arXiv subjects

Kazuo Ghoroku

Publications and source records attributed to Kazuo Ghoroku.

66 records · Page 4Linked to original sources

arXiv1999

Yang-Mills theory from non-critical string

The correspondence of the non-critical string theory and the Yang-Mills theory is examined according to the recent Polyakov's proposal, and two possible solutions of the bulk equations are addressed near the fixed points of the pure Yang-Mills theory: (i) One solution asymptotically approaches to the AdS space at the ultraviolet limit where the conformally invariant field theory is realized. (ii) The second one approaches to the flat space in both the infrared and the ultraviolet limits. The area law of the Wilson-loop and the asymptotic freedom with logarithmic behaviour are seen in the respective limit.

hep-th↗

arXiv1997

Solitonic d-5 brane and Vortex on the World-Sheet

We examine the behavior of the vortex defects, which are represented by the sine-Gordon potential, on the world-sheet when a solitonic d-5 brane is existing in the d-dimensional target space. The d-5 brane solution is obtained as an extension of 5-brane in 10d supergravity. It is shown that the vortices of any charge should be dissociated to the free gas when they approach to the brane. The meanings of this fact are addressed through the analysis of the renormalization group equations on the world sheet.

hep-th↗

arXiv1996

Field condensations and Noncritical String for c>1

Quantum theory of 2d gravity for $c>1$ is examined as a non-critical string theory by taking account of the loop-correction of open strings whose end points are on the 2d world surface of the closed string. This loop-correction leads to a conformal anomaly, and we obtain a modified target-space action which implies a new phase of the non-critical closed-string. In this phase, the dual field of the gauge field, which lives on the boundary, condenses and the theory can be extended to $c>1$ without any instability.

hep-th↗

arXiv1996

Effective Potential in String Induced Action

The dynamical properties of the gauge theory of Born-Infeld type action, which is expected as the high-energy effective theory, are investigated by adding a complex scalar field to this gauge system. Especially the Coleman-Weinberg mechanism is addressed in this theory.

hep-th↗

arXiv1996

String loop correction and the condensation of tachyon in 2d gravity

Quantum theory of 2d gravity is examined by including a special quantum correction, which corresponds to the open string loop corrections and provides a new conformal anomaly for the corresponding $σ$ model. This anomaly leads to the condensation of the tachyon, and the resultant effective theory implies a possibility of extending the 2d gravity to the case of $c>1$.

hep-th↗

arXiv1996

CP^{N-1} models and the Quantized 2D Black Holes

We have examined the coupled system of the dilaton gravity and the $CP^{N-1}$ theory known as a model of the confinement of massive scalar quarks. After the quantization of the system, we could see the quantum effect of the gravitation on the coupling constant of $CP^{N-1}$ model and how the coupling constant of dynamically induced gauge field changes near the black hole configuration.

hep-th↗

arXiv1995

On the validity of ADM formulation in 2D quantum gravity

We investigate 2d gravity quantized in the ADM formulation, where only the loop length $l(z)$ is retained as a dynamical variable of the gravitation, in order to get an intuitive physical insight of the theory. The effective action of $l(z)$ is calculated by adding scalar fields of conformal coupling, and the problems of the critical dimension and the time development of $l$ are addressed.

hep-th↗

arXiv1995

Quantized 2d Dilaton Gravity and Black Holes

We have examined a modified dilaton gravity whose action is separable into the kinetic and the cosmological terms for the sake of the quantization. The black hole solutions survive even in the quantized theory, but the ADM mass of the static solution is unbounded from below. Quantum gravitational effect on the interacting matter field and the string susceptibility of the dilaton gravity are also examined.

hep-th↗

arXiv1994

Conformally Exact Black Hole Perturbed by a Marginal Operator

We have examined effective theory induced by gauged WZW models, in which the tachyon field is added as a marginal operator. Due to this operator added, we must further add the higher order corrections, which modifies the original configuration, to make the theory full-conformally invariant. It has been found that 2d is a critical dimension in the sense that the metric obtained from gauged WZW is modified by the tachyon condensation for $d>2$, but not for $d\le 2$.

hep-th↗

arXiv1994

Hawking Temperature and String Scattering off the 2+1 Black Hole

The 2+1 black hole anti de Sitter solution, obtained as a special limit of the conformally exact $SL(2,R)\otimes SO(1,1)/SO(1,1)$ coset WZW model to all orders in 1/k, is investigated with respect to tachyon scattering. We calculate the off-shell reflection and transmission coefficients and we find an expression for the Hawking temperature, which in a certain limit reduces to the statistical result.

hep-th↗

arXiv1993

2D Quantum Gravity Coupled to Renormalizable Matter Fields

We consider two-dimensional quantum gravity coupled to matter fields which are renormalizable, but not conformal invariant. Questions concerning the $\b$ function and the effective action are addressed, and the effective action and the dressed renormalization group equations are determined for various matter potentials.

hep-th↗

arXiv1993

An approach to quantum gravity from 4-$ε$ dimension

A calculational scheme of quantum-gravitational effects on the physical quantities is proposed. The calculations are performed in 4-$ε$ dimension with $1/N$-expansion scheme, where the Einstein gravity is renormalizable and it has an ultraviolet fixed-point within the 1/N-expansion. In order to perform a consistent perturbation in $4-ε$ dimension, spin-3/2 fields should be adopted as the N matter-fields whose loop-corrections are included in the effective action. After calculating the physical quantities at $4-ε$ dimension, the four-dimensional aspects of them can be seen by taking the limit of $ε=0$. In taking this limit, any higher derivative terms are not introduced as the counter terms since no divergence appears at $ε=0$ in our scheme. According to this approach, we have examined the effective potential of a scalar field to see the possibility of the spontaneous symmetry breaking due to the gravitational loop corrections.

hep-th↗