Europhys. Lett.
Volume 64, Number 5, December 2003
Page(s) 641 - 646
Section The physics of elementary particles and fields
Published online 01 November 2003
DOI: 10.1209/epl/i2003-00276-4
Europhys. Lett., 64 (5) , pp. 641-646 (2003)

Noncommutative electrodynamics and ultra-high-energy gamma rays

P. Castorina1, 2 and D. Zappalà2, 1

1  Dipartimento di Fisica, Università di Catania Via S. Sofia 64, I-95123, Catania, Italy
2  INFN, Sezione di Catania - Via S. Sofia 64, I-95123, Catania, Italy

(Received 28 July 2003; accepted in final form 1 October 2003)

Plane waves in noncommutative classical electrodynamics (NCED) have a peculiar dispersion relation. We investigate the kinematical conditions on this deformed "mass shell" which come from ultra-high-energy gamma rays and discuss noncommutative dynamical effects on the gamma absorption by the infrared background and on the intrinsic spectrum. Finally we note that in NCED there is a strong correlation between the modified dispersion relation and the presence of dynamical effects in electromagnetic phenomena such as in the case of the synchrotron radiation. From this point of view, the limits on the typical energy scale of the violation of Lorentz invariance obtained by deformed dispersion relations and by assuming undeformed dynamical effects should be taken with some caution.

11.10.Nx - Noncommutative field theory.
95.85.Pw - $\gamma$-ray.
96.40.-z - Cosmic rays.

© EDP Sciences 2003