Abstract: Usual Chern-Simons densities are defined only in odd dimensions. This is because they result from the one-dimension descent from the Chern-Pontryagin densities, and rely on the fact that the latter are total-divergence.
Abstract: Sun-like oscillations have been discovered in five hundred main sequence and sub-giant stars and in more than twelve thousand red giant stars in the solar neighbourhood. In this talk, I will argue how this network of natural detectors could be used to probe fundamental physics, including dark matter and gravitational waves. Moreover, these star detectors can complement the experimental research done on Earth. Moreover, this observational network of stars could be used to make other type of gravity tests, as unlike experimental detectors, it should be possible to follow the progression of gravitational waves throughout space. The continuous observation and monitoring of the oscillation spectra of the stars around us, within a sphere of up to one thousand parsecs, could help on the discovery of gravitational waves originating in our Galaxy or even elsewhere in the Universe.
The Essay "How fast can a black hole rotate?", by C. Herdeiro and E. Radu, was selected for an "Honorable Mention" in the Gravity Research Foundation 2015 Awards for Essays on Gravitation. It is the second consecutive year an essay from our group gets this distinction. The first prize was awarded to the Nobel Laureate Gerard 't Hooft, for the essay "Local Conformal Symmetry: the Missing Symmetry Component for Space and Time".
Abstract: It is well known that electromagnetic and gravitational waves scatter as well as get converted to one another by a charged black hole. We demonstrate that the electromagnetic and gravitational scattering and conversion cross s
Abstract: I will discuss the relevance of the spins of massive black holes as probes of the coevolution of these objects with their host galaxies, as well as for the dynamics of binary systems and accretion disks, and for gravitational-wave emission. I will also present a semi-analytical model for the cosmological evolution of the spins of the massive black-hole population, and show that comparison of this model to existing spin measurements from relativistic iron lines allows one to put constraints on competing accretion scenarios. I will also comment on the prospects to test this model using future gravitational-wave space-based detectors.
Our group coordinated the "Numerical Relativity and High Energy Physics" IRSES network (2012-2015). Here is a list of the global network meetings organized:
