Gravitational string-membrane hedgehog and internal structure of black holes

We investigate charged Nambu-Goto strings/membrane systems in the Einstein-Maxwell theory in 3+1 dimensions. We first construct a charged string hedgehog solution that has a single horizon and conical singularity. Then we examine a charged membrane system, and give a simple derivation of its self energy. We find that the membrane may form an extremal Reissner-Nordstrom black hole, but its interior is a flat spacetime. Finally by combining the charged strings and the membrane we construct black hole solutions that have no singularities inside the horizons. We study them in detail by varying the magnitude of the two parameters, namely, the charge times the membrane tension and the string tension. We also argue that the strings have, due to the large redshift inside the system, a fair amount of degrees of freedom that may explain the entropy of the corresponding black holes.Comment: 22 pages, 13 figures, minor revisions, version published in PT

Size scaling of self gravitating polymers and strings

We study a statistical ensemble of a single polymer with self gravitational interaction. This is a model of a gravitating string --- the precursor of a black hole. We analyze averaged sizes by mean field approximations with an effective Hamiltonian a la Edwards with Newtonian potential as well as a contact repulsive interaction. We find that there exists a certain scaling region where the attractive and the repulsive forces balance out. The repulsive interaction pushes the critical gravitational coupling to a larger value, at which the size of a polymer becomes comparable to its Schwarzschild radius, and as a result the size of the corresponding black hole increases considerably. We show phase diagrams in various dimensions that clarify how the size changes as the strengths of repulsive and gravitational forces vary.Comment: 25 pages, 3 figures; ver 2, discussion in Sec 2 has been extended and reorganized. Figures are added to illustrate the size scalings with respect to the couplings. Ver 3. Typos corrected. Final version to appear in PTE

Quantization of fields based on Generalized Uncertainty Principle

We construct a quantum theory of free scalar field in 1+1 dimensions based on a `Generalized Uncertainty Principle'. Both canonical and path integral formalism are employed. Higher dimensional extension is easily performed in the path integral formalism.Comment: 17pages, 2figure

Improved Renormalization Group analysis for Yang-Mills theory

We apply an improved renormalization group analysis for pure Yang-Mills theory at one loop order and obtained the result that a non-perturbatively generated pole mass of gluon emerges as $M_P^2/\Lambda^2 \simeq 0.66$, where $\Lambda$ is the $MS$-bar scale.Comment: 1+16 pages, 3 figures; ver 2, typos corrected, and some comments and references added; ver 3, some sentences corrected, a figure replaced and a number corrected; ver 4, in sec 2, the derivation of the main formula is refined, final version to appear in Prog.Theor.Phy

String creation in D6-brane background

The production of string charge during a crossing of certain oriented D-branes is studied. We compute the string charge in the system of a probe D2-brane and a background D6-brane by use of the equations of motion in the ten-dimensions. We confirm the creation of string charge as inflow from the background D6-brane.Comment: 11 pages, 1 figure, typos correcte

Thermal Hadron Spectrum in e+e- Annihilation From Gauge-String Duality

We compute the inclusive spectrum of produced particles in e+e- annihilation in confining gauge theories that have a gravity dual and show that the momentum distribution exhibits thermal behavior