Lorentz Invariance Violation from String Theory
Abstract
Description
In this brief, and by no means complete, review I discuss situations in string theory, in which Lorentz Invariance Violation may occur in a way consistent with world-sheet conformal invariance, thereby leading to acceptable, in principle, string backgrounds. In particular, I first discuss spontaneous Lorentz violation in (non supersymmetric) open string field theory. Then, I move onto a discussion of gravity-induced modified dispersion relations in non-critical (Liouville) strings, in the sense of an induced Finsler-like geometry depending on both coordinates and momenta, for string propagation in non-trivial space times (such as D-particle ``foamy situations''). I pay attention to explaining the appearance of bi-metric models from such string theories, which could serve as examples of alternative scenaria to dark matter. Finally, I make some comparisons with similar developments in other contexts, such as critical strings in non-commutative space times, as well as deformed special relativities and theories with reduced Lorentz symmetry, advocated recently, where again Finsler geometry seems to come into play. In this latter respect, I put the emphasis on phenomenology and attempt to answer the question as to whether there is the possibility of experimental disentanglement of the various approaches.
26 pages Latex, uses special macros, three eps figures incorporated. Invited talk at the International Workshop ``From Quantum to Emergent Gravity: Theory and Phenomenology'', SISSA, Trieste (Italy), June 11-15 2007
26 pages Latex, uses special macros, three eps figures incorporated. Invited talk at the International Workshop ``From Quantum to Emergent Gravity: Theory and Phenomenology'', SISSA, Trieste (Italy), June 11-15 2007