Group “Fundamental Interactions”
The quantum gravity team works on a major open question in fundamental physics: how to reconcile general relativity and quantum mechanics. Since gravity describes the dynamics of space-time, this amounts to studying the quantum behavior of time and space.
Loop quantum gravity (LQG) is a major approach aimed at answering this question. In this field, the CPT is at the very forefront, and the team works on the formal definition of the theory, its mathematical aspects, and its applications.
Among the formal developments, the group studies the properties of coherent semiclassical states, which describe quantum geometry, and develops a reformulation of the theory in terms of twistors, which should simplify its application.
The main applications are primordial cosmology and black hole physics. The objective of this research is to identify observable phenomena that could make it possible to test the theory. In the context of cosmology, LQG makes it possible to explore the region close to the initial singularity predicted by classical general relativity. The theory indicates that the current expansion phase of the universe was preceded by a phase of contraction.
LQG also allows the study of the high-curvature region inside black holes (the “Planck star”) and suggests that the central singularity is avoided thanks to quantum effects. The black hole thus becomes unstable: it can explode through a quantum tunneling process, similar to conventional nuclear decay. The team studies the signals produced in this way, which could correspond to observed phenomena such as very high-energy gamma rays or Fast Radio Bursts, possibly caused by explosions of primordial black holes. The quantum structure of space-time is also relevant for studying the thermal properties of black holes and the “information paradox”. The group is at the forefront of the analysis of these questions.
| BRUNO | Matteo | Post Ph.D. | Contact | |
| DIAZ | Juan-Manuel | Ph.D. | Contact | |
| DONA | Pietro | Research teacher | Contact | |
| KRAJEWSKI | Thomas | Research teacher | +33.4.91.26.95.53 | Contact |
| PEREZ | Alejandro | Research teacher Team leader « Quantum Gravity » | +33.4.91.26.97.98 | Contact |
| PIOVESAN | Pierre | Ph.D. | Contact | |
| ROVELLI | Carlo | Research teacher emeritus | +33.4.91.26.96.44 | Contact |
| SPEZIALE | Simone | Researcher Unit leader « Interactions fondamentales » | +33.4.91.26.95.47 | Contact |
| SREERAM | Gowrisankar | Ph.D. | Contact | |
| YAN | Ruijue | Ph.D. | Contact |
Casimir energy for two and three superconducting coupled cavities: numerical calculations
The European Physical Journal Plus, 2017, 132 (11), pp.478. (10.1140/epjp/i2017-11750-y)
The Second Law of Thermodynamics at the Microscopic Scale
Foundations of Physics, 2017, 47 (9), pp.1185-1190. (10.1007/s10701-017-0104-5)
The boundary is mixed
General Relativity and Gravitation, 2017, 49 (8), pp.100. (10.1007/s10714-017-2263-2)
Weighing the vacuum with the Archimedes experiment
12th Frascati Workshop on Multifrequency Behaviour of High Energy Cosmic Sources, Jun 2017, Palermo, Italy. pp.084, (10.22323/1.306.0084)
Michelangelo's Stone: an Argument against Platonism in Mathematics
European Journal for Philosophy of Science, 2017, 7 (2), pp.285-297. (10.1007/s13194-016-0159-8)
Loop gravity string
Physical Review D, 2017, 95 (10), pp.106002. (10.1103/PhysRevD.95.106002)
Quantum Geometry and Black Holes
A. Ashtekar; J. Pullin. Loop Quantum Gravity : The First 30 Years , 4, World Scientific, pp.241-279, 2017, 100 Years of General Relativity, 978-981-3209-92-3. (10.1142/9789813220003_0008)
A note on the Poisson bracket of 2d smeared fluxes in loop quantum gravity
Classical and Quantum Gravity, 2017, 34 (10), pp.107001. (10.1088/1361-6382/aa69b4)
Black Holes in Loop Quantum Gravity
Reports on Progress in Physics, 2017, 80 (12), pp.126901. (10.1088/1361-6633/aa7e14)
Sachs’ free data in real connection variables
Journal of High Energy Physics, 2017, 11, pp.205. (10.1007/JHEP11(2017)205)
