The significance of multi-ring images in the optical appearance of spherically symmetric compact objects is discussed. Such images are produced by an optically and geometrically thin accretion disk illuminating the object.
M. Zilhão was one of the invited speakers at the Grav24 conference, held at FAMAF, Universidad Nacional de Córdoba, Argentina, from April 8th to April 12th 2024. This edition celebrated the 65th birthdays of Oscar Reula, Osvaldo Moreschi, and Carlos Kozameh.
P. Cunha and C. Herdeiro were invited speakers at the online workshop on numerical and analytical relativity (NAR-2024), organized by the Department of Applied Sciences, Indian Institute of Information Technology Allahabad (IIITA) during 20 - 22 March 2024. The video recorded lectures can be seen here.
A call for two 12-month research grants in Strong Gravity for M.Sc. holders, within the scope of the project Gravitational waves, black holes, and fundamental physics, 2022.04560.PTDC, is open from April 5 to April 19 (2024). See attached documents for details or the Euraxess announcement here.
Numerical Relativity is a key tool for the study of strong-field gravity. I will present a new evolution code, based on the Kadath library. It relies on multidomain spectral methods for the space discretization, and explicit time integration schemes.
The Einstein-Hilbert action is the simplest possible generally covariant action for gravity. While Einstein's equations conform with all observational data, theoretical considerations suggest the possibility to add higher curvature correction terms to Einstein's theory.
Our group coordinated the "Numerical Relativity and High Energy Physics" IRSES network (2012-2015). Here is a list of the global network meetings organized:
