scholarly journals QUANTIZING HIGHER-SPIN STRING THEORIES

1995 ◽  
Vol 10 (14) ◽  
pp. 2123-2142 ◽  
Author(s):  
H. LU ◽  
X.J. WANG ◽  
K.-W. XU ◽  
C.N. POPE ◽  
K. THIELEMANS
Keyword(s):  
String Theory ◽  
Classical Theory ◽  
Energy Momentum Tensor ◽  
Standard Form ◽  
Momentum Tensor ◽  
Minimal Models ◽  
Classical Level ◽  
Higher Spin ◽  
String Theories ◽  
The Way

In this paper, we examine the conditions under which a higher-spin string theory can be quantized. The quantizability is crucially dependent on the way in which the matter currents are realized at the classical level. In particular, we construct classical realizations for the W2,s algebra, which is generated by a primary spin-s current in addition to the energy-momentum tensor, and discuss the quantization for s≤8. From these examples we see that quantum BRST operators can exist even when there is no quantum generalization of the classical W2,s algebra. Moreover, we find that there can be several inequivalent ways of quantizing a given classical theory, leading to different BRST operators with inequivalent cohomologies. We discuss their relation to certain minimal models. We also consider the hierarchical embeddings of string theories proposed recently by Berkovits and Vafa, and show how the already known W strings provide examples of this phenomenon. Attempts to find higher-spin fermionic generalizations lead us to examine whether classical BRST operators for [Formula: see text](n odd) algebras can exist. We find that even though such fermionic algebras close up to null fields, one cannot build nilpotent BRST operators, at least of the standard form.

scholarly journals ON HIGHER-SPIN GENERALIZATIONS OF STRING THEORY

1994 ◽  
Vol 09 (09) ◽  
pp. 1527-1543 ◽  
Author(s):  
H. LU ◽  
C. N. POPE ◽  
X. J. WANG
Keyword(s):  
String Theory ◽  
Gauge Field ◽  
Virasoro Algebra ◽  
Two Dimensional ◽  
Minimal Models ◽  
World Sheet ◽  
The World ◽  
Higher Spin ◽  
String Theories

We construct BRST operators for certain higher-spin extensions of the Virasoro algebra, in which there is a spin-s gauge field on the world sheet, as well as the spin-2 gauge field corrresponding to the two-dimensional metric. We use these BRST operators to study the physical states of the associated string theories, and show how they are related to certain minimal models.

scholarly journals ON LOOP EQUATIONS IN KdV EXACTLY SOLVABLE STRING THEORY

1992 ◽  
Vol 07 (14) ◽  
pp. 1263-1272 ◽  
Author(s):  
SIMON DALLEY
Keyword(s):  
String Theory ◽  
Cosmological Constant ◽  
The Other ◽  
Half Line ◽  
String Equation ◽  
Minimal Models ◽  
The Real ◽  
Exactly Solvable ◽  
Scale Transformations ◽  
String Theories

The non-perturbative behavior of macroscopic loop amplitudes in the exactly solvable string theories based on the KdV hierarchies is considered. Loop equations are presented for the real non-perturbative solutions living on the spectral half-line, allowed by the most general string equation [Formula: see text], where [Formula: see text] generates scale transformations. In general the end of the half-line (the 'wall') is a non-perturbative parameter whose role is that of boundary cosmological constant. The properties are compared with the perturbative behavior and solutions of [P, Q]=1. Detailed arguments are given for the (2,2m-1) models while generalization to the other (p,q) minimal models and c=1 is briefly addressed.

scholarly journals Implication of U-duality for black branes in string/M-theory

2016 ◽  
Vol 31 (01) ◽  
pp. 1650001
Author(s):  
Samrat Bhowmick
Keyword(s):  
String Theory ◽  
Explicit Form ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Time Dependent ◽  
Type Ii ◽  
Black Brane ◽  
Duality Symmetry ◽  
M Theory ◽  
Time Dependent System

U-duality symmetry of M-theory and S- and T-duality of string theory can be used to study various black brane solutions. We explore some aspect of this idea here. This symmetry can be used to get relations among various components of the metric of the black brane. These relations in turn give relations among various components of the energy–momentum tensor. We show that, using these relations, without knowing the explicit form of form fields, we can get the black brane solutions. These features were studied previously in the context of M-theory. Here, we extensively studied them in string theory (type II supergravity). We also show that this formulation works for exotic branes. We give an example of a time-dependent system where this method is essential.

STUDY OF THE BRS CHARGE IN THE POLYAKOV STRING BY THE KUGO-OJIMA METHOD

1988 ◽  
Vol 03 (04) ◽  
pp. 943-951
Author(s):  
J. ABAD ◽  
R. RODRIGUEZ-TRÍAS
Keyword(s):  
String Theory ◽  
Energy Momentum Tensor ◽  
Momentum Tensor

Using the method of Kugo and Ojima we obtain the Becchi-Rouet-Stora charge in the string theory proposed by Polyakov. When a conformal improved energy-momentum tensor is used, we obtain the same BRS charge that emerges from other methods.

scholarly journals NEW REALIZATIONS OF W ALGEBRAS AND W STRINGS

1992 ◽  
Vol 07 (20) ◽  
pp. 1835-1842 ◽  
Author(s):  
H. LU ◽  
C.N. POPE ◽  
S. SCHRANS ◽  
X.J. WANG
Keyword(s):  
Energy Momentum Tensor ◽  
Scalar Fields ◽  
Momentum Tensor ◽  
Intrinsic Interest ◽  
New Class ◽  
Free Scalar ◽  
To Come ◽  
String Theories

We discuss new realizations of W algebras in which the currents are expressed in terms of two arbitrary commuting energy-momentum tensors together with a set of free scalar fields. This contrasts with the previously-known realizations, which involve only one energy-momentum tensor. Since realizations of nonlinear algebras are not easy to come by, the fact that this new class exists is of intrinsic interest. We use these new realizations to build the corresponding W-string theories and show that they are effectively described by two independent ordinary Virasoro-like strings.

scholarly journals EFFECTS OF GAUGING ON SYMPLECTIC STRUCTURE, THE HOPF TERM COUPLED TO THE CP1 MODEL, AND FRACTIONAL SPIN

1999 ◽  
Vol 14 (10) ◽  
pp. 1561-1590 ◽  
Author(s):  
B. CHAKRABORTY ◽  
A. S. MAJUMDAR
Keyword(s):  
Symplectic Structure ◽  
Energy Momentum Tensor ◽  
Time Derivative ◽  
Momentum Tensor ◽  
Total Charge ◽  
Dynamical Structure ◽  
Independent Manner ◽  
Classical Level ◽  
Fractional Spin ◽  
Chern Simons

We couple the Hopf term to the relativistic CP 1 model and carry out the Hamiltonian analysis at the classical level in a gauge-independent manner. The symplectic structure of the model given by the set of Dirac brackets among the phase space variables is found to be the same as that of the pure CP 1 model. This symplectic structure is shown to be inherited from the global SU(2)-invariant S3 model, and undergoes no modification upon gauging the U(1) subgroup, except for the appearance of an additional first class constraint generating U(1) gauge transformation. We then address the question of fractional spin as imparted by the Hopf term at the classical level. For that we construct the expression of angular momentum through both the symmetric energy–momentum tensor and Noether's prescription. The two expressions agree for the model, indicating that no fractional spin is imparted by this term at the classical level in an approach which is different from the earlier analyses carried out in the literature. We next show that the model has to be altered à la Bowick et al., by using an identity (which is not a constraint as it involves a time derivative and thus changes the basic dynamical structure of the model) valid in the radiation gauge in order to yield the fractional spin given in terms of the soliton number. Finally, by making the gauge field of the CP 1 model dynamical by adding the Chern–Simons term, we find that the model ceases to be a CP 1 model, as is the case with its nonrelativistic counterpart. This model is also shown to reveal the existence of "anomalous" spin. This is, however, given in terms of the total charge of the system, rather than any soliton number.

CASIMIR EFFECT FOR THE ROBIN SURFACES IN STATIC ROBERTSON–WALKER SPACE–TIME

2011 ◽  
Vol 20 (02) ◽  
pp. 161-168 ◽  
Author(s):  
MOHAMMAD R. SETARE ◽  
M. DEHGHANI
Keyword(s):  
Scalar Field ◽  
Energy Momentum Tensor ◽  
Casimir Effect ◽  
Vacuum Expectation ◽  
Robin Boundary Condition ◽  
Momentum Tensor ◽  
Space Time ◽  
Conformally Invariant ◽  
Time Space ◽  
Robin Boundary

We investigate the energy–momentum tensor for a massless conformally coupled scalar field in the region between two curved surfaces in k = -1 static Robertson–Walker space–time. We assume that the scalar field satisfies the Robin boundary condition on the surfaces. Robertson–Walker space–time space is conformally related to Rindler space; as a result we can obtain vacuum expectation values of the energy–momentum tensor for a conformally invariant field in Robertson–Walker space–time space from the corresponding Rindler counterpart by the conformal transformation.

scholarly journals Cutoff AdS3 versus $$ T\overline{T} $$ CFT2 in the large central charge sector: correlators of energy-momentum tensor

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Yi Li ◽  
Yang Zhou
Keyword(s):  
Field Theory ◽  
Euclidean Plane ◽  
Energy Momentum Tensor ◽  
Central Charge ◽  
Momentum Tensor ◽  
Two Dimensional ◽  
Conformal Field ◽  
Operator Identity ◽  
Pure Gravity ◽  
Charge Sector

Abstract In this article we probe the proposed holographic duality between $$ T\overline{T} $$ T T ¯ deformed two dimensional conformal field theory and the gravity theory of AdS3 with a Dirichlet cutoff by computing correlators of energy-momentum tensor. We focus on the large central charge sector of the $$ T\overline{T} $$ T T ¯ CFT in a Euclidean plane and a sphere, and compute the correlators of energy-momentum tensor using an operator identity promoted from the classical trace relation. The result agrees with a computation of classical pure gravity in Euclidean AdS3 with the corresponding cutoff surface, given a holographic dictionary which identifies gravity parameters with $$ T\overline{T} $$ T T ¯ CFT parameters.

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