Renormalization of Long-wavelength Solution of Einstein Equation

Using the renormalization group method, we improved the first order solution of the long-wavelength expansion of the Einstein equation. By assuming that the renormalization group transformation has the property of Lie group, we can regularize the secular divergence caused by the spatial gradient terms and absorb it to the background seed metric. The solution of the renormalization group equation shows that the renormalized metric describes the behavior of gravitational collapse in the expanding universe qualitatively well.Comment: 12 pages, 1 figure, typeset by REVTe

Renormalization group equations and integrability in Hamiltonian systems

We investigate Hamiltonian systems with two degrees of freedom by using renormalization group method. We show that the original Hamiltonian systems and the renormalization group equations are integrable if the renormalization group equations are Hamiltonian systems up to the second leading order of a small parameter.Comment: 7 pages, No figures, LaTeX (19 kb

Black Objects in the Gauge Theory of P-Branes

Within the context of the recently formulated classical gauge theory of relativistic p-branes minimally coupled to general relativity in D-dimensional spacetimes, we obtain solutions of the field equations which describe black objects. Explicit solutions are found for two cases: D > p+1 (true p-branes) and D = p+1 (p-bags).Comment: 9 pages, REVTEX 3.

Postmodern String Theory: Stochastic Formulation

In this paper we study the dynamics of a statistical ensemble of strings, building on a recently proposed gauge theory of the string geodesic field. We show that this stochastic approach is equivalent to the Carath\'eodory formulation of the Nambu-Goto action, supplemented by an averaging procedure over the family of classical string world-sheets which are solutions of the equation of motion. In this new framework, the string geodesic field is reinterpreted as the Gibbs current density associated with the string statistical ensemble. Next, we show that the classical field equations derived from the string gauge action, can be obtained as the semi-classical limit of the string functional wave equation. For closed strings, the wave equation itself is completely analogous to the Wheeler-DeWitt equation used in quantum cosmology. Thus, in the string case, the wave function has support on the space of all possible spatial loop configurations. Finally, we show that the string distribution induces a multi-phase, or {\it cellular} structure on the spacetime manifold characterized by domains with a purely Riemannian geometry separated by domain walls over which there exists a predominantly Weyl geometry.Comment: 24pages, ReVTe

The back reaction and the effective Einstein's equation for the Universe with ideal fluid cosmological perturbations

We investigate the back reaction of cosmological perturbations on the evolution of the Universe using the renormalization group method. Starting from the second order perturbed Einstein's equation, we renormalize a scale factor of the Universe and derive the evolution equation for the effective scale factor which includes back reaction due to inhomogeneities of the Universe. The resulting equation has the same form as the standard Friedman-Robertson-Walker equation with the effective energy density and pressure which represent the back reaction effect.Comment: 16 pages, to appear in Phys. Rev.

Stability of color-flavor locked strangelets

The stability of color-flavor locked (CFL) strangelets is studied in the three-flavor Nambu--Jona-Lasinio model. We consider all quark flavors to be massless, for simplicity. By making use of the multiple reflection expansion, we explicitly take into account finite size effects and formulate the thermodynamic potential for CFL strangelets. We find that the CFL gap could be large enough so that the energy per baryon number of CFL strangelets is greatly affected. In addition, if the quark-quark coupling constant is larger than a certain critical value, there is a possibility of finding absolutely stable CFL strangelets.Comment: 7 pages, 3 figures, to appear in Int. J. Mod. Phys.

Spontaneous CP Symmetry Breaking at the Electroweak Scale

We present a top-condensation model in which the CP symmetry is spontaneously broken at the electroweak scale due to the condensation of two composite Higgs doublets. In particular the CP-violating phase of the CKM matrix is generated. A simpler model where only one quark family is included is also discussed. In this case, for a general four-fermion interaction ($G_{tb}\neq 0$), the particle spectrum is the one of the one Higgs doublet model.Comment: 25 pages, LaTeX. References and comment adde