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A. A. Zheltukhin

Publications and source records attributed to A. A. Zheltukhin.

At least 37 records · Page 2Linked to original sources
arXiv2009

Exact solutions for U(1) globally invariant membranes

The exact solvability problem of the nonlinear equations describing the U(1) invariant membranes is studied and the general solution for the static membrane in D=2N+1-dimensional Minkowski space-time, including M-theory case D=11, is obtained. The time-dependent Jacobi elliptic function solution describing a family of contracting tori is also found, together with the solution corresponding to a spinning torus characterized by the presence of the critical rotation frequency Omega=T^{1/3}/pi^{1/2} expressed via the membrane tension T.

hep-th↗
arXiv2007

Unification of twistors and Ramond vectors

We generalize the idea of supertwistors and introduce a new supersymmetric object - the $θ$-twistor which includes the composite Ramond vector [11] well known from the spinning string dynamics. The symmetries of the chiral $θ$-twistor superspace are studied. It is shown that the chiral spin structure introduced by the $θ$-twistor breaks the superconformal boost symmetry but preserves the scale symmetry and the super-Poincare symmetry. This geometrical effect of breaking correlates with the Gross-Wess effect of the conformal boost breaking for bosonic scattering amplitudes.

hep-th↗
arXiv2006

The $θ$-twistor versus the supertwistor

We introduce the $θ$-twistor which is a new supersymmetric generalization of the Penrose twistor and is also alternative to the supertwistor. The $θ$-twistor is a triple of {\it spinors} including the spinor $θ$ extending the Penrose's double of spinors. Using the $θ$-twistors yields an infinite chain of massless higher spin chiral supermultiplets $({1/2},1), (1, {3/2}), ({3/2},2),...,(S, S+{1/2})$ generalizing the known scalar $(0,{1/2})$ supermultiplet

math-ph↗
arXiv2006

A new type of supersymmetric twistors and higher spin chiral multiplets

A new type of supersymmetric twistors is proposed and they are called $θ$-twistors versus the supertwistors. The $θ$-twistor is a triple of spinors including the spinor superspace coordinate $θ$ instead of the Grassmannian scalar in the supertwistor triple. The superspace of the $θ$-twistors is closed under the superconformal group transformations except the (super)conformal boosts. Using the $θ$-twistors in physics preserves the auxiliary field F in the chiral (0,1/2) supermultiplet contrarily to the supertwistor description. Moreover, it yields an infinite chain of higher spin chiral supermultiplets (1/2,1), (1,3/2), (3/2,2),...,(S,S+1/2) generalizing the scalar massless supermultiplet.

hep-th↗
arXiv2005

Supersymmetric Lorentz invariant deformations of superspaces

Lorentz invariant supersymmetric deformations of superspaces based on Moyal star product parametrized by Majorana spinor $λ_{a}$ and Ramond grassmannian vector $ψ_{m}=-{1\over 2}(\barθγ_{m}λ)$ in the spinor realization \cite{VZ} are proposed. The map of supergravity background into composite supercoordinates: $(B^{-1}_{mn}, Ψ^{a}_{m}, C_{ab}) \leftrightarrow (iψ_{m}ψ_{n}, ψ_{m}λ^{a}, λ_{a}λ_{b})$ valid up to the second order corrections in deformation parameter $h$ and transforming the background dependent Lorentz noninvariant (anti)commutators of supercoordinates into their invariant Moyal brackets is revealed. We found one of the deformations to depend on the axial vector $ψ_{1m}={1/2}(\barθγ_{m}γ_{5}λ)$ and to vanish for the $θ$ components with the same chiralities. The deformations in the (super)twistor picture are discussed.

gr-qc↗
arXiv2005

Lorentz invariant supersymmetric mechanism for non(anti)commutative deformations of space-time geometry

A supersymmetric Lorentz invariant mechanism for superspace deformations is proposed. It is based on an extension of superspace by one $λ_{a}$ or several Majorana spinors associated with the Penrose twistor picture. Some examples of Lorentz invariant supersymmetric Poisson and Mojal brackets are constructed and the correspondence: $θ_{mn}\leftrightarrow iψ_{m}ψ_{n},\quad C_{ab}\leftrightarrow λ_{a}λ_{b},\quad Ψ^{a}_{m}\leftrightarrow ψ_{m}λ^{a}$ mapping the brackets depending on the constant background into the Lorentz covariant supersymmetric brackets is established. The correspondence reveals the role of the composite anticommuting vector $ψ_{m}=-{1\over 2}(\barθγ_{m}λ)$ as a covariant measure of space-time coordinate noncommutativity.

hep-th↗
arXiv2005

Quantum BRST charge and OSp(1|8) superalgebra of twistor-like p-branes with exotic supersymmetry and Weyl symmetry

Algebra of the constraints of twistor-like p-branes restoring 3/4 fraction of the spontaneously broken D=4 N=1 supersymmetry is studied using the conversion method. Classical and quantum realizations of the BRST charge, unified superalgebra of the global generalized superconformal OSp(1|8) and Virasoro and Weyl symmetries are constructed. It is shown that the quantum Hermitian BRST charge is nilpotent and the quantized OSp(1|8) superalgebra is closed.

hep-th↗
arXiv2004

Whether conformal supersymmetry is broken by quantum p-branes with exotic supersymmetry?

Classical and quantum symmetries of super $p$-branes preserving exotic 3/4 fraction of $N=1 D=4$ global supersymmetry are studied. Classical realization of the algebra of global and world-volume symmetries is constructed and its quantum generalizations are analyzed. Established is that the status of the conformal supersymmetry $OSp(1|8)$ as a proper quantum symmetry of brane depends both on the choice of its vacuum state and the associated ordering of $\hat{\cal Q}$ and $\hat{\cal P}$ operators.

hep-th↗
arXiv2003

Hamiltonian structure and noncommutativity in $p$-brane models with exotic supersymmetry

The Hamiltonian of the simplest super $p$-brane model preserving 3/4 of the D=4 N=1 supersymmetry in the centrally extended symplectic superspace is derived and its symmetries are described. The constraints of the model are covariantly separated into the first- and the second-class sets and the Dirac brackets (D.B.) are constructed. We show the D.B. noncommutativity of the super $p$-brane coordinates and find the D.B. realization of the $OSp(1|8)$ superalgebra. Established is the coincidence of the D.B. and Poisson bracket realizations of the $OSp(1|8)$ superalgebra on the constraint surface and the absence there of anomaly terms in the commutation relations for the quantized generators of the superalgebra.

hep-th↗
arXiv2003

Wess-Zumino actions and Dirichlet Boundary Conditions for Super p-branes with Exotic Fractions of Supersymmetry

The general solutions in the models of closed and open superstring and super p-branes with exotic fractions of the N=1 supersymmetry are considered and the spontaneously broken character of the $OSp(1,2M)$ symmetry of the models is established. It is shown that extending these models by Wess-Zumino terms generates the Dirichlet boundary conditions for superstring and super p-branes. Using the generalized Wess-Zumino terms new $OSp(1,2M)$ invariant super p-brane and Dp-brane-like actions preserving $\frac{M-1}{M}$ fraction of supersymmetry are proposed. For M=32 these models suggest new superbrane vacua of M-theory preserving 31 from 32 global supersymmetries.

hep-th↗
arXiv2003

Extra Gauge Symmetry for Extra Supersymmetry

It is shown that the extra supersymmetry of tensionless superstring and super $p$-brane is accompanied by the presence of new bosonic gauge symmetries. It permits to use composed coordinates encoding all physical degrees of freedom of the model and invariant under these gauge symmetries and the enhanced $κ$-symmetry. It is proved that the composed gauge invariant coordinates coincide with the componets of symplectic supertwistor realizing a linear representation of the hidden OSp(1,2M) symmetry of the super $p$-brane Lagrangian. A connection of the presented gauge symmetries with massless higher spin gauge theories and a symmetric phase of $M$/string-theory is discussed.

hep-th↗
arXiv2002

An Inverse Penrose Limit and Supersymmetry Enhancement in the Presence of Tensor Central Charges

A connection between weak and strong tension limits and their perturbative corrections is discussed. New twistor-like models based on D=4, N=1 tensionless superstring and superbrane with tensor central charges are studied. The presence of three, two or less preserved fractions of $κ-$symmetry in the actions free of the Wess-Zumino terms is shown. A correlation of extra $κ-$symmetry with the R-symmetry is established. The equations of the superstring and superbrane models preserving 3/4 supersymmetry are exactly solved. The general solution for the Goldstone fermion is pure static, but for the Goldstone bosons it also includes a term describing string/brane motions along the fixed directions given by the initial data. These solutions correspond to the partial spontaneous breaking of the D=4, N=1 global supersymmetry and can be associated with a static closed magnetic Nielsen-Olesen vortex or a p-dimensional vortex.

hep-th↗
arXiv2001

Hamiltonian of Tensionless Strings with Tensor Central Charge Coordinates

A new class of twistor-like string models in four-dimensional space-time extended by the addition of six tensorial central charge (TCC) coordinates $z_{mn}$ is studied. The Hamiltonian of tensionless string in the extended space-time is derived and its symmetries are investigated. We establish that the string constraints reduce the number of independent TCC coordinates $z_{mn}$ to one real effective coordinate which composes an effective 5-dimensional target space together with the $x^{m}$ coordinates. We construct the P.B. algebra of the first class constraints and discover that it coincides with the P.B. algebra of tensionless strings. The Lorentz covariant antisymmetric Dirac $\hat{\mathbf C}$-matrix of the P.B. of the second class constraints is constructed and its algebraic structure is further presented.

hep-th↗
arXiv2001

Strings in a Space with Tensor Central Charge Coordinates

New string models in D=4 space-time extended by tensor central charge coordinates $z_{mn}$ are constructed. We use the $z_{mn}$ coordinates to generate string tension using a minimally extended string action linear in $dz^{mn}$. It is shown that the presence of $z_{mn}$ lifts the light-like character of the tensionless string worldsheet and the degeneracy of its induced metric. We analyse the equations of motion and find a solution of the string equations in the generalized D=(4+6)-dimensional space $X^{\cal M}=(x^{m},z^{mn})$ with $z_{mn}$ describing a spin wave process. A supersymmetric version of the proposed model is formulated.

hep-th↗
arXiv1999

Tensionless strings and the space-time signature change

We construct a tensionless string model in a four-dimensional space-time ${\bf R}^{2,2}$ with the (2,2) signature and solve the string equations. We find that the signature change radically changes the structure of the holonomy group of the null worldsheet. As a result the introduction of the worldsheet Dirac operator invariant under the holonomy group becomes possible. We show that the such possibility is absent in the tensionless string model in the (3+1)-dimensional Minkowski space.

hep-th↗
arXiv1998

Variational principle and a perturbative solution of non-linear string equations in curved space

String dynamics in a curved space-time is studied on the basis of an action functional including a small parameter of rescaled tension $ε=γ/α^{\prime}$, where $γ$ is a metric parametrizing constant. A rescaled slow worldsheet time $T=ετ$ is introduced, and general covariant non-linear string equation are derived. It is shown that in the first order of an $ε$-expansion these equations are reduced to the known equation for geodesic derivation but complemented by a string oscillatory term. These equations are solved for the de Sitter and Friedmann -Robertson-Walker spaces. The primary string constraints are found to be split into a chain of perturbative constraints and their conservation and consistency are proved. It is established that in the proposed realization of the perturbative approach the string dynamics in the de Sitter space is stable for a large Hubble constant $H (α^{\prime}H^{2}\gg1)$.

hep-th↗
arXiv1996

On a Possibility of Membrane Cosmology

Tensionless null p-branes in arbitrary cosmological backgrounds are considered and their motion equations are solved. It is shown that an ideal fluid of null p-branes may be considered as a source of gravity for D-dimensional Friedmann- Robertson-Walker universes.

hep-th↗