities, for an arbitrary manifold $M$.

math.DG

Projectively invariant symbol map and cohomology of vector fields Lie algebras intervening in quantization

We define the unique (up to normalization) symbol map from the space of linear differential operators on $R^n$ to the space of polynomial on fibers functions on $T^* R^n$, equivariant with respect to the Lie algebra of projective transformations $sl_{n+1}\subset\Vect(R^n)$. We apply the constructed $sl_{n+1}$-invariant symbol to studying of the natural one-parameter family of $\Vect(M)$-modules on the space of linear differential operators on an arbitrary manifold M. Each of the $\Vect(M)$-action from this family can be interpreted as a deformation of the standard $\Vect(M)$-module $S(M)$ of symmetric contravariant tensor fields on M. We define (and calculatein the case: $M= R^n$) the corresponding cohomology of $\Vect(M)$ related with this deformation. This cohomology realize the obstruction for existence of equivariant symbol and quantization maps. The projective Lie algebra $sl_{n+1}$ naturally appears as the algebra of symmetries on which the involved $\Vect(M)$-cohomology is trivial.

dg-ga

Theorem on six vertices of a plane curve via the Sturm theory

We discuss the theorem on the existence of six points on a convex closed plane curve in which the curve has a contact of order six with the osculating conic. (This is the ``projective version'' of the well known four vertices theorem for a curve in the Euclidean plane.) We obtain this classical fact as a corollary of some general Sturm-type theorems.

dg-ga

Structures Symplectiques sur les Espaces de Courbes Projectives et Affines

A symplectic structure on the space of nondegenerate and nonparametrized curves in a locally affine manifold is defined. We also consider several interesting spaces of nondegenerate projective curves endowed with Poisson structures. This construction connects the Virasoro algebra and the Gel'fand-Dikii bracket with the projective differential geometry.

hep-th