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A strong astrophysical constraint on the violation of special relativity by quantum gravity


Special relativity asserts that physical phenomena appear the same to all unaccelerated observers. This is called Lorentz symmetry and relates long wavelengths to short ones: if the symmetry is exact it implies that space-time must look the same at all length scales. Several approaches to quantum gravity, however, suggest that there may be a microscopic structure of space-time that leads to a violation of Lorentz symmetry. This might arise because of the discreteness1 or non-commutivity2 of space-time, or through the action of extra dimensions3. Here we determine a very strong constraint on a type of Lorentz violation that produces a maximum electron speed less than the speed of light. We use the observation of 100-MeV synchrotron radiation from the Crab nebula to improve the previous limit by a factor of 40 million, ruling out this type of Lorentz violation, and thereby providing an important constraint on theories of quantum gravity.

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  1. Gambini, R. & Pullin, J. Nonstandard optics from quantum spacetime. Phys. Rev. D 59, 124021 (1999)

    ADS  MathSciNet  Article  Google Scholar 

  2. Carroll, S. M., Harvey, J. A., Kostelecky, V. A., Lane, C. D. & Okamoto, T. Noncommutative field theory and Lorentz violation. Phys. Rev. Lett. 87, 141601 (2001)

    ADS  MathSciNet  CAS  Article  Google Scholar 

  3. Burgess, C. P., Cline, J., Filotas, E., Matias, J. & Moore, G. D. Loop-generated bounds on changes to the graviton dispersion relation. J. High Energy Phys. 0203, 043 (2002)

    ADS  Article  Google Scholar 

  4. Myers, R. C. & Pospelov, M. Experimental challenges for quantum gravity. Phys. Rev. Lett. 90, 211601 (2003)

    ADS  MathSciNet  Article  Google Scholar 

  5. Pavlopoulos, T. G. Breakdown of Lorentz invariance. Phys. Rev. 159, 1106–1110 (1967)

    ADS  Article  Google Scholar 

  6. Amelino-Camelia, G. et al. Tests of quantum gravity from observations of gamma-ray bursts. Nature 393, 763–765 (1998)

    ADS  CAS  Article  Google Scholar 

  7. Schaefer, B. Severe limits on variations of the speed of light with frequency. Phys. Rev. Lett. 82, 4964–4966 (1999)

    ADS  CAS  Article  Google Scholar 

  8. Biller, S. D. et al. Limits to quantum gravity effects from observations of TeV flares in active galaxies. Phys. Rev. Lett. 83, 2108–2111 (1999)

    ADS  CAS  Article  Google Scholar 

  9. Kaaret, P. Pulsar radiation and quantum gravity. Astron. Astrophys. 345, L32–L34 (1999)

    ADS  Google Scholar 

  10. Norris, J. P., Bonnell, J. T., Marani, G. F. & Scargle, J. D. GLAST, GRBs, and quantum gravity. Bull. Am. Astron. Soc. 31, 717 (1999)

    ADS  Google Scholar 

  11. Gleiser, R. J. & Kozameh, C. N. Astrophysical limits on quantum gravity motivated birefringence. Phys. Rev. D 64, 083007 (2001)

    ADS  Article  Google Scholar 

  12. Gonzalez-Mestres, L. Cosmological implications of a possible class of particles able to travel faster than light. Nucl. Phys. Proc. Suppl. 48, 131–134 (1996)

    ADS  CAS  Article  Google Scholar 

  13. Coleman, S. & Glashow, S. L. High-energy tests of Lorentz invariance. Phys. Rev. 59, 116008 (1999)

    Google Scholar 

  14. Stecker, F. W. & Glashow, S. L. New tests of Lorentz invariance following from observations of the highest energy cosmic gamma rays. Astropart. Phys. 16, 97–99 (2001)

    ADS  Article  Google Scholar 

  15. Jacobson, T., Liberati, S. & Mattingly, D. TeV astrophysics constraints on Planck scale Lorentz violation. Phys. Rev. D 66, 081302 (2002)

    ADS  Article  Google Scholar 

  16. Jacobson, T., Liberati, S. & Mattingly, D. Threshold effects and Planck scale Lorentz violation: Combined constraints from high energy astrophysics. Phys. Rev. D 67, 124011 (2003)

    ADS  Article  Google Scholar 

  17. Konopka, T. J. & Major, S. A. Observational limits on quantum geometry effects. New J. Phys. 4, 57.1–57.8 (2002)

    Article  Google Scholar 

  18. Amelino-Camelia, G. Improved limit on quantum-spacetime modifications of Lorentz symmetry from observations of gamma-ray blazers. Preprint at 〈〉 (2002).

  19. Jacobson, T., Liberati, S. & Mattingly, D. Comments on ‘Improved limit on quantum-spacetime modifications of Lorentz symmetry from observations of gamma-ray blazars’. Preprint at 〈〉 (2003).

  20. Stecker, F. W. Tests of quantum, gravity and large extra dimensions models using high energy gamma ray observations. Preprint at 〈〉 (2003).

  21. Gonzalez-Mestres, L. Lorentz symmetry violation and acceleration in relativistic shocks. AIP Conf. Proc. 558, 874–877 (2001)

    ADS  CAS  Article  Google Scholar 

  22. Jackson, J. D. Classical Electrodynamics, 3rd edn, 671 (Wiley & Sons, New York, 1998)

    Google Scholar 

  23. Atoyan, A. M. & Aharonian, F. A. On the mechanisms of gamma radiation in the Crab Nebula. Mon. Not. R. Astron. Soc. 278, 525–541 (1996)

    ADS  CAS  Article  Google Scholar 

  24. de Jager, O. C. et al. Gamma-ray observations of the Crab Nebula: A study of the synchro-Compton spectrum. Astrophys. J. 457, 253–266 (1986)

    ADS  Article  Google Scholar 

  25. Hillas, A. H. et al. The Spectrum of TeV gamma rays from the Crab nebula. Astrophys. J. 503, 744–759 (1998)

    ADS  CAS  Article  Google Scholar 

  26. Aloisio, R., Blasi, P., Ghia, P. L. & Grillo, A. F. Probing the structure of space-time with cosmic rays. Phys. Rev. D 62, 053010 (2000)

    ADS  Article  Google Scholar 

  27. Amelino-Camelia, G. Proposal of a second generation of quantum-gravity-motivated Lorentz-symmetry tests: Sensitivity to effects suppressed quadratically by the Planck scale. Preprint at 〈〉 (2003).

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We thank F. A. Aharonian, G. E. Allen, G. Amelino-Camelia and F. Stecker for discussions. This work was supported in part by the NSF.

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Correspondence to T. Jacobson.

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Jacobson, T., Liberati, S. & Mattingly, D. A strong astrophysical constraint on the violation of special relativity by quantum gravity. Nature 424, 1019–1021 (2003).

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