Key words : Statistical physics and statistical field theory (O. Coquand; P.M. Déjardin); Phase transitions (O. Coquand); Fluid Mechanics (X. Chesneau, M. David); Thermics (X. Chesneau, M. David); Spectroscopy (A. Ceausu-Velcescu; P.M. Déjardin); Physical Chemistry (A. Ceausu-Velcescu); Dequantization (W. Briec)
The "Physics of Complex Systems" theme is concerned with the modeling of certain properties and behaviors of various phases of condensed matter. It covers several areas, including :
- Gas-phase molecular spectroscopy;
- The flow of complex fluids in the presence of thermal effects;
- The temperature-dependent dielectric properties of polar fluids;
- The temperature-dependent magnetic properties of ferrofluids;
- The rheology of complex liquids and granular materials, etc.
This theme is essentially theoretical.
To achieve these objectives, it draws on certain areas of theoretical physics (quantum mechanics, statistical physics, electromagnetism, fluid mechanics, field theory), advanced mathematical tools and numerical techniques such as numerical simulation of solutions to partial differential equations, integro-differential equations, etc.
The aim of this research theme is to develop efficient methods for studying "complex" systems, i.e. those with characteristics that prevent them from being described using standard tools (large number of particles, multiple phase transitions, non-equilibrium thermodynamics, superposition of numerous vibrational modes, etc.). Such systems can be found, for example, in atomic or molecular systems, but also in the objects we encounter in our daily lives : water, mud, toothpaste, air-conditionning systems, etc.
The description of such systems within this axis is achieved through the appication of a wide variety of techniques : use of advanced numerical computation procedures, statistical calculations, phase transition models, analytical resolution of partial differential equations using advanced computational tools. The complementarity of these different approaches enables a global description of a wide variety of complex systems, and highlights the analogies and bridges existing between the different description tools.
Mise à jour le 3 juillet 2025