APC colloquium

APC Colloquium - LIGO and gravitational wave astronomy: ten years after the first detection

Ten years ago LIGO made the first direct detection of gravitational waves, emitted by the merger of two black holes about 1.3 billion years ago. Now, over 300 gravitational wave events have been observed by the LIGO-Virgo-KAGRA collaborations. Earlier this year, gravitational waves were detected from a black hole merger very similar to that first event in 2015, but this time with three times higher signal-to-noise ratio. This was thanks to the improvements in sensitivity that have been achieved in LIGO and Virgo in the past decade.

APC colloquium : The modeling of stellar explosions : How to connect the central engine to multi-messenger observations

The gravitational collapse of massive stars can lead to extreme stellar explosions when both fast rotation and strong magnetic fields are present during the onset of the supernova. This scenario is particularly important when it comes to exceptional sources such as hypernovae and long gamma-ray bursts, whose very high energy release can only be explained by progenitors with the most extreme physical conditions.

DESI shakes up the dark Universe

The Dark Energy Spectroscopic Instrument (DESI) is building the largest 3D map of our universe to measure its expansion history over the past 11 billion years, and, thereby, study dark energy. With the analysis of Baryon Acoustic Oscillations from its three-year (DR2) data set, DESI confirms the tantalizing hint of time-varying dark energy of the first-year studies. In this seminar, I will give an overview of the DESI experiment and present the most recent results on dark energy and neutrino masses using DESI data.

Hunting for millisecond pulsars at the heart of the Milky Way

Millisecond pulsars are magnetised, rapidly rotating neutron stars known to produce a pulsed emission at multiple frequencies, from radio to at least GeV energies. Stellar evolution models predict a large number of millisecond pulsars in the inner region of our Galaxy. However, their true contribution to the diffuse gamma-ray sky, and in particular to the Fermi GeV excess (which is also interpreted as an evidence for dark matter at the Galactic center), remains elusive.

(Cancelled) APC Colloquium : Solar Neutrinos: Is There a Future?

Studies of solar neutrinos have been tremendously important, revealing the nature of the Sun’s power source and that its neutrino flux is strongly affected by flavor mixing.  Nowadays, one gets the impression that this field is over.  However, this is not due to a lack of interesting questions; it is due to a lack of experimental progress.  I show how this can be solved, opening opportunities for discoveries in particle physics and astrophysics, simultaneously.
APC colloquium