Séminaire

The European Low Frequency Survey: observing the radio sky to understand the beginning of the Universe

Nowadays the leading contender to understand the initial conditions of the Big Bang is inflation, which predicts the existence of a primordial background of gravitational waves that must have left its imprint in the CMB polarization: the so-called ​ B-modes. The main difficulty in measuring the ​ B-modes comes not just from its sheer faintness but from the fact that many other objects in the universe also emit polarized microwaves.

Reconstruction of neutrino events in the MicroBooNE detector 

MicroBooNE is a Liquid Argon Time Projection Chamber (LArTPC) neutrino experiment on the Booster Neutrino Beamline at the Fermi National Accelerator Laboratory, with an 85-tonne active mass.
One of MicroBooNE’s primary physics goals is to investigate the excess of electron neutrino events seen by MiniBooNE in the [200-600] MeV range.
MicroBooNE will constrain the intrinsic electron neutrino component of the beam by measuring the muon neutrino spectrum.

Vainshtein screening for slowly rotating stars 

We study the Vainshtein mechanism in the context of slowly rotating stars in scalar-tensor theories.
While the Vainshtein screening is well established for spherically symmetric spacetimes, we introduce a slow rotation of the source and examine its validity in the axi-symmetric case.
We solve for the frame-dragging function accounting for the slow rotation and show that the deviations from the general relativity (GR) solution are screened in the weak-field approximation, meaning the solution for the frame-dragging function is the same as GR to leading order.

The power of probe combination : cosmology with LSS and CMB data

Through weak lensing and galaxy clustering measurements, the next generation of large-scale surveys (Euclid, LSST, ...) will provide unprecedented observations and constraints on the late Universe, and thus shed light on dark matter and dark energy. On the other hand, high-quality CMB observations (current and planned) can -- and already do -- put tight constraints on the early Universe and its content.

Pages

S'abonner à RSS - Séminaire