Back to agendaABSTRACT
Speakers: ICREA Research Professors Roberto Emparan and Mark Gieles, both from the Institut de Ciències del Cosmos (ICCUB)
When: 14th of September, 18:00 h
Where: Zoom
Abstracts:
Roberto Emparan
‘Love, echoes, and shadows: Tell-tale signs of a true black hole’
Black holes have been unambiguously proven to exist – or have they? Can we tell them apart from possible compact, dark impostors? Measurements of their so-called Love numbers, the presence of echoes in the gravitational wave signals, or details of their shadows in images, among other probes, might reveal whether we are actually observing the astonishing objects predicted by Einstein’s theory – or something else entirely’.
Mark Gieles
‘Black holes in star clusters as gravitational wave sources’
More than a billion years ago, two black holes spiralled in and collided, sending gravitational waves into the Universe at the speed of light. These were eventually detected on Earth in September 2015 by the laster interferometer gravitational-wave observatory (LIGO). This was the discovery of gravitational waves and confirmed a century-old prediction by Einstein’s theory of general theory and opened a new window on our Universe. Apart from its theoretical importance and technological accomplishment, the detection raised numerous astrophysical questions. Most importantly: how do these binary black holes form? Since the discovery, an additional 50 gravitational wave signals of colliding compact objects have been detected, mostly consisting of binary black holes and several involving neutron stars. We are now in the position to compare predictions of models of binary black hole formation to gravitational wave data and in this talk I will attempt to provide an overview of the current state of affairs. I will focus in particular on the model in which binary black holes form in gravitational interactions in dense stellar clusters.
The ICREA colloquia are a great way to learn about remote fields of research from our best experts. We usually have two speakers, who offer their opinions on the same subject from very different angles. They are open to all ICREAs and their guests.
