arXiv subjects

A. Sorin

Publications and source records attributed to A. Sorin.

28 records · Page 2Linked to original sources

arXiv1995

Conformal Linearization Versus Nonlinearity of $W$-Algebras

We review the new approach to the theory of nonlinear $W$-algebras which is developed recently and called {\it conformal linearization}. In this approach $W$-algebras are embedded as subalgebras into some {\it linear conformal} algebras with a finite set of currents and most of their properties could be understood in a much simpler way by studing their linear counterpart. The general construction is illustrated by the examples of $u(N)$-superconformal, $W(sl(N),sl(2))$, $W(sl(N),sl(N))$ as well as $W(sl(N),sl(3))$ algebras. Applications to the construction of realizations (included modulo null fields realizations) as well as central charge spectrum for minimal models of nonlinear algebras are discussed. (To appear in ``Geometry and Integrable Models'', Eds.: P.N.Pyatov & S.N.Solodukhin, World Scientific Publ. Co. (in press)).

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arXiv1995

Null Fields Realizations of $W_3$ from $W(sl(4),sl(3))$ and $W(sl(3|1),sl(3))$ Algebras

We consider the nonlinear algebras $W(sl(4),sl(3))$ and $W(sl(3|1),sl(3))$ and find their realizations in terms of currents spanning conformal linearizing algebras. The specific structure of these algebras, allows us to construct realizations modulo null fields of the $W_3$ algebra that lies in the cosets $W(sl(4),sl(3))/u(1)$ and $W(sl(3|1),sl(3))/u(1)$. Such realizations exist for the following values of the $W_3$ algebra central charge: $c_W=-30,-40/7,-98/5,-2$. The first two values are listed for the first time, whereas for the remaining values we get the new realizations in terms of an arbitrary stress tensor and $u(1)\times sl(2)$ affine currents.

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arXiv1995

$N=2$ Super-$W_3^{(2)}$ Algebra in Superfields

We present a manifestly $N=2$ supersymmetric formulation of $N=2$ super-$W_3^{(2)}$ algebra (its classical version) in terms of the spin 1 unconstrained supercurrent generating a $N=2$ superconformal subalgebra and the spins 1/2, 2 bosonic and spins 1/2, 2 fermionic constrained supercurrents. We consider a superfield reduction of $N=2$ super-$W_3^{(2)}$ to $N=2$ super-$W_3$ and construct a family of evolution equations for which $N=2$ super-$W_3^{(2)}$ provides the second hamiltonian structure.

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arXiv1995

On the Super-NLS Equation and its Relation with N=2 Super-KdV within Coset Approach

A manifestly $N=2$ supersymmetric coset formalism is introduced to describe integrable hierarchies. It is applied to analyze the super-NLS equation. It possesses an $N=2$ symmetry since it can be obtained from a manifest $N=2$ coset algebra construction. A remarkable result is here discussed: the existence of a Bäcklund transformation which connects the super-NLS equation to the equations belonging to the integrable hierarchy of one particular (the $a=4$) $N=2$ super-KdV equation. $N=2$ scalar Lax pair operators are introduced for both super-KdV and super-NLS.

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arXiv1995

THE MINIMAL N=2 SUPEREXTENSION OF THE NLS EQUATION

We show that the well known $N=1$ NLS equation possesses $N=2$ supersymmetry and thus it is actually the $N=2$ NLS equation. This supersymmetry is hidden in terms of the commonly used $N=1$ superfields but it becomes manifest after passing to the $N=2$ ones. In terms of the new defined variables the second Hamiltonian structure of the supersymmetric NLS equation coincides with the $N=2$ superconformal algebra and the $N=2$ NLS equation belongs to the $N=2$ $a=4$ KdV hierarchy. We propose the KP-like Lax operator in terms of the $N=2$ superfields which reproduces all the conserved currents for the corresponding hierarchy.

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arXiv1995

MORE ON THE LINEARIZATION OF $W$-ALGEBRAS

We show that a wide class of $W$-(super)algebras, including $W_N^{(N-1)}$, $U(N)$-superconformal as well as $W_N$ nonlinear algebras, can be linearized by embedding them as subalgebras into some {\em linear} (super)conformal algebras with finite sets of currents. The general construction is illustrated by the example of $W_4$ algebra.

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arXiv1995

The Full Structure of Quantum $N=2$ Super-$W_3^{(2)}$ Algebra

We present the complete structure of the nonlinear $N=2$ super extension of Polyakov-Bershadsky, $W_3^{(2)}$, algebra with the generic central charge, $c$, at the {\it quantum} level. It contains extra two pairs of fermionic currents with integer spins 1 and 2, besides the currents of $N=2$ superconformal and $W_3^{(2)}$ algebras. For $c\rightarrow \infty$ limit, the algebra reduces to the classical one, which has been studied previously. The 'hybrid' field realization of this algebra is also discussed.

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arXiv1994

Linearizing $W_{2,4}$ and $WB_2$ Algebras

It has recently been shown that the $W_3$ and $W_3^{(2)}$ algebras can be considered as subalgebras in some linear conformal algebras. In this paper we show that the nonlinear algebras $W_{2,4}$ and $WB_2$ as well as Zamolodchikov's spin $5/2$ superalgebra also can be embedded as subalgebras into some linear conformal algebras with a finite set of currents. These linear algebras give rise to new realizations of the nonlinear algebras which could be suitable in the construction of $W$-string theories.

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arXiv1994

Linearizing W-Algebras

We show that the Zamolodchikov's and Polyakov-Bershadsky nonlinear algebras $W_3$ and $W_3^{(2)}$ can be embedded as subalgebras into some {\em linear} algebras with finite set of currents. Using these linear algebras we find new field realizations of $W_3^{(2)}$ and $W_3$ which could be a starting point for constructing new versions of $W$-string theories. We also reveal a number of hidden relationships between $W_3$ and $W_3^{(2)}$. We conjecture that similar linear algebras can exist for other $W$-algebras as well.

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arXiv1994

The $N=2$ Super-$W_3^{(2)}$ Algebra

We construct the nonlinear $N=2$ super-$W_3^{(2)}$ algebra with an arbitrary central charge at the classical level in the framework of Polyakov "soldering" procedure. It contains two non-intersecting subalgebras: $N=2$ superconformal algebra and $W_3^{(2)}$ and their closure gives the $N=2$ super-$W_3^{(2)}$ algebra. Besides the currents of $N=2$ superconformal and $W_3^{(2)}$ algebras, it comprises two pairs of fermionic currents with spins 1 and 2. The hybrid field realization and contractions to the zero central charge are constructed.

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