The “Fundamental Interactions” Group brings together the following teams:
It is accepted today that physics in all its complexity, ranging from subnuclear scales on the order of $10^{-20}$ m to cosmological scales on the order of $10^{26}$ m, is understood in terms of three fundamental interactions: gravitational, electroweak, and strong forces. Despite the enormous gap in scales, these forces are described in a coherent manner by similar theories based on the two conceptual revolutions of 20th-century physics: the theory of relativity and quantum mechanics. The models constructed utilize field theory, geometry, and group theory.
The mathematical study of these theories, and their generalizations, are explored within our group, and more specifically within the “Geometry, Physics, and Symmetries” team.
The “Particle Physics” team specializes in comparing models with experimental results at subnuclear scales, particularly large-scale numerical simulations of Lattice Quantum Chromodynamics, effective field theories, low-energy precision experiments, and dark matter research.
Over the last twenty-five years, cosmology has remarkably gathered observations that challenge previously accepted models. Our “Cosmology” team focuses on two main enigmas: the accelerated expansion of the universe, and the anomalies observed in the dynamics and the way matter clusters at cosmological scales.
The coherence mentioned above is, in fact, incomplete: despite the intense efforts of many physicists since the two major revolutions of the 20th century, there is still no quantum description of gravity. The “Quantum Gravity” team has taken up this challenge and is at the forefront of global research. Among its research themes are Big Bang physics and phenomenology at the center of black holes.
Particle Physics
In connection with particle physics experiments and the search for dark matter, we test the limits of the Standard Model and explore new models of fundamental physics that could explain some of its shortcomings.
Geometry, Physics, and Symmetries
Our activities concern the mathematical description of physical laws, particularly fundamental interactions. They bring to light new mathematical structures or may have immediate physical applications.
Cosmology
By studying the structure of space-time at the cosmic scale, we seek to understand enigmatic phenomena, such as the acceleration of the universe’s expansion (dark energy) or anomalies in the movement and distribution of matter in the universe (dark matter).
Quantum Gravity
Our team studies the quantum properties of gravity, i.e., the quantum aspects of time and space. It is a leader in the loop approach, applied to cosmology and black holes, to seek experimental confirmations.
