PHASE TRANSITION OF SPACETIME AND STRING THEORY
Project/Area Number  03640272 
Research Category 
GrantinAid for General Scientific Research (C)

Allocation Type  Singleyear Grants 
Research Field 
核・宇宙線・素粒子

Research Institution  Osaka University 
Principal Investigator 
KIKKAWA Kenji OSAKA UNIVERSITY, FACULITY OF SCIENCE,PROF., 理学部, 教授 (10011545)

Project Period (FY) 
1991 – 1993

Project Status 
Completed(Fiscal Year 1993)

Budget Amount *help 
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1993 : ¥200,000 (Direct Cost : ¥200,000)
Fiscal Year 1992 : ¥200,000 (Direct Cost : ¥200,000)
Fiscal Year 1991 : ¥1,600,000 (Direct Cost : ¥1,600,000)

Keywords  Generation of Gauge Symmetry / The Berry phase / Generation of Kinetic Energy Term / KaluzaKlein Mechanism / Two Dimensional Quantum Universe / Solenoid Field / String in Critical Dimensions / Target Space / 非臨界次元の弦 / ゲージ対称性の誘発 / 時空のコンパクト化 / 時空の位相構造 / GUTエネルギー / インスタントン / EguchiーHanson解 / Induced Gauge Theory / BornーOppenheimer法 / コンパクト化 
Research Abstract 
In the past three years, we have studied (1) a possibility of a dynamical generation of a local gauge symmetry in quantum field theory, and (2) some problems in the quantum cosmology. 1. Usually one belives that the gauge symmetry in our world is being imposed as a principle form the out set, and then it is destroyed in low energy region by the spontaneous symmetry breakdown. Hence the higher symmetry is observed as the energy increased. In our research, however, we found an opposite case, i. e., the symmetry in low energy is higher than the one originally imposed. This phenomenon occurs when a part of the spacetime is compactified by the KakuzaKlein mechanism(KKM). Although KKM reduces the original symmetry, a new mechanism generates a new dynamical gauge symmetry. This is able to be identified with a berry phase effect. The model demonstrated here is a U(1) gauge theory in the 6d Minkowski space M_4. If M_6 is compacitified into M_4 times a 2d compact Riemann surface with genus g, T_8, the gouge symmetry in the space M_4 becames [U(1)]^g. The kinetic ebergy terms for the gauge fields are proven to ve generated. The fields can be associated terms for the gauge fields are proven to be generated. The fields can be associated with the solenoid fields of T_g. The mechanism can be extended for the generation of nonabelian theory. 2. In quantum cosmology we studied the dual string theories in critical dimensions as a model of two dimennsional quantum cosmology. We identified all observables that intelligent creatures who live in the 2d universe could observe. They can recognize the target space structure. The study suggests us a many of new interpretations of physical concepts. The spin and the isospin, for instance, are able to ve interpreted on the asme footing.

Report
(4results)
Research Output
(11results)