Related papers: Spontaneous Lorentz symmetry breaking and cosmolog…

This paper has been withdrawn at the request of one of the authors.

This paper has been withdrawn.

This paper has been withdrawn by the author, since one of the key results duplicates existing work, as pointed out by a reader. I am currently revising the manuscript.

The paper was withdrawn by the authors.

This paper has been withdrawn by the author, due a crucial error in Eq. 6.

This paper has been withdrawn by the author, since the author does not have enough time to answer every questions on this result.

This paper has been withdrawn for the reasons mentioned in the Comments.

This article has been removed. It has been superseded by gr-qc/0506097.

This paper has been withdrawn by the author, due an error in computing the invariance of the so(4,1) and so(3,2) "inner product."

This paper has been withdrawn by the author because Lemma 3 is incorrect. This mistake is crucial in this paper.

This paper has been withdrawn by the author due to a crucial sign error in equation 1.

This paper has been withdrawn by the author since the comments have been withdrawn.

A nonlocal interaction is not necessarily expressed by the deformation of commutators, so the paper is withdrawn.

This paper has been withdrawn by the author due to imprecisions which must conduce to wrong results.

This paper has been withdrawn by the authors. The authors have now written two separate papers, one theoretical (A. Smerzi, A. Trombettoni, P. G. Kevrekidis, and A. R. Bishop Phys. Rev. Lett. 89, 170402 (2002)) and one experimental (F. S.…

The paper has been withdrawn by the author.

The paper has been withdrawn

This paper has been withdrawn by the authors due to some fatal errors in the analysis.

This paper has been withdrawn by the author due to an error.

This paper has been withdrawn. It will be split into two separate papers. New results will be added in both papers.