TL;GR : GRTL highlights

Our article on warp drive collapse made it into the Daily Star!

Despite originating in science fiction, warp drives have a concrete description in general relativity, with Alcubierre first proposing a spacetime metric that supported faster-than-light travel. Whilst there are numerous practical barriers to their implementation in real life, including a requirement for negative energy, computationally, one can simulate their evolution in time given an equation of state describing the matter. 

In this work, we studied the signatures arising from a warp drive "containment failure", assuming a stiff equation of state for the fluid. We compute the emitted gravitational-wave signal and track the energy fluxes of the fluid. Apart from its rather speculative application to the search for extraterrestrial life in gravitational-wave detector data, this work is interesting as a study of the dynamical evolution and stability of spacetimes that violate the null energy condition. Our work highlights the importance of exploring strange new spacetimes, to (boldly) simulate what no one has seen before.

Our article on dynamics friction from scalar dark matter was an editor's suggestions in PRD Letters!

In this work we used numerical simulations of scalar field dark matter evolving on a moving black hole background to confirm the regime of validity of (semi)analytic expressions derived from first principles for both dynamical friction and momentum accretion in the relativistic regime. We covered both small and large clouds (relative to the de Broglie wavelength of the scalars), and light and heavy particle masses (relative to the black hole size). In the case of a small dark matter cloud, the effect of accretion is a non-negligible contribution to the total force on the black hole, even for small scalar masses. We confirm that this momentum accretion transitions between two regimes (wave and particlelike) and we identify the mass of the scalar at which the transition between regimes occurs.