Venue: SALÓN MERIDIANO de la Facultad de Ciencias Astronómicas y Geofísicas de la Universidad Nacional de La Plata. Argentina.
PROGRAM:
10.00-11.00 Carlos Argüelles (IALP-CONICET)
Title: Elementary particle-based models for dark matter on galaxy scales
Abstract:
The problem of describing dark matter (DM) halos in terms of self-gravitating (fundamental) particles has gained considerable attention in the last years, given they may provide solutions to many of the unsuccessful predictions of the cold dark matter (CDM) paradigm arising below ~10 kpc scales. Such models are mainly comprised between (i) The case of ultra light bosons with masses in the range m~1-100x10^(-22) eV; and (ii) The case of keV fermions including for temperature as well as relativistic effects (i.e. the RAR model). The main consequence of incorporating the quantum (pressure) effects when dealing with either the case of bosons or fermions under self-gravity, is in the novel core-halo morphology of the density profiles. I will describe the underlying physical properties of the above theories, their astrophysical consequences to DM halos in galaxies and structure formation, as well as the tensions and success when contrasted with different observational data-sets.
11.00-11.30 Café
11.30-12.30 Gastón Giribet (Universidad de Buenos Aires FCEyN-UBA)
Title: Observational constraints on modified gravity theories from supermassive black hole shadows
Abstract:
In this talk, after a brief review of the recently obtained image of a supermassive black hole by the Event Horizon Telescope collaboration, I will talk about my work done in collaboration with the people from IAFE, in which, almost ten years ago, we already anticipated how the scrutiny of the shape of the shadow casted by a supermassive black hole could allow us to constrain deviations from general relativity. I will also discuss other observational bounds on modified gravity theories coming from other astrophysical phenomena, such as the Primakoff effect in stars.
12.30-14.30 Almuerzo
14.30-15.30 Gabriel Bengochea (IAFE)
Title: Current challenges in determining the Hubble constant
Abstract:
One of the current debates in cosmology faces the tension between, on the one hand, the value obtained for the Hubble constant (Ho) through
observations of the cosmic microwave background (CMB) and, on the other hand, the corresponding value determined by local observations,
such as inferred luminosity distances from the use of type Ia supernovae. Recently, the greatest discrepancy between these two
approaches was reported, placing the tension in 4.4 sigmas at the confidence level.
In this talk I will make a brief review of the debate and mention some observational aspects related to type Ia supernovae that could lead
(or not) to the reduction of the current tension between different determinations of Ho.
15.30-16.00 Café
16.00-17.00 Ezequiel Alvarez (ICAS)
Title: GW detectors to explore Quantum Gravity and Dark Matter: how far we are.
Abstract:
We have a new amazing working tool: the Gravitation Wave detectors. We pose the question of whether, in addition to their original main purpose of detecting GWs, there is more information that can be extracted form their data. In this talk we discuss in particular how far are we of having a hint on Quantum Gravity using their data, and if they could be used to detect Dark Matter lumps passing through them. As it could be expected, results are of course very negative; however I think that it is interesting to pose the discussion and explore if we can further develop ideas that could lead us to more interesting results.