本帖最後由 iheby 於 2017-6-17 22:33 編輯
BMS對稱陪集 - 重力子作為南-戈玻色子的一種 @香港科技大學 賽馬會高等研究院
Seminar:- Coset for BMS: Graviton as a Nambu-Goldstone Boson
It has been known that graviton can be thought of as a Nambu-Goldstone (NG) boson for spontaneously broken GL(4) symmetry, which is a part of large gauge transformations associated to general covariance. In this interpretation, all the components of the metric are identified with NG bosons, so that these NG modes include gauge degrees of freedom in addition to the two physical helicity modes of graviton. In this talk, the speaker will revisit such property of graviton based on the Bondi-Metzner-Sachs (BMS) symmetry, an infinite dimensional symmetry of asymptotically flat spacetimes. In particular, he will illustrate that the viewpoint of asympotics resolves the mismatch between the number of broken symmetries and physical helicity modes.
時間：2017.06.13(二) 14:00
地點：香港科技大學 李兆基校園 盧家驄薈萃樓4樓 高研院4042室
講者：野海俊文 教授 Prof. Toshifumi Noumi (日本神戶大學)
語言：英語
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從宇宙膨漲-規範場交互作用來的原初重力波 @香港科技大學 賽馬會高等研究院
Seminar:- Primordial Gravitational Waves from an Inflaton-Gauge Interaction
In this talk, the speaker will focus on a gauge field interacting with the inflaton through an exponential type coupling function. It is known that such a coupling is ubiquitous from higher dimensional fundamental theory. He will show that the gauge field grows at the later stage of inflaton due to the interaction. Consequently, high-frequency gravitational waves are induced by such gauge field production.
時間：2017.06.13(二) 15:00
地點：香港科技大學 李兆基校園 盧家驄薈萃樓4樓 高研院4042室
講者：伊藤飛鳥 博士 Dr. Asuka Ito (日本神戶大學)
語言：英語
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從修整重力的暗物質新觀點 @香港科技大學 賽馬會高等研究院
Seminar:- New Views on Dark Matter from Modified Gravity
In this talk, the speaker will discuss a scenario that the dark matter emerge from higher dimensional embedding of the 4-dimensional spacetime, which the dark matter density can be determined by the Hubble constant, local gravity and the visible matter content. Her approach may give a new viewpoint for Verlinde’s emergent gravity from higher dimensions. The speaker will also comment on the some phenomenological implications of this type of models, including gravitational wave solutions and MOND limit.
時間：2017.06.15(四) 13:45
地點：香港科技大學 李兆基校園 盧家驄薈萃樓4樓 高研院2042室
講者：Dr Sichun Sun (國立臺灣大學)
語言：英語
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