4,385 research outputs found
Non-Critical Covariant Superstrings
We construct a covariant description of non-critical superstrings in even
dimensions. We construct explicitly supersymmetric hybrid type variables in a
linear dilaton background, and study an underlying N=2 twisted superconformal
algebra structure. We find similarities between non-critical superstrings in
2n+2 dimensions and critical superstrings compactified on CY_(4-n) manifolds.
We study the spectrum of the non-critical strings, and in particular the
Ramond-Ramond massless fields. We use the supersymmetric variables to construct
the non-critical superstrings sigma-model action in curved target space
backgrounds with coupling to the Ramond-Ramond fields. We consider as an
example non-critical type IIA strings on AdS_2 background with Ramond-Ramond
2-form flux.Comment: harvmac, amssym, 46 p
Lower-dimensional pure-spinor superstrings
We study to what extent it is possible to generalise Berkovits' pure-spinor
construction in d=10 to lower dimensions. Using a suitable definition of a
``pure'' spinor in d=4,6, we propose models analogous to the d=10 pure-spinor
superstring in these dimensions. Similar models in d=2,3 are also briefly
discussed.Comment: 17 page
NeXSPheRIO results on elliptic flow at RHIC and connection with thermalization
Elliptic flow at RHIC is computed event-by-event with NeXSPheRIO. Reasonable
agreement with experimental results on is obtained. Various effects
are studied as well: reconstruction of impact parameter direction, freeze out
temperature, equation of state (with or without crossover), emission mecanism.Comment: Contribution to the Proceedings of the Quark-Gluon Plasma
Thermalization workshop. Content slightly increase
Simple solutions of relativistic hydrodynamics for longitudinally expanding systems
Simple, self-similar, analytic solutions of 1+1 dimensional relativistic
hydrodynamics are presented, generalizing Bjorken's solution to inhomogeneous
rapidity distribution.Comment: 12 pages, elsart.cls, 2 eps figure
Towards Pure Spinor Type Covariant Description of Supermembrane -- An Approach from the Double Spinor Formalism --
In a previous work, we have constructed a reparametrization invariant
worldsheet action from which one can derive the super-Poincare covariant pure
spinor formalism for the superstring at the fully quantum level. The main idea
was the doubling of the spinor degrees of freedom in the Green-Schwarz
formulation together with the introduction of a new compensating local
fermionic symmetry. In this paper, we extend this "double spinor" formalism to
the case of the supermembrane in 11 dimensions at the classical level. The
basic scheme works in parallel with the string case and we are able to
construct the closed algebra of first class constraints which governs the
entire dynamics of the system. A notable difference from the string case is
that this algebra is first order reducible and the associated BRST operator
must be constructed accordingly. The remaining problems which need to be solved
for the quantization will also be discussed.Comment: 40 pages, no figure, uses wick.sty; v2: a reference added, published
versio
BFT embedding of the Green-Schwarz superstring and the pure spinor formalism
We worked out the Batalin-Fradkin-Tyutin (BFT) conversion program of second
class constraints to first class constraints in the GS superstring using light
cone coordinates. By applying this systematic procedure we were able to obtain
a gauge system that is equivalent to the recent model proposed by Berkovits and
Marchioro to relate the GS superstring to the pure spinor formalism.Comment: 12 pages latex2e, v2 typos fixed, v3 published in JHE
Pure-spinor superstrings in d=2,4,6
We continue the study of the d=2,4,6 pure-spinor superstring models
introduced in [1]. By explicitly solving the pure-spinor constraint we show
that these theories have vanishing central charge and work out the (covariant)
current algebra for the Lorentz currents. We argue that these super-Poincare
covariant models may be thought of as compactifications of the superstring on
CY_{4,3,2}, and take some steps toward making this precise by constructing a
map to the RNS superstring variables. We also discuss the relation to the so
called hybrid superstrings, which describe the same type of compactifications.Comment: 27 page
Relating the Green-Schwarz and Pure Spinor Formalisms for the Superstring
Although it is not known how to covariantly quantize the Green-Schwarz (GS)
superstring, there exists a semi-light-cone gauge choice in which the GS
superstring can be quantized in a conformally invariant manner. In this paper,
we prove that BRST quantization of the GS superstring in semi-light-cone gauge
is equivalent to BRST quantization using the pure spinor formalism for the
superstring.Comment: 16 pages, JHEP format, fixed typos and added 2 footnote
- …