Microscale Dynamics and Non-Maxwellian Equilibria: Decoding Collisionless Processes in the Space Plasmas

Research Project, 2026 – 2028

Plasma is the most common state of matter in the visible Universe. In most plasma environments, such as in accretion disks, the intracluster medium, and the heliosphere, the negligible collisionality allows particle velocity distributions to deviate from the Maxwell-Boltzmann thermodynamic equilibrium. Nevertheless, non-Maxwellian equilibrium eVDFs can emerge. Recent developments in Lynden-Bell statistical mechanics and kinetic Vlasov theory of electrostatic turbulence suggest that such equilibria are universal features of collisionless plasmas. I am applying for a three-year project which aims to investigate the nature and universality of these equilibria in heliospheric plasma. The project will adopt an innovative, data-driven approach that integrates in situ spacecraft observations, theory, and numerical simulations. Using high-resolution spacecraft data, we will perform a statistical characterisation of non-Maxwellian equilibria in the heliosphere. Complementarily, kinetic Vlasov theory and numerical simulations will be employed to investigate how microscale turbulence and field-particle interactions influence the formation and stability of these equilibria. By combining observations, theory, and simulations, this project will advance our understanding of the statistical thermodynamics of collisionless, turbulent plasmas and provide new insight into the universal behaviour of plasmas across astrophysical environments.