Certain scalar-tensor theories remain viable despite stringent observational constraints from the Solar System due to a Z_2 symmetry that keeps the scalar field dormant in the weak-field regime. However, extreme-gravity environments can trigger a phase transition that promotes the spontaneous growth of the scalar field around compact objects like black holes and neutron stars.
Gravitational-wave population studies have become a common approach to learn about the astrophysical distribution of merging stellar-mass binary black holes. The goal is to map the source properties (e.g., masses and spins) of events observed by ground-based interferometers, which have been filtered through detection biases, to the true parameter distributions as a whole across the population.
Topological solitons play an important role in many areas of Physics. In some cases they constitute the {\em normal modes} of field theories in the strong coupling regime. There is a class of topological solitons that are special. They are solutions of first order differential equations (self-dual eqs.) that also solve the second order Euler-Lagrange equations.
We will first show how Finsler spacetimes naturally appear as a tool to solve the time-dependent Zermelo problem in a manifold M, or more generally, the problem of finding the shortest trajectory in time when the velocity is prescribed at any direction and any instant of time, namely, the velocity is a function of the direction and the time.
The 12th Iberian Gravitational Waves Meeting will take place at the University of Minho, in Braga, from 6-8 June 2022, co-organized by our group. More information in the event's webpage.
Jorge Delgado successfully defended his Ph.D. thesis, entitled "Spinning Black holes with scalar hair and horizonless compact objects within and beyond General Relativity" on March 24 2022. The Ph.D. committee included José Pedro (President, UA), Betti Hartmann (UCL), Yasha Shnir (JINR), Luis Crispino (UFPA), Lara Sousa (IA, UP) and Carlos Herdeiro (UA, advisor). The thesis was co-advised by Eugen Radu. Congratulations Jorge!
Gr@v made an appearance in Portuguese National TV, in the show UAU, "Science without limits", co-produced by RTP and the University of Aveiro. Episode 14 was devoted to space, and our group talked about gravitational waves and the possibility they can give us information on dark matter, based on this article.
A call for a 1 year postdoctoral grant in Strong Gravity or High Energy Physics, to integrate the Gravitational Geometry and Dynamics Group within the CIDMA research Unit, is open from 5 to 20 April 2021. See attached document for details: call in Portuguese and English.
Starting from March 2022, C. Herdeiro was appointed member of the editorial board (associate editor) of the European Physical Journal C (EPJC), for the section "Theoretical Physics III: Quantum Field Theory and Gravity - Fundamental and Formal Aspects". EPJC is a leading international journal on this research topic with over 2M downloads in 2021 and an impact factor of 4.590 (2020). See UA coverage here.
Our group coordinated the "Numerical Relativity and High Energy Physics" IRSES network (2012-2015). Here is a list of the global network meetings organized:
