Phys.org November 7, 2024
Researchers in Germany derived a general theory of the viscosity of gases based on the relativistic Langevin equation and nonaffine linear response theory. The proposed relativistic theory was able to recover the viscosity of nonrelativistic classical gases, with all its key dependencies on mass, temperature, particle diameter, and Boltzmann constant, in the limit of Lorentz factor =1. It also unveiled the relativistic enhancement mechanism of viscosity. According to the researchers in the limit of ultra relativistic fluids, the theory provides an analytical formula which reproduces the cubic increase of viscosity with temperature in agreement with various estimates for hot dense matter and the quark-gluon-plasma-type fluid… read more. TECHNICAL ARTICLEÂ Â Â Full text