Session E11: Invited Session: Detecting GWs from the Ground and in Space

Hearing Voices in the Dark: Probing the gravitational wave Cosmos from space

The advent of broadband gravitational wave detection using laser interferometry is a transformative technology that for the first time makes the gravitational spectrum a tool for astronomers to probe the Cosmos. Interferometric observatories in space, with armlengths millions of kilometers long, will be sensitive to low-frequency radiation in the millihertz regime of the gravitational wave spectrum. This part of the spectrum is alive with signals from massive black hole binaries, interacting binaries in the galaxy, the capture of stellar mass objects by supermassive black holes in galactic nuclei, and possibly stochastic backgrounds of gravitational radiation of cosmological origin. In this talk, we will discuss the science that low frequency gravitational observations of the Cosmos will reveal.   

Atom Interferometry for Detection of Gravitational Waves: Progress and Prospects

Gravitational wave astronomy promises to provide a new window into the universe, collecting information about astrophysical systems and cosmology that is difficult or impossible to acquire by other methods. Detector designs based on atom interferometry offer a number of advantages over traditional approaches, including access to conventionally inaccessible frequency ranges and substantially reduced antenna baselines. Atomic physics techniques also make it possible to build a gravitational wave detector with a single linear baseline, potentially offering advantages in cost and design flexibility. In support of these proposals, recent progress in long baseline atom interferometry has enabled observation of matter wave interference with atomic wavepacket separations exceeding 10 cm and interferometer durations of more than 2 seconds. These results are obtained in a 10-meter drop tower incorporating large momentum transfer atom optics. This approach can provide ground-based proof-of-concept demonstrations of many of the technical requirements of both terrestrial and satellite gravitational wave detectors.   

LIGO and the network of terrestrial gravitational wave detectors

Gravitational Wave detectors based on the idea of measuring GW-induced strains via laser interferometry are poised to make first detections in the next few years. This talk will give an overview of this approach to developing a new astrophysical window, using the US LIGO effort as the example. The basic detection mechanism --- and its limitations --- will be described, and the interesting upper limits and non-detections to date with the initial detectors reviewed. The second generation of instruments, exemplified by Advanced LIGO, is just coming on line, and those instruments and the astrophysics potential with the more sensitive detectors will be discussed. Lastly, means to move beyond the Advanced LIGO sensitivity will be sketched.~