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An upper limit on the stochastic gravitational-wave background of cosmological origin

Abstract

A stochastic background of gravitational waves is expected to arise from a superposition of a large number of unresolved gravitational-wave sources of astrophysical and cosmological origin. It should carry unique signatures from the earliest epochs in the evolution of the Universe, inaccessible to standard astrophysical observations1. Direct measurements of the amplitude of this background are therefore of fundamental importance for understanding the evolution of the Universe when it was younger than one minute. Here we report limits on the amplitude of the stochastic gravitational-wave background using the data from a two-year science run of the Laser Interferometer Gravitational-wave Observatory2 (LIGO). Our result constrains the energy density of the stochastic gravitational-wave background normalized by the critical energy density of the Universe, in the frequency band around 100 Hz, to be <6.9 × 10-6 at 95% confidence. The data rule out models of early Universe evolution with relatively large equation-of-state parameter3, as well as cosmic (super)string models with relatively small string tension4 that are favoured in some string theory models5. This search for the stochastic background improves on the indirect limits from Big Bang nucleosynthesis1,6 and cosmic microwave background7 at 100 Hz.

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Figure 1: Sensitivities of LIGO interferometers.
Figure 2: Comparison of different SGWB measurements and models.
Figure 3: Constraining early Universe evolution.
Figure 4: Models involving cosmic strings.
Figure 5: Pre-Big-Bang models.

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References

  1. Maggiore, M. Gravitational wave experiments and early universe cosmology. Phys. Rep. 331, 283–367 (2000)

    Article  ADS  Google Scholar 

  2. Abbott, B. et al. Detector description and performance for the first coincidence observations between LIGO and GEO. Nucl. Instrum. Meth. A 517, 154–179 (2004)

    Article  CAS  ADS  Google Scholar 

  3. Boyle, L. & Buonanno, A. Relating gravitational wave constraints from primordial nucleosynthesis, pulsar timing, laser interferometers, and the CMB: implications for the early universe. Phys. Rev. D 78, 043531 (2008)

    Article  ADS  Google Scholar 

  4. Siemens, X., Mandic, V. & Creighton, J. Gravitational-wave stochastic background from cosmic strings. Phys. Rev. Lett. 98, 111101 (2007)

    Article  ADS  Google Scholar 

  5. Sarangi, S. & Tye, S. H. H. Cosmic string production towards the end of brane inflation. Phys. Lett. B 536, 185–192 (2002)

    Article  CAS  ADS  Google Scholar 

  6. Allen, B. The stochastic gravity-wave background: sources and detection. Preprint at &lt;http://arXiv.org/abs/grqc/9604033&gt; (1996)

  7. Smith, T. L., Pierpaoli, E. & Kamionkowski, M. A new cosmic microwave background constraint to primordial gravitational waves. Phys. Rev. Lett. 97, 021301 (2006)

    Article  ADS  Google Scholar 

  8. Allen, B. & Romano, J. Detecting a stochastic background of gravitational radiation: signal processing strategies and sensitivities. Phys. Rev. D 59, 102001 (1999)

    Article  ADS  Google Scholar 

  9. Starobinskii, A. A. Spectrum of relict gravitational radiation and the early state of the universe. JETP Lett. 30, 682–685 (1979)

    ADS  Google Scholar 

  10. Bar-Kana, R. Limits on direct detection of gravitational waves. Phys. Rev. D 50, 1157–1162 (1994)

    Article  CAS  ADS  Google Scholar 

  11. Brustein, R. et al. Relic gravitational waves from string cosmology. Phys. Lett. B 361, 45–51 (1995)

    Article  CAS  ADS  MathSciNet  Google Scholar 

  12. Buonanno, A. et al. Spectrum of relic gravitational waves in string cosmology. Phys. Rev. D 55, 3330–3336 (1997)

    Article  CAS  ADS  Google Scholar 

  13. Mandic, V. & Buonanno, A. Accessibility of the pre-big-bang models to LIGO. Phys. Rev. D 73, 063008 (2006)

    Article  ADS  Google Scholar 

  14. Apreda, R. et al. Gravitational waves from electroweak phase transitions. Nucl. Phys. B 631, 342–368 (2002)

    Article  ADS  Google Scholar 

  15. Kibble, T. W. B. Topology of cosmic domains and strings. J. Phys. A 9, 1387–1398 (1976)

    Article  ADS  Google Scholar 

  16. Damour, T. & Vilenkin, A. Gravitational radiation from cosmic (super)strings: bursts, stochastic background, and observational windows. Phys. Rev. D 71, 063510 (2005)

    Article  ADS  Google Scholar 

  17. Regimbau, T. & de Freitas Pacheco, J. A. Gravitational wave background from magnetars. Astron. Astrophys. 447, 1–8 (2006)

    Article  ADS  Google Scholar 

  18. Regimbau, T. & de Freitas Pacheco, J. A. Cosmic background of gravitational waves from rotating neutron stars. Astron. Astrophys. 376, 381–385 (2001)

    Article  ADS  Google Scholar 

  19. Acernese, F. et al. Status of Virgo. Class. Quant. Grav. 25, 114045 (2008)

    Article  ADS  Google Scholar 

  20. Willke, B. et al. The GEO-HF project. Class. Quant. Grav. 23, S207–S214 (2006)

    Article  Google Scholar 

  21. Bennet, C. L. et al. First-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: preliminary maps and basic results. Astrophys. J. 148 (Suppl.). 1–28 (2003)

    Article  ADS  Google Scholar 

  22. Abbott, B. et al. Searching for a stochastic background of gravitational waves with the Laser Interferometer Gravitational-Wave Observatory. Astrophys. J. 659, 918–930 (2007)

    Article  CAS  ADS  Google Scholar 

  23. Cyburt, R. H. et al. New BBN limits on physics beyond the standard model from 4He. Astropart. Phys. 23, 313–323 (2005)

    Article  ADS  Google Scholar 

  24. Grishchuk, L. P. & Sidorov, Yu. V. Squeezed quantum states of relic gravitons and primordial density fluctuations. Phys. Rev. D 42, 3413–3421 (1990)

    Article  CAS  ADS  MathSciNet  Google Scholar 

  25. Advanced LIGO Team. Advanced LIGO reference design. LIGO preprint at &lt;http://www.ligo.caltech.edu/docs/M/M060056-10.pdf&gt; (2007)

  26. Bender, P. L. & Danzmann, K. & the LISA study team . Laser Interferometer Space Antenna for the Detection and Observation of Gravitational Waves: Pre-Phase A Report 2nd edn (MPQ233, Max-Plank Institut für Quantenoptik, 1998)

    Google Scholar 

  27. Jenet, F. A. et al. Upper bounds on the low-frequency stochastic gravitational wave background from pulsar timing observations: current limits and future prospects. Astrophys. J. 653, 1571–1576 (2006)

    Article  ADS  Google Scholar 

  28. Komatsu, E. et al. Five-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: cosmological interpretation. Astrophys. J. 180 (Suppl.). 330–376 (2009)

    Article  Google Scholar 

  29. Siemens, X. et al. Size of the smallest scales in cosmic string networks. Phys. Rev. D 66, 043501 (2002)

    Article  ADS  Google Scholar 

  30. Siemens, X. et al. Gravitational wave bursts from cosmic (super)strings: quantitative analysis and constraints. Phys. Rev. D 73, 105001 (2006)

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We acknowledge the support of the United States National Science Foundation for the construction and operation of the LIGO Laboratory, the Science and Technology Facilities Council of the United Kingdom, the Max Planck Society, and the State of Niedersachsen/Germany for support of the construction and operation of the GEO600 detector, and the Italian Istituto Nazionale di Fisica Nucleare and the French Centre National de la Recherche Scientifique for the construction and operation of the Virgo detector. We also acknowledge the support of the research by these agencies and by the Australian Research Council, the Council of Scientific and Industrial Research of India, the Istituto Nazionale di Fisica Nucleare of Italy, the Spanish Ministerio de Educacion y Ciencia, the Conselleria d'Economia Hisenda i Innovacio of the Govern de les Illes Balears, the Royal Society, the Scottish Funding Council, the Scottish Universities Physics Alliance, The National Aeronautics and Space Administration, the Carnegie Trust, the Leverhulme Trust, the David and Lucile Packard Foundation, the Research Corporation, and the Alfred P. Sloan Foundation.

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Correspondence to V. Mandic.

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The LIGO Scientific Collaboration & The Virgo Collaboration. An upper limit on the stochastic gravitational-wave background of cosmological origin. Nature 460, 990–994 (2009). https://doi.org/10.1038/nature08278

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