scholarly journals A CONTINUUM STRING MODEL FOR D>1

1992 ◽  
Vol 07 (18) ◽  
pp. 1667-1677 ◽  
Author(s):  
M. MARTELLINI ◽  
M. SPREAFICO ◽  
K. YOSHIDA
Keyword(s):  
Classical Result ◽  
2D Gravity ◽  
Central Charge ◽  
String Model ◽  
String Tension ◽  
The Real ◽  
Gauge Fixing ◽  
Weyl Symmetry ◽  
Taking Care

The non-critical string (2D gravity coupled to the matter with central charge D) is quantized by taking care of both diffeomorphism and Weyl symmetries. In incorporating the gauge fixing with respect to the Weyl symmetry, through the condition Rg=const., one modifies the classical result of Distler and Kawai. In particular one obtains the real string tension for an arbitrary value of central charge D.

A Continuum Approach to 2D-Quantum Gravity for c>1

1997 ◽  
Vol 11 (26n27) ◽  
pp. 3247-3279
Author(s):  
M. Martellini ◽  
M. Spreafico ◽  
K. Yoshida
Keyword(s):  
Quantum Gravity ◽  
Scalar Curvature ◽  
Free Parameter ◽  
Central Charge ◽  
Flat Space ◽  
String Tension ◽  
Physical Significance ◽  
Two Dimensional ◽  
Continuum Approach ◽  
Gauge Fixing

Two dimensional induced quantum gravity with matter central charge c>1 is studied by carefully treating both diffeomorphism and Weyl symmetries. It is shown that, for the gauge fixing condition R(g) (scalar curvature) = const, one obtains a modification of the David–Distler–Kawai version of KPZ scaling. We obtain a class of models with real string tension for all values c>1. They contain a free parameter which is, however, strongly constrained by the requirement of the non triviality of the model. The possible physical significance of the new model is discussed. In particular we note that it describes smooth surfaces imbedded in d-dimensional flat space time for arbitrary d, which is consistent with recent numerical results for d=3.

scholarly journals THE EFFECTIVE STRING OF 3D Z2 GAUGE THEORY AS A c = 1 COMPACTIFIED CFT

1993 ◽  
Vol 08 (16) ◽  
pp. 2839-2858 ◽  
Author(s):  
M. CASELLE ◽  
F. GLIOZZI ◽  
S. VINTI ◽  
R. FIORE
Keyword(s):  
Field Theory ◽  
Monte Carlo ◽  
Conformal Field Theory ◽  
Central Charge ◽  
Three Dimensional ◽  
String Tension ◽  
Gauge Model ◽  
Expectation Values ◽  
Monte Carlo Test ◽  
Conformal Field

We report on a high precision Monte Carlo test of the three-dimensional Ising gauge model at finite temperature. The string tension σ is extracted from the expectation values of correlations of Polyakov lines. Agreement with the string tension extracted from Wilson loops is found only if the quantum fluctuations of the flux tube are properly taken into account. The central charge of the underlying conformal field theory is c = 1.

THE APPEARANCE OF MATTER FIELDS FROM QUANTUM FLUCTUATIONS OF 2D-GRAVITY

1989 ◽  
Vol 04 (22) ◽  
pp. 2125-2139 ◽  
Author(s):  
V.A. KAZAKOV
Keyword(s):  
Quantum Gravity ◽  
Cosmological Constant ◽  
Critical Exponent ◽  
2D Gravity ◽  
Central Charge ◽  
Quantum Fluctuations ◽  
Two Dimensional ◽  
Conformal Fields ◽  
Exactly Solvable ◽  
Matter Fields

It is established that various critical regimes may occur for a model of two-dimensional pure quantum gravity. These regimes correspond to the presence of effective fields with scaling dimensions Δk=−γ str ·k/2, k=1, 2, 3 ..., where γ str =−1/m, m=2, 3, 4 ... is the critical exponent of “string susceptibility” (with respect to the cosmological constant). This behaviour is typical for unitary conformal fields with the central charge c=1−6/m(m+1) in the presence of 2D-quantum gravity. We use the framework of loop equations for the invariant boundary functional, which are exactly solvable in this case.

scholarly journals Hamiltonian Approach to QCD in Coulomb Gauge: A Survey of Recent Results

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
H. Reinhardt ◽  
G. Burgio ◽  
D. Campagnari ◽  
E. Ebadati ◽  
J. Heffner ◽  
...  
Keyword(s):  
Spatial Dimension ◽  
String Tension ◽  
Quark Condensate ◽  
Coulomb Gauge ◽  
Hamiltonian Approach ◽  
Critical Temperatures ◽  
Yang Mills ◽  
Center Vortex ◽  
Gauge Fixing ◽  
Deconfinement Phase Transition

We report on recent results obtained within the Hamiltonian approach to QCD in Coulomb gauge. Furthermore this approach is compared to recent lattice data, which were obtained by an alternative gauge-fixing method and which show an improved agreement with the continuum results. By relating the Gribov confinement scenario to the center vortex picture of confinement, it is shown that the Coulomb string tension is tied to the spatial string tension. For the quark sector, a vacuum wave functional is used which explicitly contains the coupling of the quarks to the transverse gluons and which results in variational equations which are free of ultraviolet divergences. The variational approach is extended to finite temperatures by compactifying a spatial dimension. The effective potential of the Polyakov loop is evaluated from the zero-temperature variational solution. For pure Yang–Mills theory, the deconfinement phase transition is found to be second order for SU(2) and first order for SU(3), in agreement with the lattice results. The corresponding critical temperatures are found to be 275 MeV and 280 MeV, respectively. When quarks are included, the deconfinement transition turns into a crossover. From the dual and chiral quark condensate, one finds pseudocritical temperatures of 198 MeV and 170 MeV, respectively, for the deconfinement and chiral transition.

scholarly journals Covariant perturbations in the gonihedric string model

2017 ◽  
Vol 32 (32) ◽  
pp. 1750192 ◽  
Author(s):  
Efraín Rojas
Keyword(s):  
Extrinsic Curvature ◽  
String Model ◽  
Scalar Fields ◽  
Small Perturbations ◽  
Single Wave ◽  
Quadratic Mean ◽  
Gauge Fixing ◽  
Special Limit ◽  
The Stability ◽  
Jacobi Equations

We provide a covariant framework to study classically the stability of small perturbations on the so-called gonihedric string model by making precise use of variational techniques. The local action depends on the square root of the quadratic mean extrinsic curvature of the worldsheet swept out by the string, and is reparametrization invariant. A general expression for the worldsheet perturbations, guided by Jacobi equations without any early gauge fixing, is obtained. This is manifested through a set of highly coupled nonlinear differential partial equations where the perturbations are described by scalar fields, [Formula: see text], living in the worldsheet. This model contains, as a special limit, to the linear model in the mean extrinsic curvature. In such a case the Jacobi equations specialize to a single wave-like equation for [Formula: see text].

Soundproofing Scandal

2020 ◽  
pp. 68-99
Author(s):  
Justin Gautreau
Keyword(s):  
Detective Fiction ◽  
The Political ◽  
Dirty Work ◽  
The Real ◽  
Taking Care

This chapter argues that hard-boiled detective fiction provided disillusioned screenwriters with a platform to project a fantasy version of themselves and preserve what was left of their ego under studio employment. Where the screenwriter felt emasculated, creatively stunted, and expendable, the hard-boiled detective was characteristically tough, autonomous, and invaluable in taking care of the studio’s dirty work. Meanwhile, in their aim to disrupt the promotional façade of Hollywood, these writers found inspiration not only in the political limits of the screen but also in the industry’s ongoing efforts to regulate Hollywood as a place. A.C. and Carmen Edington’s novel The Studio Murder Mystery and Raoul Whitfield’s Death in a Bowl therefore created a critical lens through which to view the “real” Hollywood in the era of the talkies. These novels treat Hollywood Boulevard and the Hollywood Bowl as extensions of soundstages where stars perform their studio-mandated morals clause for an unsuspecting public. It is only by realizing that movie “magic” is no longer exclusive to studio lots that the detective can solve the mystery.

Densities of the extreme eigenvalues of Beta–MANOVA matrices

2018 ◽  
Vol 08 (01) ◽  
pp. 1950002 ◽  
Author(s):  
Raymond Kan ◽  
Plamen Koev
Keyword(s):  
Classical Result ◽  
Real Case ◽  
The Real ◽  
Extreme Eigenvalues

We derive new expressions for the densities of extreme eigenvalues of a Beta–MANOVA matrix, which generalize the classical result of Khatri for the real case. We also present new expressions for the distributions of those eigenvalues which are valid for any values of the parameters.

VIRASORO ALGEBRA IN THE KN ALGEBRA: BOSONIC STRING WITH FERMIONIC GHOSTS ON RIEMANN SURFACES

1991 ◽  
Vol 06 (31) ◽  
pp. 2861-2870
Author(s):  
HIROSHI KOIBUCHI
Keyword(s):  
Clifford Algebra ◽  
Riemann Surfaces ◽  
Central Charge ◽  
Virasoro Algebra ◽  
String Model ◽  
Bosonic String ◽  
Combined System

The bosonic string model with fermionic ghosts is considered in the framework of the KN algebra. Our attentions are paid to representations of KN algebra and a Clifford algebra of the ghosts. We show that a Virasoro-like algebra is obtained from KN algebra when KN algebra has certain antilinear anti-involution, and that it is isomorphic to the usual Virasoro algebra. We show that there is an expected relation between a central charge of this Virasoro-like algebra and an anomaly of the combined system.

scholarly journals LIOUVILLE COSMOLOGY AT ZERO AND FINITE TEMPERATURES

2006 ◽  
Vol 21 (07) ◽  
pp. 1379-1444 ◽  
Author(s):  
JOHN ELLIS ◽  
NIKOLAOS E. MAVROMATOS ◽  
MICHAEL WESTMUCKETT ◽  
DIMITRI V. NANOPOULOS
Keyword(s):  
Zero Mode ◽  
Central Charge ◽  
Metastable Phase ◽  
String Model ◽  
Closed String ◽  
Target Space ◽  
Late Time ◽  
Time Behavior ◽  
Target Time ◽  
Inflationary Phase

We discuss cosmology in the context of Liouville strings, characterized by a central-charge deficit Q2, in which target time is identified with (the worldsheet zero mode of the) Liouville field: Q-Cosmology. We use a specific example of colliding braneworlds to illustrate the phase diagram of this cosmological framework. The collision provides the necessary initial cosmological instability, expressed as a departure from conformal invariance in the underlying string model. The brane motion provides a way of breaking target-space supersymmetry, and leads to various phases of the brane and bulk Universes. Specifically, we find a hot metastable phase for the bulk string Universe soon after the brane collision in which supersymmetry is broken, which we describe by means of a subcritical worldsheet σ-model dressed by a spacelike Liouville field, representing finite temperature (Euclidean time). This phase is followed by an inflationary phase for the brane Universe, in which the bulk string excitations are cold. This is described by a super-critical Liouville string with a timelike Liouville mode, whose zero mode is identified with the Minkowski target time. Finally, we speculate on possible ways of exiting the inflationary phase, either by means of subsequent collisions or by deceleration of the brane Universe due to closed-string radiation from the brane to the bulk. While phase transitions from hot to cold configurations occur in the bulk string universe, stringy excitations attached to the braneworld remain thermalized throughout, at a temperature which can be relatively high. The late-time behavior of the model results in dilaton-dominated dark energy and present-day acceleration of the expansion of the Universe, asymptoting eventually to zero.

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