23 research outputs found
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
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
to one real effective coordinate which composes an effective
5-dimensional target space together with the 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 -matrix of the P.B. of the second class
constraints is constructed and its algebraic structure is further presented.Comment: 18 pages, Latex, no figure
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 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 invariant super p-brane
and Dp-brane-like actions preserving fraction of supersymmetry
are proposed. For M=32 these models suggest new superbrane vacua of M-theory
preserving 31 from 32 global supersymmetries.Comment: Latex, 13 page
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
, where is a metric parametrizing
constant. A rescaled slow worldsheet time is introduced, and
general covariant non-linear string equation are derived.
It is shown that in the first order of an -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 .Comment: 22 pages, LATEX, no figure
Type IIB tensionless superstrings in a pp-wave background
We solve the tensionless string in a constant plane wave background and
obtain a hugely degenerate spectrum. This is the case for a large class of
plane wave backgrounds. We show that the solution can also be derived as a
consistent limit of the quantized tensile theory of IIB strings in a pp-wave.
This is in contrast to the situation for several other backgrounds.Comment: 1+17 pages, LaTeX, minor corrections, added new reference
Toroidal p-branes, anharmonic oscillators and (hyper)elliptic solutions
Exact solvability of brane equations is studied, and a new invariant anzats for the solution of -brane
equations in -dimensional Minkowski space is proposed. The reduction
of the -brane Hamiltonian to the Hamiltonian of -dimensional relativistic
anharmonic oscillator with the monomial potential of the degree equal to
is revealed. For the case of degenerate p-torus with equal radii it is shown
that the -brane equations are integrable and their solutions are expressed
in terms of elliptic () or hyperelliptic () functions. The solution
describes contracting -brane with the contraction time depending on and
the brane energy density. The toroidal brane elasticity is found to break down
linear Hooke law as it takes place for the anharmonic elasticity of smectic
liquid crystals.Comment: 18 pages, extended version accepted in Nucl. Phys. B; discussions on
integrability and geometric approach added; correspondence between anharmonic
elasticity in toroidal branes and smectic liquid crystals revealed;
references and acknowledgements updated; typos correcte
Extra Gauge Symmetry for Extra Supersymmetry
It is shown that the extra supersymmetry of tensionless superstring and super
-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 -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 -brane Lagrangian. A connection of
the presented gauge symmetries with massless higher spin gauge theories and a
symmetric phase of /string-theory is discussed.Comment: Latex, 10 pages; references and few comments added for section 1. To
appear in Phys. Lett.
Generalized hooke law for relativistic membranes and p-branes
The character of elastic forces of relativistic membranes and p-branes encoded in their nonlinear equations is studied.
The toroidal brane equations are reduced to the classical equations of anharmonic elastic media described by monomial
potentials. Integrability of the equations is discussed and some of their exact solutions are constructed.Исследуется характер сил упругости, задаваемых нелинейными уравнениями релятивистских мембран и р-бран. Уравнения тороидальных бран преобразуются к классическим уравнениям ангармонических упругих сред, описываемых мономиальными потенциалами. Обсуждается интегрируемость полученных уравнений и находятся некоторые их частные решения.Досліджується характер сил пружності, які задані нелінійними рівняннями релятивістських мембран та р-бран. Рівняння тороідальних бран перетворюються у класичні рівняння ангармонічних пружних середовищ, що описуються мономіальними потенціалами. Обговорюється інтегрування отриманих рівнянь. Знайдені їх деякі часткові рішення
Constrained generalized supersymmetries and superparticles with tensorial central charges. A classification
We classify the admissible types of constraint (hermitian, holomorphic, with
reality conditions on the bosonic sectors, etc.) for generalized
supersymmetries in the presence of complex spinors. We further point out which
constrained generalized supersymmetries admit a dual formulation. For both real
and complex spinors generalized supersymmetries are constructed and classified
as dimensional reductions of supersymmetries from {\em oxidized} space-times
(i.e. the maximal space-times associated to -component Clifford irreps). We
apply these results to sistematically construct a class of models describing
superparticles in presence of bosonic tensorial central charges, deriving the
consistency conditions for the existence of the action, as well as the
constrained equations of motion. Examples of these models (which, in their
twistorial formulation, describe towers of higher-spin particles) were first
introduced by Rudychev and Sezgin (for real spinors) and later by Bandos and
Lukierski (for complex spinors).Comment: 32 pages, LaTe
Hamiltonian structure and noncommutativity in -brane models with exotic supersymmetry
The Hamiltonian of the simplest super -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
-brane coordinates and find the D.B. realization of the
superalgebra. Established is the coincidence of the D.B. and Poisson bracket
realizations of the superalgebra on the constraint surface and the
absence there of anomaly terms in the commutation relations for the quantized
generators of the superalgebra.Comment: Latex, 27 pages, no figures. Latex packages amsfonts and euscript are
use
Strings in a Space with Tensor Central Charge Coordinates
New string models in D=4 space-time extended by tensor central charge
coordinates are constructed. We use the coordinates to
generate string tension using a minimally extended string action linear in
. It is shown that the presence of 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 with describing a spin wave process. A
supersymmetric version of the proposed model is formulated.Comment: 10 pages, Latex, style file espcrc2.sty. Talk given by AZ at the D.V.
Volkov Memorial Conference ``Supersymmetry and Quantum Field Theory'', July
25-30, 2000, Kharkov, to be published in the Nuclear Physics B Conference
Supplement