讲座：引力波探测器LISA

报告题目：

1. Gravitational Waves and their detection: Laser-interferometers on Earth

2. GW detection in space:  projects of large space-borne laser interferometers

 报告人：A. Ruediger教授，Albert-Einstein-Institute Hannover, Germany

 摘 要：

1. Gravitational waves are a consequence of Einstein’s General Theory of Relativity.  Time-derivatives of the mass quadrupole moment of celestial bodies are the source of such waves.  The waves induce tiny strains in space-time, typically of the order 10^{-21} or less. 

Michelson-type interferometers with arm-lengths in the km range have been constructed to detect such waves, yet without measuring any events.  Therefore, a second generation of such antennas is under construction, with increased sensitivities.  The technologies being pursued are discussed that lead to the desired improvements. 

 2. Gravitational waves of low frequencies (below 1 Hz) cannot be measured by terrestrial detectors, due to many noise contributions in that frequency range.  Laser interferometers in space, with huge arm-lengths, have been proposed and are under active study.  The most prominent of these, LISA, has been studied in a NASA/ESA collaboration.  Its arm-lengths

of  5 million km will allow measuring GWs from cosmological events stemming from distant galaxies and involving massive black holes.  The envisaged sensitivities would allow a deep insight into many cosmological questions.  Other proposed space-borne GW detectors will also be discussed.  The launch of the technology demonstrator mission, the LISA Pathfinder, is within a few years from now.  It will verify the key technologies that are crucial for LISA, but also for other space missions using laser interferometry.

 时间：

1. 2011年05月16日上午10：00点

2. 2011年05月17日上午10：00点

地点：科研楼五层物理所报告厅。