Sobre les teories especial i general de la relativitat

Una perspectiva de la teoria de la relativitat per als que no dominen l'aparell matemàtic de la físic

Consideracions fonamentals sobre el postulat de relativitat

L'autor hi justifica la necessitat d'ampliar la teoria de la relativitat especia

Un breu resum del desenvolupament de la teoria de la relativitat

Els trets essencials per a comprendre la teoria de la relativita

La mecànica de Newton i la seva influència en la formació de la física moderna

La primera traducció al català d'un article d'Einstei

Towards a Stable Numerical Evolution of Strongly Gravitating Systems in General Relativity: The Conformal Treatments

We study the stability of three-dimensional numerical evolutions of the Einstein equations, comparing the standard ADM formulation to variations on a family of formulations that separate out the conformal and traceless parts of the system. We develop an implementation of the conformal-traceless (CT) approach that has improved stability properties in evolving weak and strong gravitational fields, and for both vacuum and spacetimes with active coupling to matter sources. Cases studied include weak and strong gravitational wave packets, black holes, boson stars and neutron stars. We show under what conditions the CT approach gives better results in 3D numerical evolutions compared to the ADM formulation. In particular, we show that our implementation of the CT approach gives more long term stable evolutions than ADM in all the cases studied, but is less accurate in the short term for the range of resolutions used in our 3D simulations.Comment: 17 pages, 15 figures. Small changes in the text, and a change in the list of authors. One new reference adde