Séminaire / Seminar GReCO |
| « Shedding light on fundamental physics with Planck » |
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Silvia Galli |
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The universe as pictured by the recent data release of the Planck satellite is remarkably “simple”, well described by a LCDM model (apart from few hints of anomalies). However, the nature of some of the basic components of this model, i.e. of dark matter and dark energy, is still unknown and represents one of the major puzzles of modern cosmology and modern physics; it might even be the hint that currently known physics is not enough to describe our universe.
In this talk, I will propose two ways to investigate these problems with the Planck data. First, I will show how the CMB is an extremely powerful tool to constrain fundamental characteristics of dark matter particles, as it strongly constrains dark matter annihilation. Annihilation is a standard prediction of many popular current dark matter models, and it is one of the candidates for the interpretation of the anomalies detected in cosmic and gamma ray data by several experiments such as Pamela, AMS02 and Fermi. I will review the general ideas behind searches of dark matter annihilation with the CMB and present the most recent developments in the field. Second (time permitting), I will show how the detection of hundreds of new galaxy clusters through the Sunyaev-Zel'dovich effect by Planck and other ongoing experiments is a potentially powerful new probe of fundamental physics. In particular, the x-ray and SZ observations of these objects can be used to test the value of fundamental constants, i.e. to test the validity of currently known physics, at redshifts z< 1. I will show that current data can constrain the value of the fine structure constant at the level of 0.8%, comparable to CMB constraints |
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lundi 7 octobre 2013 - 11:00 Salle des séminaires François Arago Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |