Derivation of a Vacuum Refractive Index in a Stringy Space-Time Foam Model

Simple item page
dc.creatorEllis, John
dc.creatorMavromatos, N. E.
dc.creatorNanopoulos, D. V.
dc.date2008-04-22
dc.date.accessioned2026-07-07T11:50:07Z
dc.date.available2026-07-07T11:50:07Z
dc.descriptionIt has been suggested that energetic photons propagating in vacuo should experience a non-trivial refractive index due to the foamy structure of space-time induced by quantum-gravitational fluctuations. The sensitivity of recent astrophysical observations, particularly of AGN Mk501 by the MAGIC Collaboration, approaches the Planck scale for a refractive index depending linearly on the photon energy. We present here a new derivation of this quantum-gravitational vacuum refraction index, based on a stringy analogue of the interaction of a photon with internal degrees of freedom in a conventional medium. We model the space-time foam as a gas of D-particles in the bulk space-time of a higher-dimensional cosmology where the observable Universe is a D3-brane. The interaction of an open string representing a photon with a D-particle stretches and excites the string, which subsequently decays and re-emits the photon with a time delay that increases linearly with the photon energy and is related to stringy uncertainty principles. We relate this derivation to other descriptions of the quantum-gravitational refractive index in vacuo.
dc.description8 pages, 3 eps figures
dc.identifierhttps://arxiv.org/abs/0804.3566
dc.identifierhttp://arxiv.org/abs/0804.3566
dc.identifierPhys.Lett.B665:412-417,2008
dc.identifierdoi:10.1016/j.physletb.2008.06.029
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/203464
dc.subjectHigh Energy Physics - Theory
dc.subjectAstrophysics
dc.subjectGeneral Relativity and Quantum Cosmology
dc.subjectHigh Energy Physics - Phenomenology
dc.titleDerivation of a Vacuum Refractive Index in a Stringy Space-Time Foam Model
dc.typetext

Files

Collections

arXiv