Την Πέμπτη 23 Ιανουαρίου στις 15:00 στην αίθουσα σεμιναρίων του Σπουδαστηρίου Θεωρητικής Φυσικής (4ος όροφος), ο Matthieu Vilatte (University of Mons) θα δώσει μια τρίωρη εισαγωγική διάλεξη σε Φυσική Carrollian.
Θα υπάρχει ταυτόχρονη διαδικτυακή μετάδοση μέσω Zoom:
https://authgr.zoom.us/j/95325719397?pwd=YZj1Cx47sC33x8tlQ4LYWpYGjOZvmC.1
Meeting ID: 953 2571 9397
Passcode: 661090
Ακολουθεί ο τίτλος, η περίληψη και η βιβλιογραφία της διάλεξης:
Τίτλος: Asymptotically flat gravity and the emergence of Carrollian physics
Περίληψη: In this lecture we will study gravity in spacetimes that go back to Minkowski at infinity i.e. asymptotically flat spacetimes. This framework allows to study the gravitationnal field infinitely far away from an isolated source. Detailing the simple example of Minkoswski itself will reveal the existence of three types of infinities: timelike, spacelike and null. The last one being the locus where gravitationnal radiation can be captured, we will spend some time detailing its rigourous construction using the procedure of conformal compactification à la Penrose. Along the way we will discover that symmetries, namely (conformal) Carrollian symmetries, are at work at null infinity. Then, going in the so-called Bondi coordinates, we shall show the relation between (conformal) Carroll symmetries and the symmetries near infinity of asymptotically flat spacetimes, the BMS group. If time allows, we will finally explain how one can use these coordinates to prove the existence of gravitationnal waves in the non-linear regime of general relativity.
Βιβλιογραφία:
“The seminal papers”
– A. Ashtekar, Geometry and physics at null infinity, 1409.1800 [gr-qc]
– H. Bondi et al’, Gravitational waves in general relativity. 7. Waves from axisymmetric isolated systems, Proc.Roy.Soc.Lond.A 269 (1962) 21-52
– R.K. Sachs, Gravitational waves in general relativity. 8. Waves in asymptotically flat space-times, Proc.Roy.Soc.Lond.A 270 (1962) 103-126
– R. Penrose, Conformal treatment of infinity, Gen.Rel.Grav. 43 (2011) 901-922 (reprint), originally from 1962
“Modern approaches”
– R. Ruzziconi, Asymptotic symmetries and the gauge fixing approach to the BMS group, PoS Modave2019 (2020) 003
– A Fiorucci, Leaky covariant phase spaces and application to Lambda-BMS symmetry, PhD Thesis, Chapter 2.
