English

Entanglement Viscosity: from Unitarity to Irreversibility in Accelerated Frames

High Energy Physics - Theory 2026-01-06 v1 High Energy Physics - Phenomenology Nuclear Theory

Abstract

We demonstrate that the unitarity of quantum field theory, through the positivity of spectral functions, underlies thermodynamic irreversibility for a subsystem separated by a horizon, in direct analogy with the irreversibility of renormalization-group flows. To this end, we explicitly find the shear and bulk viscosities -- the entanglement viscosities -- for thermal radiation in Rindler space using the universal spectral representation. A direct consequence of the obtained general formulas is the relationship between the acceleration-induced shear viscosity in flat space and the conformal quantum anomaly in curved space, pointing to a possible novel probe of the conformal anomaly in systems with extreme acceleration. Moreover, for conformal field theories, we explicitly show that globally entanglement viscosity saturates the Kovtun-Son-Starinets bound.

Keywords

Cite

@article{arxiv.2601.02083,
  title  = {Entanglement Viscosity: from Unitarity to Irreversibility in Accelerated Frames},
  author = {G. Yu. Prokhorov},
  journal= {arXiv preprint arXiv:2601.02083},
  year   = {2026}
}

Comments

6 pages

R2 v1 2026-07-01T08:50:49.479Z