Magnetorotational instability in dense electron-positron-ion plasmas.

Area of Science:

• Plasma Physics
• Astrophysics
• Quantum Mechanics

Background:

• Magnetorotational instability (MRI) is crucial for angular momentum transport in astrophysical systems.
• Degenerate quantum plasmas, found in white dwarfs and neutron stars, exhibit complex behaviors.
• Spin magnetization effects in quantum plasmas are not fully understood.

Purpose of the Study:

• To analyze MRI in a multi-component quantum plasma including spin magnetization.
• To investigate the role of electron and positron number densities on MRI.
• To apply findings to astrophysical scenarios like white dwarfs and neutron stars.

Main Methods:

• Developed a multi-component quantum fluid model for electron-positron-ion (e-p-i) plasma.
• Derived general and local dispersion relations for MRI using MHD approximations.
• Numerically analyzed the reduced dispersion relation.

Main Results:

• Spin magnetization and particle number densities critically influence MRI dynamics.
• Increased electron number density and spin magnetization enhance MRI growth rates.
• This enhancement can lead to system instability and core collapse in massive stars.

Conclusions:

• Spin magnetization is a key factor in quantum plasma instability.
• The study provides insights into the core collapse mechanisms of massive stars.
• Findings are relevant for understanding extreme astrophysical environments.