arXiv subjects

Igor V. Shirokov

Publications and source records attributed to Igor V. Shirokov.

5 recordsLinked to original sources

arXiv2020

Classification of scalar second-order differential equations with low-dimensional symmetry groups: The case of free action

Based on an original classification of differential equations by types of regular Lie group actions, we offer a systematic procedure for describing partial differential equations with prescribed symmetry groups. Using a new powerful algebraic technique based on the so-called covariant form of a differential equation, we give an effective algorithm for constructing differential equations whose symmetry groups regularly and freely act on the space of dependent and independent variables. As an application, we derive a complete classification of quasi-linear scalar second-order partial differential equations with regular free symmetry groups of dimension no greater than three.

math-ph↗

arXiv2017

Algebraic method for construction of infinitesimal invariants of Lie groups representations

We propose the method for obtaining invariants of arbitrary representations of Lie groups that reduces this problem to known problems of linear algebra. The basis of this method is the idea of a special extension of the representation space, which allows us to regard it as a coalgebra of some Lie algebra. In its turn, this allows us to reduce the problem of constructing invariants of a given representation to the problem of constructing invariants of the coadjoint representation of the corresponding Lie group. In our previous paper it was shown that this problem can always be solved in a natural way by the methods of linear algebra.

math.RT↗

arXiv2015

Computation of Composition Functions and Invariant Vector Fields in Terms of Structure Constants of Associated Lie Algebras

Methods of construction of the composition function, left- and right-invariant vector fields and differential 1-forms of a Lie group from the structure constants of the associated Lie algebra are proposed. It is shown that in the second canonical coordinates these problems are reduced to the matrix inversions and matrix exponentiations, and the composition function can be represented in quadratures. Moreover, it is proven that the transition function from the first canonical coordinates to the second canonical coordinates can be found by quadratures.

math-ph↗

arXiv2015

A method of integration for classical and quantum equations based on the connection between canonical transformations and irreducible representations of Lie groups

We propose a method for integrating the right-invariant geodesic flows on Lie groups based on the use of a special canonical transformation in the cotangent bundle of the group. We also describe an original method of constructing exact solutions for the Klein - Gordon equation on unimodular Lie groups. Finally, we formulate a theorem which establishes a connection between the special canonical transformation and irreducible representations of Lie group. This connection allows us to consider the proposed methods of integrating for classical and quantum equations in the framework of a unified approach.

math-ph↗

arXiv2011

Integrable magnetic geodesic flows on Lie groups

Right-invariant geodesic flows on manifolds of Lie groups associated with 2-cocycles of corresponding Lie algebras are discussed. Algebra of integrals of motion for magnetic geodesic flows is considered and necessary and sufficient condition of integrability in quadratures is formulated. Canonic forms for 2-cocycles of all 4-dimensional Lie algebras are given and integrable cases among them are separated.

math-ph↗