English

Constant H field, cosmology and faster than light solitons

High Energy Physics - Theory 2007-05-23 v2

Abstract

We analyze the possibility of having a constant spatial NS-NS field, H123H_{123}. Cosmologically, it will act as stiff matter, and there will be very tight constraints on the possible value of H123H_{123} today. However, it will give a noncommutative structure with an {\em associative} star product of the type θij=αϵijkxk\theta^{ij}=\alpha \epsilon^{ijk} x^k. This will be a fuzzy space with constant radius slices being fuzzy spheres. We find that gauge theory on such a space admits a noncommutative soliton with galilean dispersion relation, thus having speeds arbitrarily higher than c. This is the analogue of the Hashimoto-Itzhaki construction at constant θ\theta, except that one has fluxless solutions of arbitrary mass. A holographic description supports this finding. We speculate thus that the presence of constant (yet very small) H123H_{123}, even though otherwise virtually undetectable could still imply the existence of faster than light solitons of arbitrary mass (although possibly quantum-mechanically unstable). The spontaneous Lorentz violation given by H123H_{123} is exactly the same one already implied by the FRW metric ansatz.

Keywords

Cite

@article{arxiv.hep-th/0601182,
  title  = {Constant H field, cosmology and faster than light solitons},
  author = {Horatiu Nastase},
  journal= {arXiv preprint arXiv:hep-th/0601182},
  year   = {2007}
}

Comments

30 pages, latex, references added