Tachyon condensation and Boundary States in Bosonic String

We discuss tachyon configuration for the unoriented bosonic string theory which produces a bosonic string theory with SO(32) gauge symmetry in ten dimensions. It is closely related to the tachyon condensation scenario proposed by A. Sen. We also give the boundary state description of the tachyon condensation process, with some emphasis on the r\^ole of orbifold conformal field theory.Comment: Proceeding of the talk given at YITP workshop ``Tachyon condensation and boundary state''(October 27-29, 1999), latex fil

Some Additional Solutions of Conformal Turbulence

We made a careful study of Polyakov's Diofantian equations for 2D turbulence and found several additional CFTs which meet his criterion. This fact implies that we need further conditions for CFT in order to determine the exponent of the energy spectrum function.Comment: 7 pages, UT-62

Asymptotics of neutron Cooper pair in weakly bound nuclei

Asymptotic form of neutron Cooper pair penetrating to the exterior of nuclear surface is investigated with the Bogoliubov theory for the superfluid Fermions. Based on a two-particle Schr\"{o}dinger equation governing the Cooper pair wave function and systematic studies for both weakly bound and stable nuclei, the Cooper pair is shown to be spatially correlated even in the asymptotic large distance limit, and the penetration length of the pair condensate is revealed to be universally governed by the two-neutron separation energy $S_{2n}$ and the di-neutron mass $2m$

Improved Taylor Expansion method in the Ising model

We apply an improved Taylor expansion method, which is a variational scheme to the Ising model in two dimensions. This method enables us to evaluate the free energy and magnetization in strong coupling regions from the weak coupling expansion, even in the case of a phase transition. We determine the approximate value of the transition point using this scheme. In the presence of an external magnetic field, we find both stable and metastable physical states.Comment: 13 pages, 9 figure