QMat Student Seminars
The QMat Student Seminars are courses organized by QMat students at the Faculty of Physics and Engineering, in partnership with the Tutoring Division of the ARIANE, the GeQS group and the Strasbourg Students Physical Letters.
They are intended to foster a better understanding of theoretical aspects of quantum sciences among physics students. When not stated otherwise, all seminars are held at the Institut de Physique in Strasbourg, and the proceedings are published in the 2SPL.
For more information regarding the QMat Student Seminars, please contact Simon BEAUDOIN.
2024-2025 Second semester
20th March (10h-12h): Symmetries and representations in high-energy physics
Target audience: L3-M2
Room 130 (SAP Master classroom), Building 26, IPHC, Cronenbourg Campus
The theory of groups and their representations leads to numerous applications, notably in high-energy physics. Lie groups and their associated Lie algebras allow us to represent continuous symmetries. Representations of the Poincaré group are used to classify particles according to their spin, defining concepts such as fermions and bosons, but also associating different types of tensors and spinors to different particles. The "calculus of representations" is also the basis of the quark model, used to predict the existence of hadrons and to compute their quantum numbers. In the end, the seminar aims to answer the question "What is a particle?"
27th March (10h-12h): Elements of classical field theory II (Gauge theories)
Target audience: M1-M2
Room 103
After the discussion of Noether’s theorem in the first seminar (15/10/2024), we introduce gauge theories as a very general procedure allowing us to extend the perimeter of some field theories. Several examples are discussed, and gauge theories are shown to be the current best mathematical description of fundamental interactions. The relation of classical field theory with relativistic quantum mechanics and general relativity is discussed, although no previous knowledge of these domains is assumed. Attendance at the first seminar is not required to understand the notions discussed here, since general results on field theories and Noether's theorem will be recalled at the beginning (it helps, though).
1st April (9h-10h30): Structure formation in cosmology
Target audience: L3-M2
Room 130 (SAP Master classroom), Building 26, IPHC, Cronenbourg Campus
The matter of our universe is concentrated into galaxies and galaxy clusters. At even larger scales, those galaxy clusters are distributed on a complex network of filaments, walls and voids called the cosmic web. How could all these structures emerge from a nearly uniform density ? The aim of this seminar is to provide some answers to this question. We will first present a classical model based on newtonian gravity, and then give elements of the more complete theory of gauge invariant cosmological perturbations. In the final part of the seminar, we will discuss some observational tensions related to the large scale structure of the universe, and that may motivate new physics beyond the standard model of cosmology.
2024-2025 First Semester
27th September (16h-17h30): Tensor calculus for physicists
Target audience: L3-M1
Fresnel Amphitheater
Tensors are quite general mathematical objects, used in almost all areas of physics, from continuum mechanics to general relativity and quantum physics. Beginning with a reminder of some useful concepts of linear algebra, this seminar introduces the notion of tensor, discusses its relation with metrics, covariance and contravariance in Euclidean and Minkowski spaces, and eventually presents tensor products in the context of quantum mechanics.
15th October (14h-16h): Elements of classical field theory I (Formalism and symmetries)
Target audience: M1-M2
Fresnel Amphitheater
Classical field theory is the branch of mathematical physics dealing with non-quantized fields as representations of physical objects. The first historical motivation for using fields was of course Maxwell’s theory of electromagnetism,which revealed how powerful this kind of formalism might be. This seminar first introduces the mathematical notion of field, and how it can be connected to physics through Lagrangians. The consequences of field symmetries are investigated, namely Noether’s theorem on conserved currents and charges.
2nd December (10h-12h): Construction of the quantum state space
Target audience: L3-M2
Room 103
The first postulate of Quantum Mechanics states that a system’s state is completely characterized by some vector, which is an element of an abstract space called the state space. The features of this space may vary considerably from one system to another, and even for simple systems, the physical interpretation of the state vectors is not always straightforward. This seminar aims at elaborating a rigorous, step-by-step, construction of the state space associated to real space variables, first for systems with 1 degree of freedom (one particle evolving in one dimension), and then for 3D and many-body systems. Generalized kets (non-normalizable states) are tackled from the mathematical and physical point of views. The state space associated to spin variables is introduced in a second part, allowing us to discuss the notions of quantum entanglement and indistinguishability.