Shear viscosity of a relativistic scalar field from functional renormalization

2025/12/21 by Tim Stoetzel, Stefan Floerchinger, Stoetzel, Tim +1
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #Functional renormalization group #High Energy Physics - Theory (hep-th) #High-Energy Particle Collisions Research #Renormalization #Renormalization group #Resummation #Scalar (mathematics) #Scalar field #Shear viscosity #Volume viscosity

paper · open access · doi:10.48550/arxiv.2512.18740

published in arXiv (Cornell University) (Cornell University)

openalex publication_date 2025/12/21 · openalex created_date 2025/12/24 · openalex updated_date 2026/07/28

Abstract

Renormalization group flow equations of the fluid dynamical shear viscosity transport coefficient of a relativistic real scalar field are derived. The flowing effective action contains branch cut contributions to the self energy and interaction vertex in the symmetric phase. We demonstrate how the flow equation method can systematically extend the perturbative resummation schemes. We show that our truncation is in that sense a minimal scheme in which a reliable viscosity coefficient is obtained.

Citations

• Energy-momentum response to metric perturbations in the fluid dynamic regime
• Analytic structure of stress-energy response functions and new Kubo formulae
• Relativistic Fluid Dynamics In and Out of Equilibrium -- Ten Years of\n Progress in Theory and Numerical Simulations of Nuclear Collisions
• Exact evolution equation for the effective potential
• The renormalization group and the ε expansion
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