Matt Visser

TL;DR: In this article, a general version of the nonlinear Schrodinger equation with a 3-tensor position-dependent mass and arbitrary nonlinearity is considered, and it is shown that at low momenta linearized excitations of the phase of the condensate wavefunction obey a (3+1)-dimensional d'Alembertian equation coupling to a generic effective metric that is generic, and depends algebraically on the background field.

TL;DR: In this paper, the compatibility between faster-than-c propagation and the fundamental principles of relativity and causality is investigated, and the Scharnhorst effect is shown to be the most plausible candidate for a physically sound realization of these phenomena.

TL;DR: It is demonstrated in full generality that stability of the worm hole is equivalent to choosing suitable properties for the exotic material residing on the wormhole throat.

TL;DR: In this paper, the authors show that the strong energy condition (SEC) is violated at some time between the epoch of galaxy formation and the present, which implies that no possible combination of {ital {open_quotes}normal{close-quotes}} matter is capable of fitting the observational data.

TL;DR: In this article, it was shown that a non-minimally coupled scalar field with a positive curvature coupling ξ>0 can easily violate all the standard energy conditions, up to and including the averaged null energy condition (ANEC).