Théorie

The aim of this thesis is the study of the quantum to classical transition
with a particular interest to quantum to classical gravity.
Of fundamental importance are the imprints left from quantum phenomenon
in the observed signal, such as CMB anisotropies and gravitational waves.

Quantum gravity is a hard task to tackle head-on.
Electromagnetism however is a case in which such a transition is well grounded this is the reason why,
as a starting point, we will consider the well known case of the electromagnetic field.

Study of the Quantum to classical transition (Directeur de these E.
Huguet APC UMR 7164, Univ. Paris Cité, co-encadrant J. Quéva, SPE UMR
6134, Univ. de Corse)
 
Quantum gravity is a hard task to tackle head-on.

RESEARCH THEME: Using the AdS/CFT correspondence to study phases of gauge theories at strong coupling, at finite temperature and density. A related problem is to understand the physics of cold nuclear matter in neutron stars.
 
RESEARCH GROUP in the Laboratory :  APC, Theory
 

RESEARCH THEME: Using the AdS/CFT correspondence to study de Sitter space and Inflation driven at strong coupling.
 
 
RESEARCH GROUP in the Laboratory : APC, Theory
 

The discovery of astrophysical neutrino signal by IceCube neutrino telescope has extended the energy frontier of astronomy into Peta-electronvolt energy range. The nature of astronomical sources operating powerful particle accelerators and producing the highest energy neutrinos is currently uncertain. A breakthrough toward understanding of the nature of these sources can be achieved via detection of the gamma-ray counterpart of the astrophysical neutrino signal. Gamma-ray signal at 100 TeV is now detectable by the HAWC, Tibet and LHAASO telescopes.

Magnetic fields that are relic of epochs right after the Big Bang can still reside in the low density regions of the Large Scale Structure, between galaxies and galaxy clusters. Detection of these fields and measurement of their properties might provide a valuable “window” on physical processes that have operated in the Early Universe a fraction of a second after the Big Bang. Such measurement is possible with the methods of gamma-ray and radio astronomies, using new observational facilities: gamma-ray Cherenkov Telescope Array (CTA) and radio Square Kilometer Array (SKA).

Astronomical observations through the new 100 TeV gamma-ray observational window by HAWC, Tibet  and LHAASO air shower arrays, and, in the near future, by the Cherenkov Telescope Array CTA open a range of completely new possibilities for the study of highest energy galactic cosmic ray sources. These sources, dubbed "PeVatrons" (yet to be identified) produce particles with energies in excess of Peta-electronVolt, three orders of magnitude higher than those attained in the most powerful human-made accelerator LHC.