RUI: Stochastic Background Searches with the LIGO and ALLEGRO Detectors

Loyola University New Orleans, New Orleans LA

Investigators

Abstract

The Laser Interferometer Gravitational wave Observatory (LIGO) is currently in a phase of sci- entific data collecting interspersed with commissioning activities that are incrementally improving the sensitivities. The ALLEGRO resonant mass gravitational wave detector operated by Louisiana State University in Baton Rouge is located about 40 kilometers from the LIGO Livingston Observatory (LLO). The detector has undergone major renovation since being moved to a new laboratory and has also had periods of data collection interspersed with this activity. The proximity of the LLO and ALLEGRO detectors allows for a unique opportunity in the search for gravitational radiation. The primary focus of this research is to exploit this proximity to search for a stochastic background of gravitational waves. ALLEGRO has the ability to rotate the detector with a minimum of disruption. This will allow a modulation of the signal by aligning and mis-aligning the detector with the LLO interferometer arms. This allows for the removal of any correlated noise that does not have the expected quadrupolar spatial dependence of the gravitational radiation. This project represents the continuation of research to pursue the data analysis challenges in searching for stochastic background of gravitational waves with the ALLEGRO-LLO pair of detectors as a complement to other such searches in LIGO. If our current understanding of the Universe is correct, there almost certainly exists a stochastic background of gravitational waves at some level, originating as a remnant of inflation, a phase transition in the early universe, or from the confusion limit of a large number of discrete sources. An observation or upper limit placed on such a background brings us new information about the Universe. The project will have an impact on the educational environment at Loyola University New Orleans, a primarily undergraduate institution in Louisiana. This project will maintain a vibrant research activity at Loyola, while incorporating undergraduate students as research assistants.