arXiv subjects
Publications and source records attributed to Theodore Voronov.
We give a complete description of differential operators generating a given bracket. In particular we consider the case of Jacobi-type identities for odd operators and brackets. This is related with homotopy algebras using the derived bracket construction. (Based on a talk at XXII Workshop on Geometric Methods in Physics at Bialowieza)
We give a necessary and sufficient condition for the existence of a local solution of the inverse problem of calculus of variations in terms of the identical vanishing of the variation of a functional on an extended space (with the number of independent variables increased by one), and explain its relation with the classical Helmholtz criterion using the de Rham complex on an infinite-dimensional space of fields.
We analyze geometry of the second order differential operators, having in mind applications to Batalin--Vilkovisky formalism in quantum field theory. As we show, an exhaustive picture can be obtained by considering pencils of differential operators acting on densities of all weights simultaneously. The algebra of densities, which we introduce here, has a natural invariant scalar product. Using it, we prove that there is a one-to-one correspondence between second-order operators in this algebra and the corresponding brackets. A bracket on densities incorporates a bracket on functions, an ``upper connection'' in the bundle of volume forms, and a term similar to the ``Brans--Dicke field'' of the Kaluza--Klein formalism. These results are valid for even operators on a usual manifold as well as for odd operators on a supermanifold. For an odd operator $Δ$ we show that conditions on the order of the operator $Δ^2$ give an hierarchy of properties such as flatness of the upper connection and the Batalin--Vilkovisky master equation. In particular, we obtain a complete description of generating operators for an arbitrary odd Poisson bracket.
We solve the following problem: to describe in geometric terms all differential operators of the second order with a given principal symbol. Initially the operators act on scalar functions. Operator pencils acting on densities of arbitrary weights appear naturally in the course of study. We show that for the algebra of densities it is possible to establish a one-to-one correspondence between operators and brackets generated by them. Everything is applicable to supermanifolds as well as to usual manifolds. In the super case the problem is closely connected with the geometry of the Batalin--Vilkovisky formalism in quantum field theory, namely the description of the generating operators for an odd bracket. We give a complete answer. This text is a concise outline of the main results. A detailed exposition is in \texttt{arXiv:math.DG/0212311}.
We define \textit{graded manifolds} as a version of supermanifolds endowed with an additional $\mathbb Z$-grading in the structure sheaf, called \textit{weight} (not linked with parity). Examples are ordinary supermanifolds, vector bundles over supermanifolds, double vector bundles, iterated constructions like $TTM$, etc. I give a construction of \textit{doubles} for \textit{graded} $QS$- and \textit{graded $QP$-manifolds} (graded manifolds endowed with a homological vector field and a Schouten/Poisson bracket). Relation is explained with Drinfeld's Lie bialgebras and their doubles. Graded $QS$-manifolds can be considered, roughly, as ``generalized Lie bialgebroids''. The double for them is closely related with the analog of Drinfeld's double for Lie bialgebroids recently suggested by Roytenberg. Lie bialgebroids as a generalization of Lie bialgebras, over some base manifold, were defined by Mackenzie and P. Xu. Graded $QP$-manifolds give an {odd version} for all this, in particular, they contain ``odd analogs'' for Lie bialgebras, Manin triples, and Drinfeld's double.
We consider odd Laplace operators acting on densities of various weight on an odd Poisson (= Schouten) manifold $M$. We prove that the case of densities of weight 1/2 (half-densities) is distinguished by the existence of a unique odd Laplace operator depending only on a point of an ``orbit space'' of volume forms. This includes earlier results for odd symplectic case, where there is a canonical odd Laplacian on half-densities. The space of volume forms on $M$ is partitioned into orbits by a natural groupoid whose arrows correspond to the solutions of the quantum Batalin--Vilkovisky equations. We give a comparison with the situation for Riemannian and even Poisson manifolds. In particular, the square of odd Laplace operator happens to be a Poisson vector field defining an analog of Weinstein's ``modular class''.
We consider the variational complex on infinite jet space and the complex of variational derivatives for Lagrangians of multidimensional paths and study relations between them. The discussion of the variational (bi)complex is set up in terms of a flat connection in the jet bundle. We extend it to supercase using a particular new class of forms. We establish relation of the complex of variational derivatives and the variational complex. Certain calculus of Lagrangians of multidimensional paths is developed. It is shown how covariant Lagrangians of higher order can be used to represent characteristic classes.
The complex of "stable forms" on supermanifolds is studied. Stable forms on $M$ are represented by certain Lagrangians of "copaths" (formal systems of equations, which may or may not specify actual surfaces) on $M\times\mathbb R^D$. Changes of $D$ give rise to stability isomorphisms. The Cartan--de Rham complex made of stable forms extends both in positive and negative degree and its positive half is isomorphic to the complex of forms defined as Lagrangians of paths. Considering the negative half is necessary, in particular, for homotopy invariance. We introduce analogs of exterior multiplication by covectors and of contraction with vectors. We find (anti)commutation relations for them. An analog of Cartan's homotopy identity is proved. Before stabilization it contains some "stability operator" $σ$.
We consider the following construction of quantization. For a Riemannian manifold $M$ the space of forms on $T^*M$ is made into a space of (full) symbols of operators acting on forms on $M$. This gives rise to the composition of symbols, which is a deformation of the (``super'')commutative multiplication of forms. The symbol calculus is exact for differential operators and the symbols that are polynomial in momenta. We calculate the symbols of natural Laplacians. (Some nice Weitzenböck like identities appear here.) Formulas for the traces corresponding to natural gradings of $Ω(T^*M)$ are established. Using these formulas, we give a simple direct proof of the Gauss-Bonnet-Chern Theorem. We discuss these results in the connection of a general question of the quantization of forms on a Poisson manifold.
We prove that an analog of the exterior differential acts on the space of arbitrary Lagrangians of multidimensional paths on any manifold or supermanifold, thus making this space into a cochain complex. An analog of the Stokes' formula holds. The construction and the proofs are purely geometrical, in terms of the variation of corresponding actions.
We define generalized bialgebras and Hopf algebras and on this basis we introduce quantum categories and quantum groupoids. The quantization of the category of linear (super)spaces is constructed. We establish a criterion for the classical value of the dimension of the polynomial function algebra on the full subcategory of this quantum category specified by Sudbery type commutation relations for quantum vector spaces (the ``Poincare -- Birkhoff -- Witt property''). The criterion is the equality of the ``quantum constants'' $c_\a=c_\b^{\pm 1}$ of the quantum vector spaces. (These constants appeared in earlier works on PBW for the multiparameter quantization of the general linear group.) Links with the Yang-Baxter equation and the Yang -- Baxter structures of quantum linear spaces are established. The role of categories as a generalization of groups is discussed.
We investigate forms on supermanifolds defined as Lagrangians of ``copaths'' (that is, systems of equations, which may or may not specify submanifolds). For this, we consider direct products $M^{n|m}\times\Bbb R^{r|s}$ and study isomorphisms corresponding to simultaneously advancing the number of additional parameters $r|s$ and the number of equations. We define an exteriour differential in terms of variational derivatives w.r.t. a copath and establish its main properties. In the resulting stable picture we obtain infinite complexes $\D:\Om{r}{s}\to\Om{r+1}{s}$ for $M^{n|m}$, where $0 \le s \le m$ and $r$ can be any integer. For $r\ge 0$ a canonical isomorphism with forms constructed as Lagrangians of $r|s$-paths is established. We discover the ``lacking half'' of forms on supermanifolds: $r|s$-forms with $r<0$, previously unknown except for $s=m$. (They have been partly replaced earlier by an augmentation of the ``non-negative'' part of the complexes.) All these results are new. The study of these questions is in progress now.