LUTh seminars

La solution homogène et isotrope des équations d’Einstein dite LambdaCDM, assortie de ses perturbations linéaires et d’ordres supérieurs, forme le socle de la cosmologie contemporaine permettant de comprendre, dans ses grandes lignes, l’évolution ...

Tidal Love numbers provide us a handle to test the nature of compact objects, as well as theories of gravity. There have been several clarifications recently, which makes our understanding of these Love numbers better. But further investigations h...

In general relativity, freely-falling objects follow geodesics of the background spacetime in which they live. In a sense, this feature is a mere rephrasing of Einstein’s equivalence principle. In 1968, Brandon Carter showed that the geodesic mot...

Lie algebras are an important class of algebras with deep applications to physics. We will give a brief overview of the mathematical definition. After this, we will discuss the current implementation in SageMath, including finite dimensional, affi...

In high-energy and multi-messenger astrophysics, much of the phenomenology relates to the dissipation of an energy reservoir into accelerated particles that then radiate in various channels (cosmic rays, electromagnetic signals, from radio to gamm...

The LIGO-Virgo-KAGRA (LVK) collaboration has published about 90 gravitational wave observation since the first detection in 2015, majority of which have been from binary black holes. With such a statistically significant number of events it is pos...

Compact stars have a crucial role to play in our understanding of ultra dense and isospin asymmetric matter. Born in the extremely bright explosion of a massive star at the last stage of its life, neutron stars can present masses as high as twice ...

In the era of the multi-messenger astronomy, ultra-high energy cosmic rays offer the unique opportunity to investigate the nature of astrophysical sources and of particle interactions in an energy range far beyond that covered by current particle ...

In this talk, will review the recent progresses that our team has made using Gaia DR3 data. It includes the detection of a significant (Keplerian) decrease for the rotation curve of our Galaxy, and the fact that most Milky Way dwarfs are newcomers...

In this talk, we will explore entangled relativity, a general theory of relativity that offers a more parsimonious approach compared to general relativity when integrated within a quantum field theory framework. Requiring only two universal dimens...

Accurate and efficient modeling of binary black holes (BBHs) is crucial for the detection of gravitational waves (GWs) emitted by them. Closed-form solutions to these systems when they are in the initial inspiral phase are highly sought after and ...

In this seminar, I will present what are paleo-detectors, how they work, and what they are useful for. I will show the base ideas for their employment in astroparticle physics, with specific cases for neutrino, dark matter, and cosmic ray physics....

High-cadence long-term monitoring of the transient sky suggests that most core-collapse supernovae are influenced at some level by interaction with circumstellar material (CSM). Although considered so far a feature in core-collapse supernovae, thi...

In this seminar, I will present recent results concerning the analysis of gamma-ray bursts (GRB) afterglows and on the formation of binary neutron stars (BNSs). I will show a new model of the very high energy emission of GRB afterglows from the sy...

Il y a près de 13 milliards d’années, notre univers est né, mais ce n’est que depuis le siècle dernier que la théorie du « Big Bang » a été élaborée pour expliquer sa naissance et son évolution. Cette théorie affirme que l’Univers était extrême...

Les trous noirs sont des astres tellement compacts que même la lumière ne peut leur échapper. Tout ce qui s’en approche trop est condamné a y être englouti. Si l’existence de ces objets est prédite depuis plus de 100 ans par la théorie de la re...

La fusion de deux étoiles à neutrons se produit lorsque les deux étoiles en orbite l’une autour de l’autre se rapprochent de plus en plus jusqu’à entrer en collision. Ce processus s’accompagne entre autres de l’émission d’ondes gravitationnelles e...

Cyg X-3 is a high-mass X-ray binary, and is the only system in the Milky Way consisting of a Wolf-Rayet star and a compact object. The nature of the compact object (neutron star / black hole) is still unclear. Despite numerous studies, Cyg X-3 re...

Since the discovery of neutron stars (NSs) as pulsating sources ∼50 years ago, pulsars have become the perfect laboratories to test the boundaries of theoretical physics, thanks to the extreme astrophysical environments they thrive in. Arguably th...

Since the launch of the Fermi/LAT gamma-ray telescope, several hundred radio-loud gamma-ray pulsars have been detected, many belonging to millisecond pulsars but some also to the young pulsar population (spin periods longer than 30 ms). Observ...