Abhay Ashtekar
Institute for Gravitation & the Cosmos, Pennsylvania State University (University Park, Pennsylvania, Etats-Unis d'Amérique)
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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| « Quantum Gravity in the Sky? » |
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Abhay Ashtekar |
| I will discuss a two way bridge between a ‘fundamental’ description of the very early universe based on Loop Quantum Cosmology (LQC), and the spectacular observations we have from the PLANCK satellite. Contrary to a wide-spread belief, the pre-inflationary dynamics in the quantum gravity regime can have observational consequences. In partic- ular, proposals within LQC naturally lead to power suppression at large angular scales, both for T-T and E-E correlations. In turn, we find a larger value for the optical depth t than predicted by standard inflation. Finally, the tension with the value of the lensing amplitude AL –that has led some cosmologists to suggest that there is a “crisis”– is alleviated. The talk is aimed at a broad audience and in particular will not assume familiarity with quantum gravity. |
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vendredi 7 février 2020 - 11:00 Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |