We simplify the warp drive space-time so that it becomes stationary and the distorsion becomes one-dimensional and static. We use this simplified warp drive space-time as a background for a photon field. We shall especially use the Drummond&Hathrell action in order to investigate the velocity effects on photons in this background. Finally, we discuss the limitations of this model. ∗e-mail: C.R....

We demonstrate that the four high-frequency QPOs observed in GRS 1915+105 can be interpreted as the oscillation modes on disks that non-linearly and resonantly interact with a warp. The warp is assumed to be a low-frequency global pattern on the disk. This identification suggests that the relevant mass, M , and spin parameter, a, are M = 13–14M⊙ and a= 0–0.15.

In five-dimensional supergravity, an exact solution of BPS wall is found for a gravitational deformation of the massive Eguchi-Hanson nonlinear sigma model. The warp factor decreases for both infinities of the extra dimension. Thin wall limit gives the Randall-Sundrum model without fine-tuning of input parameters. We also obtain wall solutions with warp factors which are flat or increasing in o...