Sunday, November 25, 2007

Progress

2002

"I have shown here that there exist relativistic theories in which the GZK cutoff is shifted significantly upward (enough to explain the cosmic-ray puzzle) but there is no preferred class of inertial observers."

~ Giovanni Amelino-Camelia, "Kinematical solution of the UHE-cosmic-ray puzzle without a preferred class of inertial observers", Int.J.Mod.Phys. D12 (2003) 1211-1226, astro-ph/0209232, p. 7

2007

"What could instead accomodate exactly the situation where there is no GZK anomaly but we do find anomalous in vacua despersion? Well [...] you basically could go to the direction I prososed a few years ago, which is allow for departures from Lorentz symmetry but without the emergence of a preferred frame [...] No preferred frame. These turn out to be a much softer class [..] of departures from standard Poincare symmetry [...] They are unable [...] to provide an observably large GZK threshold anomaly.

Despite of what is said in many Doubly Special Relativity papers [...] That's not possible."

~ Giovanni Amelino-Camelia, talk given at the workshop on Experimental Search for Quantum Gravity, pirsa:07110057, min. 26:23

5 comments:

  1. http://www.calphysics.org/research.html

    That theory could work and should work doesn't mean that theory will work. If theory doesn't work versus observation, it's wrong.

    http://www.mazepath.com/uncleal/horse.htm

    ReplyDelete
  2. So this means that DSR is dead?

    ReplyDelete
  3. No, it means that a modification of the standard model which preserves observer independence and which becomes important at Planckian energies can not cause a significant shift in thresholds that are at a GeV in the center of mass frame.

    ReplyDelete
  4. BTW, Amelino-Camelia is in this week's Nature (450, 6 December 2007, p 801-803): Relativity: Still special.

    Best, Stefan

    ReplyDelete

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