David Kosower vient d’obtenir l’ERC Advanced Grant Ampl2Einstein.
Ce projet sera consacré au développement de nouveaux calculs perturbatifs pour l’étude de l´émission d´ondes gravitationnelles lors de la fusion de trous noirs ou d'étoiles à neutrons. Ces calculs de précision sont une étape cruciale afin de pouvoir extraire des observations des informations sur la structure de ces astres.
L' ambition du projet “Ampl2Einstein” est de repousser les limites de la théorie quantique des champs et de développer le lien entre théories de Yang-Mills et théories de gravitation. Son objet est d´utiliser les avancées des dernières années dans l´étude des amplitudes de diffusion pour les appliquer à l'étude des signaux gravitationnels dorénavant accessibles aux observations astronomiques. Toutes nos félicitations à David!
A virus spreads over the "contact network" whose nodes are individuals, and the link represents the possibility for the virus to spread between them. This contact network is therefore not necessarily equivalent to our social network and has a very complex structure. The study of this type of network is used today in epidemiology to understand how a virus spreads. Liberation released today an interview with Marc Barthelemy, director of research at the Institute of theoretical physics (CEA).
Collisions between heavy atomic nuclei at ultrarelativistic energies are carried out at particle colliders to produce the quark–gluon plasma, a state of matter where quarks and gluons are not confined into hadrons, and colour degrees of freedom are liberated. This state is thought to be produced as a transient phenomenon before it fragments into thousands of particles that reach the particle detectors. Despite two decades of investigations, one of the big open challenges is to obtain an experimental determination of the temperature reached in a heavy-ion collision, and a simultaneous determination of another thermodynamic quantity, such as the entropy density, that would give access to the number of degrees of freedom.
In a Letter published recently in Nature Physics, two physicists from IPhT, Jean-Yves Ollitrault and Giuliano Giacalone, in collaboration with Fernando Gardim, from Federal University of Alfenas (Brazil), in sabbatical at IPhT, and Matthew Luzum, from the University of São Paulo (Brazil), obtain such a determination. Using experimental data, they show that the matter created in lead–lead collisions at the Large Hadron Collider reaches a temperature of 2.6 trillion degrees, the hottest ever achieved in the laboratory. They determine the corresponding entropy density and the speed of sound, which is half the speed of light in this state of matter. Results inferred from experiment agree with first principles calculations and confirms that a deconfined phase of matter is indeed produced.
Un nouvel ouvrage co-écrit par Pierfrancesco Urbani, physicien à l’IPhT
2020-01-31 14:15:00
Un nouvel ouvrage co-écrit par Henri Orland, physicien à l'IPhT
2020-01-28 16:16:00
Black holes and the Weak Gravity Conjecture
2019-12-12 15:59:00
Black holes and the Weak Gravity Conjecture
2019-12-12 15:59:00
Machine Learning and the Physical Sciences
2019-12-11 14:17:00
2019-11-18 09:39:00
Philippe Brax (IPhT), representing UP Saclay in EuCAPT
2019-11-04 14:18:00
Quantum Field Theory : A book by François Gélis.
2019-07-25 00:00:00
