New constraints on Planck-scale Lorentz violation in QED from the Crab Nebula

Abstract

Abstract. We set constraints on O(E/M ) Lorentz Violation in QED in an effective field theory framework. A major consequence of such assumptions is the modification of the dispersion relations for electrons/positrons and photons, which in turn can affect the electromagnetic output of astrophysical objects. We compare the information provided by multiwavelength observations with a full and self-consistent computation of the broad-band spectrum of the Crab Nebula. We cast constraints of order 10 −5 at 95% confidence level on the lepton Lorentz Violation parameters.

Lorentz violation and ultrahigh-energy photons

“…For the coefficients of LIV terms linearly suppressed with the Planck scale values larger than ∼ 10 −5 for electrons and positrons are currently ruled out by the observation of synchrotron radiation from the Crab Nebula [8]. We find that the observation of photons above ≃ 10 19 eV would rule out that any one of the three LIV coefficients for electrons, positrons and photons has absolute value > ∼ 10 −14 .…”

On Modified Dispersion Relations and the Chandrasekhar Mass Limit

“…[3]), the calculation of the Chandrasekhar mass limit using MDR is straightforward. The mass limit is raised or lowered according to the sign of the modification.…”

“…For an electron this occurs at an energy scale of 3 m 2 e M P ∼ 10 TeV -significantly below the Planck scale. While these energy scales are beyond terrestrial experiments, astrophysical processes at these energy scales effectively constrain the cubic modifications [3][4][5].…”

Gamma-ray polarization constraints on Planck scale violations of special relativity

“…This effect is known as vacuum birefringence (VB). Recently η ± have been constrained to have a magnitude less than 10 −5 at 95% confidence level (CL) by a detailed analysis of the synchrotron component of the Crab Nebula (CN) broadband spectrum [5], while the constraint |ξ | 2 × 10 −7 has been obtained by [6] considering the absence of VB effects during the propagation of optical/UV polarized light from Gamma-Ray Bursts (GRB). There are also preliminary indications, based on an analysis of the photon fraction in Ultra-High-Energy Cosmic Rays, that these coefficients might be less than 10 −14 [7,8,9].…”