Nonperturbative formulation of string theory by fermions and the study of black holes
| Project/Area Number |
10640286
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | RIKKYO UNIVERSITY |
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Principal Investigator |
YAHIKOZAWA Shigeaki RIKKYO UNIV., COLLEGE OF SCIENCE, ASSIST.PROFESSOR, 理学部, 助教授 (00192790)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1998: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | string theory / black hole / D-brane / non-critical string / spacetime singularity / soliton / shock wave / Aichelburg-Sexl spacetime / ストリング理論 / ホライズン / Aichelburg-Sexl時空 / D6-D2 / enhancon / D-brane / string theory / noncritical string / D-instanton / nonperturbative effect / soliton / string field theory / 非摂動的定式化 / D-Instanton / 非臨界弦 / String field / 組み合わせ論 / string equation |
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| Research Abstract |
The purpose of this research is to construct a nonperturbative formulation of string theory by studying it from the viewpoints of solitons. D-branes. fermions. singularities of spacetime and black holes.
First, we suggest that the boundary cosmological constant ζ in c<1 unitary string theory be regarded as the one-dimensional complex coordinate of the target space on which the boundaries of world-sheets can live. From this viewpoint we explicitly construct analogues of D-instantons which satisfy Polchinsk's "combinatories of boundaries." We further show that our operator formalism developed in the preceding articles is powerful in evaluating D-instanton effects, and also demonstrate for simple cases that these effects exactly coincide with the stringy nonperturbative effects found in the exact solutions of string equations.
Next, we investigate how much a first-quantized charged bosonic test string gets excited after crossing a shock wave generated by a charged particle with mass M^^- and charge Q^^-. The shock wave is given by a charged Aichelburg-Sexl (CAS) spacetime where Q^^- = 0 corresponds to the ordinary Aichelburg-Sexl one. We compute the mass expectation value of the charged test string after passing through the shock wave in the CAS spacetime. In the case of small Q^^-, gravitational and Coulomb forces are canceled out each other and hence the excitation of the string remains very small. In the case of large Q^^-, however, every charged string gets highly excited by quantum fluctuation in the extra-dimension caused by both the gauge and the axion fields.
We have been also studying the enhancon mechanism for the D6-D2 system.
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Report
(4 results)
Research Products
(7 results)
