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CAS Key Laboratory of Theoretical Physics
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Institute of Theoretical Physics
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Chinese Academy of Sciences
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Seminar
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Title
题目
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Gauge Invariance of Scalar Induced Gravitational Waves ( 标量扰动诱导的引力波及其规范不变性) |
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Speaker
报告人
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王赛 副研究员
2009年本科毕业于华中科技大学，2014年博士毕业于中国科学院大学，先后在高能物理所、理论物理所、香港中文大学、日本高能加速器研究机构（KEK）开展引力和宇宙学研究。2019年入职高能物理所。目前致力于引力波宇宙学方面的研究工作。 |
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Affiliation
所在单位
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高能物理所理论物理室 |
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Date
日期
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November 11 (Wednesday) 3:00 pm |
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Venue
地点
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6420 |
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Contact Person
所内联系人
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皮石 |
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Abstract
摘要
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We investigate the gauge invariance of the second order gravitational waves induced by the first order scalar perturbations by following the Lie derivative method. It is shown explicitly that the second order gravitational waves are gauge invariant in the synchronous frame. In the gauge invariant framework, we derive the equation of motion of the second order gravitational waves and show that the second order gravitational waves are sourced from the first order scalar perturbations described well in the gauge invariant Newtonian frame. Since the observables of gravitational waves are measured in the synchronous frame, we define the energy density spectrum of the second order gravitational waves in terms of the gauge invariant synchronous variables. This way guarantees no fictitious tensor perturbations. It is shown that the gauge invariant energy density spectrum of the second order gravitational waves coincides with the one in the Newtonian gauge. |
