Effects of Instabilities in Collisionless Astrophysical Plasmas: Dynamo, Magnetic Field Reconnection and Isotropization

• Grant number: 24/16327-3
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: July 01, 2025
• End date: February 29, 2028
• Field of knowledge: Physical Sciences and Mathematics - Physics - Physics of Fluids, Plasma Physics and Electrical Discharge
• Principal Investigator: Grzegorz Kowal
• Grantee: Gabriel Luiz Ferreira Santos
• Host Institution: Instituto Nacional de Pesquisas Espaciais (INPE). Ministério da Ciência, Tecnologia e Inovação (Brasil). São José dos Campos , SP, Brazil
• Associated research grant: 21/06502-4 - Interlink between turbulence, magnetic reconnection, and cosmic-ray production in non-relativistic and relativistic astrophysical plasmas, AP.JP2

Abstract

In this research, we seek to deepen our understanding of the dynamic processes governing magnetized plasmas in various astrophysical environments, with a particular focus on the weakly collisional regime. In such plasmas, where collisions are infrequent, pressure anisotropy can occur, leading to significant instabilities. These instabilities can modify magnetic fields and plasma dynamics, driving processes such as magnetic reconnection, turbulence generation, and altering the diffusion of cosmic rays, which are crucial for the evolution of astrophysical systems.The study will utilize the Chew-Goldberger-Low magnetohydrodynamic formalism (CGL-MHD). From an analytical perspective, the present proposal is dedicated to improving the CGL-MHD approximation by including additional terms that account for pressure isotropization. The research will also incorporate advanced numerical simulations using spectral methods, finite volume methods, and particle-in-cell (PIC) algorithms, which will play a comparative role with the theory. These simulations will track the trajectories of particles to understand how interactions within the plasma lead to the reduction of pressure anisotropy.Subsequently, the proposal envisions application in different astrophysical scenarios, including magnetic field amplification during the early Universe, magnetic reconnection in turbulent environments, and the diffusion of cosmic rays in weakly collisional and collisionless plasmas, comparing the CGL-MHD approach with traditional MHD models. The project, scheduled for completion in February 2028, aims to significantly advance our understanding of plasma behavior in cosmic environments, contributing valuable insights to the fields of plasma physics and astrophysics. (AU)