Name: Conceptual Issues in Fundamental Physics
Start: 2017-06-09T08:00:00+02:00
End: 2017-06-13T18:00:00+02:00
Location: LPSC Grenoble (June 9th) & LAPTh Annecy (June 13th)

Conceptual Issues in Fundamental Physics

de vendredi 9 juin 2017 (08:00) à mardi 13 juin 2017 (18:00)

lundi 5 juin 2017
mardi 6 juin 2017
mercredi 7 juin 2017
jeudi 8 juin 2017
vendredi 9 juin 2017

09:45 Café
Café
09:45 - 10:30
10:30 Introduction - Luca Fabbri (-)
Introduction
- Luca Fabbri (-)
10:30 - 10:35
10:35 No Time No Problem - Francesca Vidotto (IMAPP Nijmegen)
No Time No Problem
- Francesca Vidotto (IMAPP Nijmegen)
10:35 - 12:35
Exactly half of a century ago Wheeler and de Witt wrote the iconic first equation of quantum gravity. Puzzlingly, the equation does not feature any time variable. Where is time gone? How can we describe the evolution of physical systems in absence of a preferred time variable? How can time emerge in the passage from the quantum to the classical world? I will review the problem, the strategies adopted to overcome it and some insights from ongoing research in quantum gravity.
14:00 Do Virtual Particles Really Exist? - Marco Guagnelli (INFN Pavia)
Do Virtual Particles Really Exist?
- Marco Guagnelli (INFN Pavia)
14:00 - 16:00
When physicists tried to unify Quantum Mechanics with Relativity, it soon became clear that the resulting theory could not conceivably be a single particle one. Creation and destruction of particles had to be taken into account. The theory we end up with is a Relativistic Quantum Field Theory: particles are just quanta of the respective fields. The outstanding success of Feynman's Path Integral formalism brought into some kind of "physical reality" the so called "virtual particles". Virtual particles are not observable asymptotic states, but can exist as long as they don't violate Heisenberg uncertainty principle. Their existence is used, didactically, to explain a lot of phenomena; for example, the running of the electron charge, or coupling constant, with energy, via the screening obtained by vacuum polarization of the cloud of e+ e- virtual couples that surround the "true" electron. I'd like to discuss what happens to this kind of reasoning when a QFT is treated in a non-perturbative way.
samedi 10 juin 2017
dimanche 11 juin 2017