Considering a higher dimensional Lorentz group as the tangent symmetry, we unify gravity and gauge interactions in a natural way. The spin connection of the gauged Lorentz group is then responsible for both gravity and gauge fields, and the action for the gauged fields becomes part of the spin curvature squared. The realistic group which unifies all known particles and interactions is the SO(1,...

It has been almost one hundred years since Einstein formulated his special theory of relativity in 1905. He showed that the basic space-time symmetry is dictated by the Lorentz group. It is shown that this group of Lorentz transformations is not only applicable to special relativity, but also constitutes the scientific language for optical sciences. It is noted that coherent and squeezed states...

The inelastic Lorentz gas in cooling states is studied. It is found that the inelastic Lorentz gas is localized and that the mean square displacement of the inelastic Lorentz gas obeys a power of a logarithmic function of time. It is also found that the scaled position distribution of the inelastic Lorentz gas has an exponential tail, while the distribution is close to the Gaussian near the pea...

Recently, first limits on putative Lorentz invariance violation coefficients in the pure gravity sector were determined by the reanalysis of short-range gravity experiments. Such experiments search for new physics at sidereal frequencies. They are not, however, designed to optimize the signal strength of a Lorentz invariance violation force; in fact the Lorentz violating signal is suppressed in...

Superalgebras including generators having spins up to two and realisable as tangent vector fields on Lorentz covariant generalised superspaces are considered. The latter have a representation content reminiscent of configuration spaces of (super)gravity theories. The most general canonical supercommutation relations for the corresponding phase space coordinates allowed by Lorentz covariance are...

In recent years, there has been a growing interest in testing Lorentz and CPT symmetry. This is due to both theoretical developments as well as improved experimental capabilities. For example, it has been shown that string theory can lead to violations of CPT and Lorentz symmetry. This is because strings are nonpointlike and have nonlocal interactions. They can therefore evade the CPT theorem. ...

A V-duality conjecture for noncommutative open string theories (NCOS) that result from decoupling D-branes in Lorentz-boost related backgrounds was put forward recently in hepth/0006013. The aim of this paper is to test the Galilean nature of this conjecture in the gravity dual setup. We start with an (F, D3) bound state Lorentz-boosted along one D3-brane direction perpendicular to the F-string...

We review the main theoretical motivations and observational constraints on Planck scale suppressed violations of Lorentz invariance. After introducing the problems related to the phenomenological study of quantum gravitational effects, we discuss the main theoretical frameworks within which possible departures from Lorentz invariance can be described. In particular, we focus on the framework o...

Lorentz gas as a typical distribution of velocities for more than a moment. We may take the initial momentary distribution of velocities as conforming to Lorentz, but a moment later, owing to the finite distribution of the condensing wall, the ions there will have a radial distribution of velocity with v V v not equal to zero. With v * V v not equal to zero at the points we cannot make the gas ...

Possibilities for testing Lorentz symmetry using precision experiments with antiprotons in Penning traps and with antihydrogen spectroscopy are reviewed. Estimates of bounds on relevant coefficients for Lorentz violation in the Standard-Model Extension (SME) are considered. THE STANDARD-MODEL EXTENSION Einstein’s General Relativity and the Standard Model of particle physics provide an excellent...