Otro
Shear viscosity from thermal fluctuations in relativistic conformal fluid dynamics
Registro en:
Journal of High Energy Physics. New York: Springer, n. 2, p. 25, 2012.
1126-6708
10.1007/JHEP02(2012)085
WOS:000301453400005
Autor
Peralta-Ramos, J.
Calzetta, E.
Resumen
Within the framework of relativistic fluctuating hydrodynamics we compute the contribution of thermal fluctuations to the effective infrared shear viscosity of a conformal fluid, focusing on quadratic (in fluctuations), second order (in velocity gradients) terms in the conservation equations. Our approach is based on the separation of hydrodynamic fields in soft and ultrasoft sectors, in which the effective shear viscosity arises due to the action of the soft modes on the evolution of the ultrasoft ones. We find that for a strongly coupled fluid with small shear viscosity-to-entropy ratio eta/s the contribution of thermal fluctuations to the effective shear viscosity is small but significant. Using realistic estimates for the strongly coupled quark-gluon plasma created in heavy ion collisions, we find that for eta/s close to the AdS/CFT lower bound 1/(4 pi) the correction is positive and at most amounts to 10% in the temperature range 200-300MeV, whereas for larger values eta/s similar to 2/(4 pi) the correction is negligible. For weakly coupled theories the correction is very small even for eta/s = 0.08 and can be neglected. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)