Research
My research work has to do with the study of some of the most exotic phenomena existing in the Universe such as black holes and neutron stars. These systems are the main targets for ground-based laser interferometers of gravitational radiation. The direct detection of these elusive ripples in the curvature of spacetime, and the wealth of new astrophysical information that can potentially be extracted thereof, is one of the driving motivations of present-day research in relativistic astrophysics.
The use of numerical simulations to understand the dynamics of these astronomical objects is an essential part of my work. The equations governing the dynamics of neutron stars and black holes are an intricate, coupled system of time-dependent partial differential equations, comprising the (general) relativistic (magneto) hydrodynamics equations (see also this link) and the Einstein gravitational field equations. In our group we have developed a general procedure to solve numerically the general relativistic hydrodynamics (and MHD) equations within the framework of the so-called 3+1 formulation of general relativity. These equations are cast in flux-conservative form to take advantage of their hyperbolic mathematical character. All theoretical ingredients needed to build up robust numerical schemes based on the solution of local Riemann problems have been derived. This has allowed for an straightforward implementation of so-called high-resolution shock-capturing (HRSC) schemes, which belong to a class of modern finite-volume methods specifically designed to solve hyperbolic systems of conservation laws.
I have applied HRSC schemes in the numerical modelling of a number of astrophysical scenarios - extragalactic jets, accretion disks, wind accretion on to black holes, gravitational stellar core collapse to neutron stars and black holes, binary neutron star mergers, and pulsations and instabilities of relativistic stars. In the publications section of these pages you can find pointers to further (technical) reading on these topics.