A limit on the variation of the speed of light arising from quantum gravity effects
2009 (English)In: Nature, ISSN 0028-0836, Vol. 462, no 7271, 331-334 p.Article in journal (Refereed) Published
A cornerstone of Einstein's special relativity is Lorentz invariance-the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon-energy. While special relativity assumes that there is no fundamental length-scale associated with such invariance, there is a fundamental scale (the Planck scale, l(Planck) approximate to 1.62 x 10(-33) cm or E-Planck = M(Planck)c(2) approximate to 1.22 x 10(19) GeV), at which quantum effects are expected to strongly affect the nature of space-time. There is great interest in the (not yet validated) idea that Lorentz invariance might break near the Planck scale. A key test of such violation of Lorentz invariance is a possible variation of photon speed with energy(1-7). Even a tiny variation in photon speed, when accumulated over cosmological light-travel times, may be revealed by observing sharp features in gamma-ray burst (GRB) light-curves(2). Here we report the detection of emission up to similar to 31GeV from the distant and short GRB090510. We find no evidence for the violation of Lorentz invariance, and place a lower limit of 1.2E(Planck) on the scale of a linear energy dependence (or an inverse wavelength dependence), subject to reasonable assumptions about the emission (equivalently we have an upper limit of l(Planck)/1.2 on the length scale of the effect). Our results disfavour quantum-gravity theories(3,6,7) in which the quantum nature of space-time on a very small scale linearly alters the speed of light.
Place, publisher, year, edition, pages
2009. Vol. 462, no 7271, 331-334 p.
gamma-ray bursts, high-energy, violation, emission, photons, lorentz, tests, foam
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-18968DOI: 10.1038/nature08574ISI: 000271899300039ScopusID: 2-s2.0-70450278871OAI: oai:DiVA.org:kth-18968DiVA: diva2:337015
QC 201005252010-08-052010-08-052012-02-23Bibliographically approved