February 21, 2022
Spinning black holes are weird (well, all black holes are weird but those that spin are the worse!). They have a funny thing called ergoregion where orbiting particles can have negative energy. Penrose was the first to realize that this … Continue reading
May 6, 2020
A black-hole binary starts its life as two single black holes, and finish it as a single black hole. In between there’s all the complicated dynamics predicted by General Relativity: many orbits, dissipation of energy via gravitational waves, spins that … Continue reading
November 15, 2018
As you can imagine, I’m kind of obsessed with black hole binaries. So easy (let’s face it, a black hole is easy! Just mass and spin), but at the same time so terribly complicated… Happy to present our attempt to … Continue reading
November 14, 2018
Latest in the series of our spin-precession papers, here we found a thing that was worthy of a new name: wide nutation (we had wide precession before, but this is better). These are black-hole binary configurations where the angle between any … Continue reading
June 13, 2018
This is a massive review born out of the European COST Action CA16104 Gravitational waves, black holes and fundamental physics (GWverse). We summarize the status of the field of gravitational-wave astronomy and lie down a roadmap for the immediate future. Leor … Continue reading
December 16, 2016
Equal-mass binaries correspond to a discontinuous limit in the spin precession equations. A new constant of motion pops up, which can be exploited to study the dynamics. This is a really neat calculation done with Jakub, a Cambridge undergraduate student. Also, … Continue reading
February 22, 2016
Here we present 1+1 numerical-relativity simulation of stellar collapse in scalar-tensor theories, where gravity is mediated by the usual metric coupled to an additional scalar field. Bottom line: you can test General Relativity with supernovae explosions! Davide Gerosa, Ulrich Sperhake, Christian D. … Continue reading
May 27, 2015
What happens if you throw a scalar field into General Relativity? And if you throw more than one? Here is a paper on the phenomenology of neutron stars in theories with more than one scalar field coupled to gravity. Michael … Continue reading
January 28, 2015
A massive review on testing gravity, which came out of a nice meeting we had at University of Mississippi in January 2014. See the numbers. Emanuele Berti, et al. (53 authors incl. Davide Gerosa).Classical and Quantum Gravity 32 (2015) 24, 243001.arXiv:1501.07274 [gr-qc].