Isotropization of a Rotating and Longitudinally Expanding ϕ⁴ Scalar System.

Area of Science:

• Cosmology
• Theoretical Physics
• Computational Physics

Background:

• Scalar fields are fundamental in many cosmological models.
• Understanding the dynamics of expanding systems is crucial for cosmology.
• Non-isotropic and rotating initial conditions present complex theoretical challenges.

Purpose of the Study:

• To numerically investigate the evolution of an expanding system of scalar fields.
• To analyze the isotropization of pressures and the decay of angular momentum.
• To compare the characteristic time scales of these processes.

Main Methods:

• Numerical simulations of scalar field evolution.
• Calculation of the energy-momentum tensor.
• Calculation of the angular momentum vector.

Main Results:

• The system exhibits non-isotropic expansion.
• The energy-momentum tensor and angular momentum vector were computed.
• A significant decay of initial angular momentum was observed.
• The decay of angular momentum is faster than the isotropization of pressure anisotropy.

Conclusions:

• Initial angular momentum decays considerably faster than pressure anisotropy.
• Numerical simulations provide insights into complex scalar field dynamics.
• The findings contribute to understanding the evolution of early universe models.