Atelier API "Ondes gravitationnelles et objets compacts"

Session

Projets financés

14 nov. 2022, 11:30

salle du château (Observatoire de Paris - site de Meudon)

10. Equation of state representation for neutron star oscillations

Gaël Servignat (LUTH)

14/11/2022 11:30

The choice of an equation of state is crucial in stellar structure. The most common choice is polytropes as they are good approximations for zero-temperature Fermi gas of electrons or nuclear matter. However, when going to more in-depth description of neutron stars, nuclear equations of state are needed to describe the interactions between baryons at very high densities. Those equations of...

11. Analytical representations of unified and modern equations of state

Lami Suleiman (Laboratoire Univers et Théories)

14/11/2022 12:00

Equations of state of dense matter play a key role in neutron star modelling. Well constructed equations of state must be constrained by nuclear physics experiments, and multi-messenger observations. But they must also be designed with the same nuclear model for the high density, and the low density part of the star. Yet, non-unified equations of state can be abundantly found in the...

13. Modelling the flares of Sagittarius A* observed by GRAVITY

Nicolas Aimar (LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. de Paris, Sorbonne Paris Cité, 5 place Jules Janssen, 92195 Meudon, France)

15/11/2022 10:00

For the past two decades, flares (i.e. outbursts of radiation) have been observed from the centre of the Milky Way where a massive compact object of 4.2 millions solar masses resides at only 8.3 kpc. This makes this object called Sgr A* the closest supermassive black hole candidate to Earth and an unique laboratory for relativistic astrophysics. Recent observations have shown that the source...

12. Gravitational waves emitted by the orbit of a massive object around a Boson Star

Samy Aoulad Lafkih (Observatoire de Paris)

15/11/2022 10:30

The future mission LISA will observe gravitational waves in a frequency range going from 10-4 to 10-1 Hz through three satellites orbiting in a heliocentric orbit. It is expected that this mission will detect the orbit of solar mass star orbiting around the compact object at the center of the Milky Way, Sagittarius A*. Depending on the orbit and the star’s mass, the gravitational waves emitted...

9. QFT methods for GW phyiscs

Stavros Mougiakakos (IPhT,CEA-Saclay)

16/11/2022 10:00

Recent years have seen a renewed interest in analytical treatments of the two body problem in gravity. This is mainly due to the recent detections of gravitational waves from binary coalescences. Lately, many tools originating from particle physics and QFT have been utilized for the analytic solution of the two-body problem in gravity such as EFT methods and modern methods for Scattering...

7. Towards multi-messenger observations of accreting binary black holes

Raphaël Mignon-Risse (CNES/APC)

16/11/2022 10:30

The many recent detections of gravitational waves (GWs) of binary black hole (BBHs) mergers have opened the way for future multimessenger campaigns. One expected result, not achieved yet, is the co-detection of electromagnetic (EM) radiation from a BBH merger system together with its GW inspiral emission, detectable for stellar-mass BHs with LIGO/Virgo, intermediate-mass BHs (and stellar-mass...