SEMINAR

What can we learn from Spontaneous Lorentz Violation?

Prof. Jon Chkareuli

(Inst. of Phys., Tbilisi & Ilia State Uni., Georgia)

Sala P9, IST, Pavilhão de Matemática
Thursday, September 30th, 2010 at 04:00 PM

Abstract

We argue that the spontaneous Lorentz invariance violation (SLIV) in general vector (tensor) field theories may lead to an appearance of massless Nambu-Goldstone modes which are identified with photons and other gauge fields in the Standard Model, as well as with gravitons in General Relativity. Actually, the SLIV leads to an emergence of gauge invariance both in Abelian and non-Abelian type theories, and diffeomorphism invariance in GR. At low energies, they all are physically indistinguishable from a conventional Lorentz invariant QED, SM and GR theories. However, the physical Lorentz violation inevitably appears if this emergent gauge symmetry is further broken, though slightly, by some high-dimensional terms induced by gravity at very small distances. For the SLIV scale comparable with the Planck scale the Lorentz violation is expected to become directly observable at present energies thus leading to a plethora of observable Lorentz and CPT breaking effects which should manifest themselves in particle physics, astrophysics and cosmology. Some latest developments based on the recent works with R.Mohapatra (Maryland) and H.Nielsen (NBI) are discussed.