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Upper limits on a stochastic background of gravitational waves
B Abbott1, R Abbott, R Adhikari
1LIGO-California Institute of Technology, Pasadena, California 91125, USA.
Physical Review Letters
|December 31, 2005
Summary
The Laser Interferometer Gravitational-Wave Observatory (LIGO) searched for gravitational wave backgrounds using its third science run data. New upper bounds were set, significantly improving previous limits for a flat spectrum gravitational wave background.
Area of Science:
- Astrophysics
- Cosmology
- Gravitational Wave Astronomy
Background:
- The search for a stochastic background of gravitational radiation is crucial for understanding early universe cosmology and astrophysical processes.
- Previous searches have placed upper limits on the energy density of gravitational waves, but further improvements are needed.
Purpose of the Study:
- To analyze data from the third science run of the Laser Interferometer Gravitational-Wave Observatory (LIGO) to search for a stochastic background of gravitational radiation.
- To establish new upper bounds on the energy density of gravitational waves across different spectral power laws.
Main Methods:
- Analysis of approximately 200 hours of data from the third LIGO science run.
- Utilizing improved sensitivities of all three LIGO interferometers.
- Setting upper limits on gravitational wave energy density for three distinct spectral power laws.
Main Results:
- An upper bound on the energy density for a flat spectrum gravitational wave background was determined to be omega0 < 8.4 x 10(-4) in the 69-156 Hz band.
- This result represents an improvement of approximately 10(5) times compared to previous limits in this frequency range.
- New upper limits were also established for two other spectral power laws.
Conclusions:
- The third LIGO science run has significantly advanced the search for a stochastic gravitational wave background.
- The improved sensitivity allows for more stringent constraints on cosmological models and astrophysical sources of gravitational waves.
- Future observing runs with even greater sensitivity will further probe the gravitational wave universe.
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