In recent years several anomalies have been observed in decays of B-mesons. We give first a brief overview on the experimental situation. It is well know that these anomalies can be explained by adding leptoquarks or extra vector-bosons to the SM particle content.
Pedro Cunha defended his PhD thesis with title "Shadows and gravitational lensing of Black Holes interacting with fundamental fields" on September 9th 2019, at IST-Lisbon. The panel, composed by Prof. Volker Perlick, Frederic Vincent, José Natário, Carlos Herdeiro (advisor) and José Lemos (president) unanimously attributed the highest classification of Approved with Distinction and Honour to an outstanding piece of work. Congratulations Pedro!
In a paper published in Physical Review Letters, Gr@v researchers Pedro Cunha and Eugen Radu (in collaboration with Carlos Herdeiro from IST-Lisbon) provide a new insight on how spin could mask non-GR features in astrophysical black holes.
In this talk I describe a new class of superradiant instabilities in which ultralight scalar fields extract rotational energy from neutron stars. The instability arises from the mixing of scalar and photon modes in the magnetic field of the neutron star which extract energy from the rotating magnetosphere.
An extended scalar sector often emerges in models motivated by the electroweak hierarchy problem. In particular, a SM triplet is interesting because its decay is very constrained at the renormalizable level. Therefore, effective operators with a low cutoff make the triplet components decay promptly.
I'll discuss the role of the Higgs boson as a probe of the hidden sector. The latter is of particular importance in cosmology as it may host dark matter and the inflaton. Due to its scalar nature, the Higgs boson provides a unique handle on properties of such Standard Model--singlet states.
Gr@v warmly congratulates the Event Horizon Telescope collaboration for the first direct image of a black hole. This discovery has had a worldwide impact, including news coverage in Portugal with the contribution of Gr@v and former Gr@v members.
Axions can play very important roles in cosmology. They are interesting candidates for dark matter, dark energy, inflation but also, in the case of the QCD axion, a natural solution to the strong CP problem.
Our group coordinated the "Numerical Relativity and High Energy Physics" IRSES network (2012-2015). Here is a list of the global network meetings organized:
