Transport coefficients for hard-sphere relativistic gas

Area of Science:

• Physics
• Statistical Mechanics
• Computational Physics

Background:

• Transport coefficients are vital for understanding gas behavior in theoretical and experimental physics.
• Existing research primarily focuses on classical systems, leaving a gap in understanding massive relativistic gases.
• Relativistic effects on transport properties remain under-explored in scientific literature.

Purpose of the Study:

• To numerically determine transport coefficients for a hard sphere relativistic gas.
• To evaluate the accuracy of Chapman-Enskog (CE) theory for relativistic systems across a range of temperatures.
• To identify the limitations of linear CE theory in extremely relativistic regimes.

Main Methods:

• Employing fully relativistic molecular dynamics simulations.
• Utilizing Helfand-Einstein expressions to calculate transport coefficients.
• Comparing simulation data with Chapman-Enskog theoretical predictions.

Main Results:

• Simulation data closely matches CE predictions at low temperatures.
• Deviations between simulation data and CE predictions increase with rising temperature.
• Thermal conductivity shows excellent agreement with CE theory across all tested temperatures.
• Observed deviations suggest limitations of linear CE theory in extremely relativistic scenarios.

Conclusions:

• Relativistic molecular dynamics simulations provide valuable insights into transport coefficients.
• Chapman-Enskog theory shows good accuracy at lower temperatures but deviates significantly at higher, extremely relativistic temperatures.
• The study highlights the need for refined theoretical models to accurately describe transport phenomena in massive relativistic gases.