In this talk I will firstly give a brief introduction on what bosonic stars are and why should we be interested in studying them. Then, I will present a study of the non-linear dynamics of both boson(scalar) and Proca(vector) stars, through numerical relativity techniques. I will depict three different physical scenarios. At first I will consider the spherically symmetric Einstein-(complex)Proca system and show how, starting with Proca field distributions that obey the Hamiltonian, momentum and Gaussian constraints, the self-gravity of the system induces the formation of compact objects, which, for appropriate initial conditions, asymptotically approach stationary soliton-like solutions known as Proca stars. Then I will further explore the dynamical properties of these solitonic objects by showing both head-on collisions and orbital mergers of equal mass spherically symmetric Proca stars. The last part of the talk will be about the formation of spinning bosonic stars, both scalar and vector case. This is the first fully non-linear numerical evolutions of the Einstein-(complex, massive) Klein-Gordon and Einstein--(complex, massive) Proca systems, to assess the formation and stability of spinning bosonic stars. In the scalar case the formation is transient; a non-axisymmetric instability always develops ejecting all the angular momentum from the scalar star. In the Proca case, by contrast, no instability is observed and the evolutions are compatible with the formation of a spinning Proca star. Our analysis suggests bosonic stars have different stability properties in the scalar/vector case, which we tentatively relate to their toroidal/spheroidal morphology.

# Formation and mergers of bosonic stars

## Next Seminar

## The first portait of a black hole & beyond

## Next Journal Club

## Discussion of the paper "On Continued Gravitational Contraction" by J. R. Oppenheimer and H. Snyder

## Black Hole Workshops

Next workshop:

XIII Black Holes Workshop, Algarve,

21-22 December 2020

Previous workshops in the series:

I Black Holes Workshop, Porto, 2008

II Black Holes Workshop, Lisbon, 2009

III Black Holes Workshop, Minho, 2010

IV Black Holes Workshop, Aveiro, 2011

V Black Holes Workshop, Lisbon, 2012

VI Black Holes Workshop, Minho 2013

VII Black Holes Workshop, Aveiro 2014

VIII Black Holes Workshop, Lisbon 2015

IX Black Holes Workshop, Minho 2016

X Black Holes Workshop, Aveiro 2017

XI Black Holes Workshop, Lisbon, 2018

XII Black Holes Workshop, Minho, 2019

## Numerical data

## FunFiCO Network

Our group coordinates the Marie Curie RISE FunFiCO network (Dec 2017- Dec 2021)

More info here

## GWVerse COST

## StronGrHEP Network

Our group is part of the RISE StronGrHEP network (2016-2019)

Meetings:

Paris, 12-13 May 2016

Azores, 3-8 July 2017

Osaka, 4-8 September 2017

## NRHEP Network Meetings

Our group coordinated the "Numerical Relativity and High Energy Physics" IRSES network (2012-2015). Here is a list of the global network meetings organized:

First Meeting:

9-13 July 2012, Aveiro, Portugal

Second Meeting:

11-14 March 2013, Lisbon, Portugal

Third Meeting:

6-10 January 2014, Mississippi, USA

Fourth Meeting:

7-10 July 2015, Rome, Italy

Fifth Meeting:

28 Sep-2 Oct 2015, Belém, Brazil

## Ph.D. and Post-doctoral opportunities

Contact us If you are interested in pursuing graduate studies/research in our group.