Quantum field theories out of thermal equilibrium

Horsley, R.; Schoenmaker, Wim

doi:10.1016/0550-3213(87)90170-2

Cited by 69 publications

(63 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…0, sound waves can propagate to asymptotically large distances. As this limit coincides with the infrared limit in which the transport coefficients are calculated [6][7][8], these two limits do not, in general, commute: In the low viscosity limit the viscosity needs to be renormalized by a contribution due to sound waves traveling to asymptotically large distances. Assuming the maximum wave number of sound waves k max $ 1=, when the ''bare viscosity'' !…”

Section: Introductionmentioning

confidence: 91%

Viscosity of an ideal relativistic quantum fluid: A perturbative study

Torrieri

2012

Phys. Rev. D

View full text Add to dashboard Cite

We show that a quantized ideal fluid will generally exhibit a small but non-zero viscosity due to the backreaction of quantum soundwaves on the background. We use an effective field theory expansion to estimate this viscosity to first order in perturbation theory. We discuss our results, and whether this estimate can be used to obtain a more model-independent estimate of the "quantum bound" on the viscosity of physical systemsComment: Accepted for publication, Phys.Rev.D. Discussion slightly clarified and extended, references added, error in calculation fixed. COnclusions unchange

show abstract

Section: Introductionmentioning

confidence: 91%

Viscosity of an ideal relativistic quantum fluid: A perturbative study

Torrieri

2012

Phys. Rev. D

View full text Add to dashboard Cite

show abstract

“…In other more rigorous derivations of the Kubo formulas [25,26,27], where they do not use energy-momentum conservation in the correlators, the expression of the bulk viscosity involves the operator…”

Section: Kubo's Formulae For Transport Coefficientsmentioning

confidence: 99%

Transport coefficients and resonances for a meson gas in chiral perturbation theory

2009

View full text Add to dashboard Cite

Abstract. We present recent results on a systematic method to calculate transport coefficients for a meson gas (in particular, we analyze a pion gas) at low temperatures in the context of Chiral Perturbation Theory (ChPT). Our method is based on the study of Feynman diagrams taking into account collisions in the plasma by means of the non-zero particle width. This implies a modification of the standard ChPT power counting scheme. We discuss the importance of unitarity, which allows for an accurate high energy description of scattering amplitudes, generating dynamically the ρ(770) and f0(600) mesons. Our results are compatible with analyses of kinetic theory, both in the non-relativistic very low-T regime and near the transition. We show the behavior with temperature of the electrical and thermal conductivities as well as of the shear and bulk viscosities. We obtain that bulk viscosity is negligible against shear viscosity, except near the chiral phase transition where the conformal anomaly might induce larger bulk effects. Different asymptotic limits for transport coefficients, large-Nc scaling and some applications to heavy-ion collisions are studied. PACS

show abstract

“…In contrast, in scalar field theory [21] as well as for photons interacting with massive particles of a thermal fluid [22], it was shown that the ratio ζ/η is uniquely determined by…”

Section: Introductionmentioning

confidence: 99%

Ratio of bulk to shear viscosity in a quasigluon plasma: From weak to strong coupling

2012

View full text Add to dashboard Cite

The ratio of bulk to shear viscosity is expected to exhibit a different behaviour in weakly and in strongly coupled systems. This can be expressed by its dependence on the squared sound velocity. In the high temperature QCD plasma at small running coupling, the viscosity ratio is uniquely determined by a quadratic dependence on the conformality measure, whereas in certain strongly coupled and nearly conformal theories this dependence is linear. Employing an effective kinetic theory of quasiparticle excitations with medium-modified dispersion relation, we analyze the ratio of bulk to shear viscosity of the gluon plasma. We show that in this approach, depending on the temperature, the viscosity ratio exhibits either of these dependencies found by means of weak coupling perturbative or strong coupling holographic techniques. The turning point between the two different dependencies is located around the maximum in the scaled interaction measure.

show abstract

Quantum field theories out of thermal equilibrium

Cited by 69 publications

References 19 publications

Viscosity of an ideal relativistic quantum fluid: A perturbative study

Viscosity of an ideal relativistic quantum fluid: A perturbative study

Transport coefficients and resonances for a meson gas in chiral perturbation theory

Ratio of bulk to shear viscosity in a quasigluon plasma: From weak to strong coupling

Contact Info

Product

Resources

About