Research Projects

University of Aveiro
Supervisors: Carlos Herdeiro, Eugen Radu

Dark matter remains a central mystery of modern-day science. The elusiveness of dark matter candidates in colliders suggests we further search for its true nature where it was first unveiled - in astrophysics via its gravitational effects. In particular, the new golden age in strong gravity - with the gravitational wave era and remarkable new electromagnetic observations of compact objects - is providing intriguing hints on fuzzy dark matter. Such phenomenological studies start from constructing appropriate compact objects where such fuzzy dark matter plays a key role, both new types of black holes and horizonless compact objects. This thesis aims to go beyond the simplest fuzzy dark matter models based on Abelian fields. A dark sector, like the visible one, may contain non-Abelian fields. The central goal of this thesis is the impact of such fields on the phenomenology of compact objects, connecting them to gravitational wave and electromagnetic observations.

University of Aveiro
Supervisors: Carlos Herdeiro, Eugen Radu

This project is divided into five interconnected parts, studying : 1) the theory of deviations from the Kerr paradigm, and, in particular, the construction of alternative models, both in modified gravity and in General Relativity in the presence of dark matter candidates, as ultralight bosons. 2) effects of light bending by BNs and their shadow, in these alternative models, making contact with the Event Horizon Telescope (EHT) observations. 3) gravitational waves emitted in different dynamic scenarios involving these alternative models, making contact with data from the LIGO-Virgo Scientific Collaboration. 4) other astrophysical phenomenological aspects of alternative models, namely orbits of stars. 5) on the theoretical front, concrete scenarios beyond the standard model of particle physics, where ultra-light dark matter models have theoretical support, considering the constraints of particle accelerators, namely the Large Hadron Collider (LHC).

University of São Paulo
Supervisor: Betti Hartmann

The construction of exact axisymmetric solutions of the Einstein-Maxwell equations possessing the prescribed physical properties means the obtaining of solutions in which different parameters would correspond to different relativistic multipole moments determining the structure of space-time. Associated with this, there are various solution-generating techniques based on integrable models that can be employed to obtain particular families of solutions from any suitable “seed” solution, one of them, known as Sbigatullin’s method, is applied. Sibgatullin’s method is fully revised and its parameters in the N-soliton solution are conected with Einstein-Maxwell multipoles moments.

University of São Paulo
Supervisor: Domingos Alves

We are a team of independent scientists from several Brazilian research institutions, highly motivated to contribute to the control of the coronavirus outbreak that took place in Brazil, based on the real-time monitoring of data provided by official sources on the spread of the virus in the country. Besides, we will use scientifically based analysis tools to help managers, authorities, and the population in general, to face this actual war against COVID-19. On the portal ciis.fmrp.usp.br/covid19, I was responsible for monitoring Brazil, updating the monitoring of daily cases and daily deaths with moving average, data projection for the next ten days based on exponential modeling of all capitals and states (and Brazil). I also wrote some opinion articles based on scientific evidence.

Federal University of Espírito Santo
Supervisor: Gabriel Luchini

The Aharanov-Bohm effect was discussed in detail : from the introduction of fundamental concepts about electromagnetism as a gauge theory, the repercussions of this symmetry in quantum mechanics and its construction based on the Stokes theorem for the introduction of the geometric phase. In addition to the usual, more conceptual discussions about the effect, the problem of quantum electron scattering in a region with a confined magnetic field is made.

Federal University of Espírito Santo
Supervisor: Gabriel Luchini

The so-called Heisenberg model describes magnetic systems very well in different situations of interest. In the continuous limit,with the imposition of a bond on the norm of this field, the dynamics of the spin field of the Heisenberg continuous model is equivalent to the static solutions of the two-dimensional non-linear sigma model. A study was carried out on the existence, stability and behaviour of solitons in different geometries, that is, in spaces with cylindrical symmetry, so that there is the ”coupling” of the spin with the geometry making the anisotropic model in a certain sense. By rewriting the equations of motion as Bogomol’nyi equations and including an axial symmetry ansatz for the spin field, it was possible to understand how to simplify the equations of motion and obtain analytical solutions for surfaces with axial symmetry.