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郭碩鴻講座二十(11月5日10:00-12:00)

報告人: 
龚云贵 教授 (华中科技大学)
題目: 
引力波干涉仪的频率响应The frequency response of gravitational wave interferometers
地點: 
十友堂300
時間: 
11月5日上午10:00-12:00

主持人:張宏浩教授

報告簡介:Gravitational waves are perturbations of the metric of space-time. Six polarizations are possible, although general relativity predicts that only two such polarizations, tensor plus and tensor cross are present for gravitational waves. The detection of extra polarization states is the smoking gun for the modification of general relativity in strong and nonlinear regime. In this talk, we discuss the antenna response to all the six polarizations and derive the analytical formulas which are valid for any equal-arm interferometric gravitational-wave detectors without optical cavities in the arms. We find that the response function averaged over the source direction and polarization angle decreases at high frequencies which deteriorates the signal-to-noise ratio registered in the detector. Space-based gravitational wave detectors cannot keep rigid structures and precise arm length equality, so the precise equality of detector arms which is required in a ground-based interferometer to cancel the overwhelming laser noise is impossible. The time-delay interferometry method is applied to unequal arm lengths to cancel the laser frequency noise. We give analytical formulas of the averaged response functions for tensor, vector, breathing and longitudinal polarizations in different TDI combinations, and obtain their asymptotic behaviors. We also use LISA and TianQin as examples to show sensitivity curves for all six possible polarizations.

報告人簡介:龔雲貴,華中科技大學二級教授、博士生導師,美國貝勒大學客座教授。國際廣義相對論和引力學會終身會員,亞太物理學會天體物理、引力和宇宙學分會執委,中國引力與相對論天體物理學會秘書長。1991年畢業于華中理工大學(現華中科技大學)並獲得學士學位,1994年在中國科學院理論物理研究所獲得碩士學位,2001年獲得美國德克薩斯州立大學奧斯汀分校博士,師從SU(3)理論創始者之一、美國科學院院士Neeman教授。在PRL等國際高水平學術期刊上發表了100多篇SCI學術論文,發表的學術論文在高能數據庫InSpires中被引用4500余次,其中12篇論文被引用超過100次,h指數爲35,入選了全球前10萬科學家。主持了包括國家自然科學基金重點項目在內的多項國家及省部級科研項目。先後榮獲教育部新世紀優秀人才計劃、中國僑界雙百貢獻獎(創新人才獎)、重慶市自然科學一等獎等獎項及榮譽稱號。現主要從事相對論引力與宇宙學的研究工作。