3rd QGG Intensive Lectures: Spinfoam path integrals for Quantum Gravity
 Date
 July 26 (Wed) at 10:00  July 28 (Fri) at 19:00, 2023 (JST)
 Speaker

 Etera Livine (Research Director CNRS, Ecole Normale Supérieure de Lyon, France)
 Language
 English
 Host
 Puttarak Jaiakson
At the crossroads of several approaches to quantum gravity, Spinfoams propose a discrete path integral for quantum general relativity built from topological field theory. With the spectrum of geometric operators directly read from the representation theory of the local symmetry group, they can be interpreted as a quantized version of Regge calculus and can be understood as implementing the dynamics of quantum states geometry in loop quantum gravity. I will explain the basics of the formalism, the motivations, the mathematical framework and the main tools. In three spacetime dimensions, the spinfoam quantization of 3d gravity is given by the TuraevViro topological invariant, which is intimately related to the quantization of ChernSimons theory. I will explain in particular how the spinfoam amplitudes solve the Wheelerde Witt equation, implement the invariance under 3d diffeomorphisms (despite being formulated in a discretized spacetime) and lead to a quasilocal version of holography. In four spacetime dimensions, general relativity can be formulated as an almosttopological theory and I will explain how the existing spinfoam models introduce a sea of topological defects to recreate the gravitational degrees of freedom from a topological path integral. Finally, I will show how spinfoams are naturally defined in terms of group field theory, which are generalized tensor models, and the prospects that this opens. I will conclude with the main challenges and open lines of research of the field.
Program:
July 26
10:00  10:15 Registration and reception
10:15  11:45 Lecture 1
11:45  13:30 Lunch & coffee break
13:30  15:00 Lecture 2
15:00  16:00 Coffee break
16:00  17:00 Lecture 3
17:10  18:30 Short talk session
July 27
10:00  11:45 Lecture 4
11:45  13:30 Lunch & coffee break
13:30  15:00 Lecture 5
15:00  16:00 Coffee break
16:00  17:00 Lecture 6
17:30  20:00 Banquet
July 28
10:00  11:45 Lecture 7
11:45  13:30 Lunch & coffee break
13:30  15:00 Lecture 8
15:00  16:00 Coffee break
16:00  17:30 Lecture 9 & Closing
This is a closed event for scientists. Nonscientists are not allowed to attend. All scientists, including those outside RIKEN, are welcome to attend, please register using the registration form.