Dynamics of scalar and vector boson stars
Speaker
Carlos Herdeiro and Nico Sanchis-Gual
Event date
Venue
GAP room
Event type
Strong Gravity News & Events
COST Action "Gravitational Waves, black holes and fundamental physics"
The COST Action 16104 on "Gravitational Waves, black holes and fundamental physics" has been approved within the EU Framework Program Horizon 2020. The action is led by Prof. Vitor Cardoso and our group participated in the network of proposers. C. Herdeiro is a member of the management committee.
Interview to Porto Canal
For the second time C. Herdeiro was the guest interviewee of Porto Canal's "Mentes que Brilham". Watch and listen to the conversation (from minute 18 onwards) (Watch and listen to the first interview) with interviewer Cláudia Fonseca about black holes and some of the research work made at Gr@v in this area.
From Infinitely Large to Infinitely Small
Gr@v member António P. Morais gave a talk at Escola Secundária José Régio in Vila do Conde with title "Do Infinitamente Grande ao Infinitamente Pequeno - uma jornada pelas interações fundamentais na natureza". António was an invited speaker to participate in a sequence of seminars entitled "A Biblioteca convida...", and presented to 11th and 12th grade Science and Technology students the four fundamental interactions in nature and how have they shaped our Universe.
Critical behavior of a domain wall collapse
Speaker
Taishi Ikeda (Nagoya U.)
Event date
Venue
GAP room
Event type
Abstract: Gravitational collapse is the one of the most important phenomena of gravity. About 20 years ago, Choptuik discovered a critical collapse in the massless scalar system. After this discovery, many author have shown that the critical behavior appears in the many systems, and it contains to the rich phenomena.
In particular, Okawa et al showed the massive scalar system, which has the typical length scale, has a non trivial phase diagram with respect to the critical collapse. In this study, we consider the spherically symmetric domain wall collapse. Because this system also has the typical length scale in the action, it is expected that this system also has the non trivial phase diagram. In order to analyze non-trivial phase diagram of this system, we study the gravitational collapse of this system around threshold of the BH formation. In this talk, as a first step of this study, I will show that the type II critical collapse appears in some parameter region in this system.
The first "Alberto" Prize
The first "Alberto" prize, awarded to a young researcher in the area of General Relativity by the SPRG was presented in the IX Black Holes Workshop to Jorge Rocha, currently at the University of Barcelona. The award is a hologram of an image of Albert Einstein, which was produced by Pedro Pombo and Emanuel Santos, at the U. Aveiro.
5th UTQuest Workshop
Gr@v member Carlos Herdeiro was one of the invited speakers of the 5th UTQuest workshop, with the theme "Hidden Sector Physics and Cosmophysics", that took place at the Yukawa Insitute for Theoretical Physics, Kyoto University, Kyoto, Japan.
The spacetime around neutron stars and astrophysical observables
Speaker
Georgios Pappas (GRIT - CENTRA - IST)
Event date
Venue
GAP room
Event type
Abstract: Compact objects in general and neutron stars (NSs) in particular open a window to some of the most extreme physics we can find in nature. On the one hand in the interior of NSs we can find matter in very extreme densities, exceeding nuclear densities and anything we can probe in the laboratory, while on the other hand NSs are related to the strongest gravitational fields next only to those found in black holes. Therefore studying NSs gives us access to both supranuclear densities and strong gravity and can be used to get information and test our theories of matter (equation of state) and gravity. The properties of the structure of NSs are encoded on the spacetime around them and by studying the astrophysical processes that take place around NSs we can map that spacetime.Here we will talk about the properties of NS structure and how they are related to the properties of the spacetime around them. We will also talk about the relation of these properties to astrophysical observables. Finally we will extend our discussion to the case of scalar-tensor theory of gravity.
A journey into a black hole
Gr@v's Ph.D. student (in collaboration with IST-Lisbon) Pedro Cunha produced a short movie illustrating a voyage into a black hole, and in particular the lensing effects visualized by an observer undergoing such journey. The journalist Catarina Lázaro (voice) and Gr@v researcher C. Herdeiro (scientific advising) collaborated in the movie, which will have a premiere on December 3rd 2016 at "Observatório Geofísico e Astronómico da Universidade de Coimbra".
Distorted black holes in Physical Review Letters
Can a black hole have a cube-like horizon (with round edges) or any of the other shapes above? The article "Static Einstein-Maxwell black holes with no spatial isometries in AdS space", by Gr@v member C. Herdeiro and E. Radu, published in Physical Review Letters, shows that it can.
Anti-de-Sitter (AdS) space gives yet another example of how special "standard" black holes are.