Analysis of the dynamics in gauge and quantum gravity theories using the puregauge model
Project/Area Number  07640394 
Research Category 
GrantinAid for Scientific Research (C)

Allocation Type  Singleyear Grants 
Section  一般 
Research Field 
素粒子・核・宇宙線

Research Institution  KYOTO UNIVERSITY 
Principal Investigator 
HATA Hiroyuki Kyoto University, Groduate School of Science, Associate Professor, 大学院・理学研究科, 助教授 (70164837)

Project Period (FY) 
1995 – 1996

Project Status 
Completed(Fiscal Year 1996)

Budget Amount *help 
¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 1996 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1995 : ¥700,000 (Direct Cost : ¥700,000)

Keywords  gauge theory / quantum gravity / color confinement / BRST / monperturbative effect / topological field theory / string field theory 
Research Abstract 
The present research project aims at analyzing, on the basis of "puregauge model", nonperturbative dynamics expected to be working in YangMills theory and quantum gravity theory. The "puregauge model" is a kind of topological field theory obtained by restricting the gauge field A_<mu> (x) to the puregauge configurations A_<mu>=g^+E_<mu>g in YangMills theory, and by restricting the metric field to the configuration g_<munu> (x)=E_<mu>xi^<alpha> (x) E_<nu>xi^<beta> (x) h_<alphabeta> (xi (x)) in gravity theory. In the last academic year, we succeeded in developing a perturbation expansion method which, starting from the puregauge model, incorporates successively the fluctuations of the gauge field A_<mu> orthogonal to the gauge transformation. We also tried to apply the puregauge model to quantum gravity to solve the problem "Is the phase with unbroke general coordinate transformation invariance possible in four dimensional quantum gravity? ". In this academic year, we continued the research of applying the puregauge model to quantum gravity. However, due mainly to the following two problems, we have not yet obtained a definite answer and are still continuing the research : (1) Though we obtain the same kind of puregauge model as in YangMills theory if the background spacetime is a four sphere, the puregauge model corresponding to flat background is a free theory without nontrivial dynamics. (2) we do not know what are physically meaningful observables in quantum gravity theory. As other researches not directly related to the present project, we have carried out the followings and published the papers. (1) Construction of string field theory on Rindler spacetime and analysis of string thermalization. (2) Analysis of causality in covariant string field theory.

Report
(3results)
Research Output
(8results)