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Valeriy N. Tolstoy

Publications and source records attributed to Valeriy N. Tolstoy.

5 recordsLinked to original sources

Drinfeldians

We construct two-parameter deformation of an universal enveloping algebra $U(g[u])$ of a polynomial loop algebra $g[u]$, where $g$ is a finite-dimensional complex simple Lie algebra (or superalgebra). This new quantum Hopf algebra called the Drinfeldian $D_{qη}(g)$ can be considered as a quantization of $U(g[u])$ in the direction of a classical r-matrix which is a sum of the simple rational and trigonometric r-matrices. The Drinfeldian $D_{qη}(g)$ contains $U_{q}(g)$ as a Hopf subalgebra, moreover $U_{q}(g[u])$ and $Y_η(g)$ are its limit quantum algebras when the $D_{qη}(g)$ deformation parameters $η$ goes to 0 and $q$ goes to 1, respectively. These results are easy generalized to a supercase, i.e. when $g$ is a finite-dimensional contragredient simple superalgebra.

math.QA↗

Two-parameter deformation of loop algebras and superalgebras

We discuss two-parameter deformations of an universal enveloping algebra $U(g[u])$ of a polynomial loop algebra $g[u]$, where $g$ is a finite-dimensional complex simple Lie algebra (or superalgebra). These deformations are Hopf algebras. One deformation called Drinfeldian is a quantization of $U(g[u])$ in the direction of a classical r-matrix which is a sum of the simplest rational and trigonometric r-matrices. Another deformation (discussed only for the case $g=sl_{2}$) is a twisting of the usual Yangian $Y_η(sl_{2})$.

q-alg↗

Yangian Double and Rational R-matrix

Studying the algebraic structure of the double ${\cal D}Y(g)$ of the yangian $Y(g)$ we present the triangular decomposition of ${\cal D}Y(g)$ and a factorization for the canonical pairing of the yangian with its dual inside ${\cal D}Y(g)$. As a consequence we obtain an explicit formula for the universal R-matrix $R$ of ${\cal D}Y(g)$ and demonstrate how it works in evaluation representations of $Y(sl_2)$. We interprete one-dimensional factor arising in concrete representations of $R$ as bilinear form on highest weight polynomials of irreducible representations of $Y(g)$ and express this form in terms of {\it gamma-functions}.

hep-th↗

Representation Theory of Quantized Poincare Algebra. Tensor Operators and Their Application to One-Partical Systems

A representation theory of the quantized Poincaré ($κ$-Poincaré) algebra (QPA) is developed. We show that the representations of this algebra are closely connected with the representations of the non-deformed Poincaré algebra. A theory of tensor operators for QPA is considered in detail. Necessary and sufficient conditions are found in order for scalars to be invariants. Covariant components of the four-momenta and the Pauli-Lubanski vector are explicitly constructed.These results are used for the construction of some q-relativistic equations. The Wigner-Eckart theorem for QPA is proven.

hep-th↗

Twisting of quantum (super)algebras. Connection of Drinfeld's and Cartan-Weyl realizations for quantum affine algebras

We show that some factors of the universal R-matrix generate a family of twistings for the standard Hopf structure of any quantized contragredient Lie (super)algebra of finite growth. As an application we prove that any two isomorphic superalgebras with different Cartan matrices have isomorphic q-deformations (as associative superalgebras) and their standard comultiplications are connected by such twisting. We present also an explicit relation between the generators of the second Drinfeld's realization and Cartan-Weyl generators of quantized affine nontwisted Kac-Moody algebras. Further development of the theory of quantum Cartan-Weyl basis, closely related with this isomorphism, is discussed. We show that Drinfeld's formulas of a comultiplication for the second realization are a twisting of the standard comultiplication by factors of the universal R-matrix. Finally, properties of the Drinfeld's comultiplication are considered.

hep-th↗