Gr@v Ph.D. students Alexandre Pombo, João Oliveira and Jorge Delgado visited Belém, Brazil as members of the FunFiCO Marie Curie RISE project. Their visit coincided with the VII Amazonian Workshop on Gravity and analogue models, where they presented their work, and the Amazonian High Studies School in Theoretical Physics where they attended courses on Numerical Relativity and Gravitational Lensing.
Current and former Gr@v members met at the 22nd International Conference on General Relativity and Gravitation (GR22) in Valencia, Spain. Great talks and great discussions!
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.
The article Warm Little Inflaton becomes Cold Dark Matter, by Gr@v members João G. Rosa and Luís B. Ventura has been published in Physical Review Letters.
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.
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.
Gr@v member Valério Ribeiro was part of an international team of researchers studying thermonuclear eruptions in the Andromeda galaxy. The team published, in Nature magazine, the discovery of a super-nova remnant which is bigger than most supernova remnants. They found that the super-nova remnant was the consequence of yearly repeated eruptions over millions of years. Few of these systems are known in the galaxy due to the fact that we suffer from dust obscuration.
The reduced phase space quantization of a closed Friedmann Universe is described. Its matter content is constituted by a specific perfect fluid. It is shown that, for this particular model, specific boundary conditions can be related to the algebra of Dirac observables.
Professor Kunihito Uzawa from Kwansei Gakuin University, Japan, visited Gr@v in the last week of September 2018 and gave a seminar on "No-Go theorems for ekpyrosis from ten-dimensional supergravity". (In the photo with Eugen Radu.)