Carlos Barceló

TL;DR: Analogous gravity is a research programme which investigates analogues of general relativistic gravitational fields within other physical systems, typically but not exclusively condensed matter systems, with the aim of gaining new insights into their corresponding problems.

TL;DR: The tension between quantum physics and general relativity is one of the great problems facing physics at the turn of the millennium as mentioned in this paper, and it has become increasingly obvious that the difficulties are more widespread: there are already serious problems of deep and fundamental principle at the semi-classical level.

TL;DR: In this article, it was shown that at low momenta linearized excitations of the phase of the condensate wavefunction obey a d'Alembertian equation coupling to a ( 3+1 )-dimensional Lorentzian-signature effective metric that is generic, and depends algebraically on the background field.

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 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).