繰り込み可能かつユニタリーな重力理論の探求:理論的・現象論的観点より
Project/Area Number |
19F19324
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Research Category |
Grant-in-Aid for JSPS Fellows
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Allocation Type | Single-year Grants |
Section | 外国 |
Review Section |
Basic Section 15010:Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics
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Research Institution | Tokyo Institute of Technology |
Host Researcher |
山口 昌英 東京工業大学, 理学院, 教授 (80383511)
|
Foreign Research Fellow |
BUONINFANTE LUCA 東京工業大学, 理学院, 外国人特別研究員
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Project Period (FY) |
2019-11-08 – 2022-03-31
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Project Status |
Granted (Fiscal Year 2021)
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Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2021: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2020: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2019: ¥500,000 (Direct Cost: ¥500,000)
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Keywords | gravity |
Outline of Research at the Start |
本研究は、一般相対性理論を拡張し、くりこみ可能かつユニタリーである重力理論を構築しようというものです。一般に、2階以上の有階な高階微分を含む非特異な系ではゴースト不安定性が出ると考えられております。一方、Lee-Wick理論においては、運動方程式は6階微分方程式にも関わらず、量子論においてユニタリーであることが知られています。まずは、この系をハミルトン解析等により古典論も含めて徹底的に解析することが最初の目的です。また、つい最近、このLee-Wick理論の非局所版と言える理論が提唱されました。このような系が古典的・量子論的にくりこみ可能かつユニタリーであるかを調べることが第二の目的です。
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Outline of Annual Research Achievements |
During his first five months as a JSPS postdoctoral fellow he has started and completed five research projects. The achieved results are very interesting and are now part of five scientific publications/pre-prints. One project was based on quantum aspects of analytic nonlocal field theories. He found an iterative method to generate an infinite class of new nonlocal field theories whose propagators are ghost-free. He applied his results to several cases: spin-0, spin-1/2, and spin-2 fields; and discussed some physical implications like the regularization of curvature singularity. In another work, he analysed spacetime rotating metrics in quadratic theories of gravity and found the most general solution in the weak-field and slow rotation regime. As a physical application he investigated the light bending by a slowly rotating source in both cases of local and nonlocal theories. The other three projects are related to quantum aspects of black holes. One focused on the meaning and physical implications of the peculiar tendency of black holes to saturate several inequalities that need to hold true according to the laws of quantum mechanics. Whereas the other two were based on models of quantum black holes motivated by quantum corrections at the horizon scale. One dealt with corrections induced by the existence of a Generalized Uncertainty Principle, while the other on the assumption that black holes are corpuscular, i.e., made up of gravitons. In both cases relevant phenomenological implications were discussed.
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Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
He has already obtained new good results.
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Strategy for Future Research Activity |
He is currently working on three different projects which he aims to complete by the end of July 2020. Two of them focus on some theoretical (relation between echo time and scrambling time) and phenomenological (quasi-normal modes and echoes) aspects of horizonless compact objects which are motivated by quantum gravity corrections at the horizon scale. Another project is aimed to find an answer to the question; which is more fundamental between the bound on entropy and the bound on chaos in thermal quantum systems? At the same time, there are other works in progress; on causality, Hamiltonian formulation and non-singular solution in nonlocal field theory (gravity).
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Report
(1 results)
Research Products
(2 results)