arXiv subjects

Vladimir V. Kornyak

Publications and source records attributed to Vladimir V. Kornyak.

24 records · Page 2Linked to original sources

arXiv2002

Computation of Cohomology of Lie Algebra of Hamiltonian Vector Fields by Splitting Cochain Complex into Minimal Subcomplexes

Computation of homology or cohomology is intrinsically a problem of high combinatorial complexity. Recently we proposed a new efficient algorithm for computing cohomologies of Lie algebras and superalgebras. This algorithm is based on partition of the full cochain complex into minimal subcomplexes. The algorithm was implemented as a C program LieCohomology. In this paper we present results of applying the program LieCohomology to the algebra of hamiltonian vector fields H(2|0). We demonstrate that the new approach is much more efficient comparing with the straightforward one. In particular, our computation reveals some new cohomological classes for the algebra H(2|0) (and also for the Poisson algebra Po(2|0)).

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arXiv2000

Heat Invariant E_2 for Nonminimal Operator on Manifolds with Torsion

Computer algebra methods are applied to investigation of spectral asymptotics of elliptic differential operators on curved manifolds with torsion and in the presence of a gauge field. In this paper we present complete expressions for the second coefficient (E_2) in the heat kernel expansion for nonminimal operator on manifolds with nonzero torsion. The expressions were computed for general case of manifolds of arbitrary dimension n and also for the most important for E_2 case n=2. The calculations have been carried out on PC with the help of a program written in C.

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arXiv2000

Complete Computation of DeWitt-Seeley-Gilkey Coefficient E_4 for Nonminimal Operator on Curved Manifolds

Asymptotic heat kernel expansion for nonminimal differential operators on curved manifolds in the presence of gauge fields is considered. The complete expressions for the fourth coefficient E_4 in the heat kernel expansion for such operators are presented for the first time. The expressions were computed for general case of manifolds of arbitrary dimension n and also for the most important case n=4. The calculations have been carried out on PC with the help of a program written in C.

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arXiv2000

Computation of Cohomology of Lie Superalgebras of Vector Fields

The cohomology of Lie (super)algebras has many important applications in mathematics and physics. It carries most fundamental ("topological") information about algebra under consideration. At present, because of the need for very tedious algebraic computation, the explicitly computed cohomology for different classes of Lie (super)algebras is known only in a few cases. That is why application of computer algebra methods is important for this problem. We describe here an algorithm and its C implementation for computing the cohomology of Lie algebras and superalgebras. The program can proceed finite-dimensional algebras and infinite-dimensional graded algebras with finite-dimensional homogeneous components. Among the last algebras Lie algebras and superalgebras of formal vector fields are most important. We present some results of computation of cohomology for Lie superalgebras of Buttin vector fields and related algebras. These algebras being super-analogs of Poisson and Hamiltonian algebras have found many applications to modern supersymmetric models of theoretical and mathematical physics.

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arXiv1999

Construction of Involutive Monomial Sets for Different Involutive Divisions

We consider computational and implementation issues for the completion of monomial sets to involution using different involutive divisions. Every of these divisions produces its own completion procedure. For the polynomial case it yields an involutive basis which is a special form of a Groebner basis, generally redundant. We also compare our Mathematica implementation of Janet division to an implementation in C.

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arXiv1999

Cohomology of Lie Superalgebras of Hamiltonian Vector Fields: Computer Analysis

We present the results of computation of cohomology for some Lie (super)algebras of Hamiltonian vector fields and related algebras. At present, the full cohomology rings for these algebras are not known even for the low dimensional vector fields. The partial ``experimental'' results may give some hints for solution of the whole problem. The computations have been carried out with the help of recently written program in C language. Some of the presented results are new.

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