Shear Viscosity at Infinite Coupling: A Field Theory Calculation.

@article{Romatschke2021ShearVA,
  title={Shear Viscosity at Infinite Coupling: A Field Theory Calculation.},
  author={Paul Romatschke},
  journal={Physical review letters},
  year={2021},
  volume={127 11},
  pages={
          111603
        }
}
  • P. Romatschke
  • Published 13 April 2021
  • Physics
  • Physical review letters
I derive an exact integral expression for the ratio of shear viscosity over entropy density η/s for the massless (critical) O(N) model at large N with quartic interactions. The calculation is set up and performed entirely from the field theory side using a nonperturbative resummation scheme that captures all contributions to leading order in large N. In 2+1d, η/s is evaluated numerically at all values of the coupling. For infinite coupling, I find (η/s)≃0.42(1)×N. I show that this strong… 

Figures from this paper

On the Gravitational Wave to Matter Coupling of Superfluid Fermi Gases Near Unitarity
It is well known that gravitational waves distort equilibrium matter globally, mak-ing them amenable to detection with laser interferometers. Less well known is the fact that gravitational waves
Interacting CFTs for all couplings: Thermal versus Entanglement Entropy at Large $N$
: In this paper, I calculate the large N limit of marginal O ( N ) models in arbitrary odd dimensions d . This results in a new class of pure conformal field theories (CFTs) with non-polynomial
Dissipative processes at the acoustic horizon
Maria Luisa Chiofalo,1, 2 Dario Grasso,2, 1 Massimo Mannarelli,3 and Silvia Trabucco3, 4 Dipartimento di Fisica, Università di Pisa, Polo Fibonacci, Largo B. Pontecorvo 3, 56127 Pisa, Italy INFN,
Real-Time Dynamics At Large N
  • S. Lawrence
  • Physics
    Proceedings of The 38th International Symposium on Lattice Field Theory — PoS(LATTICE2021)
  • 2022
The large-N limit of O (N)-symmetric bosonic field theories, or U (N)-symmetric fermionic field theories, is amenable to a saddle point approximation. As a result, there is a family of closely

References

SHOWING 1-10 OF 72 REFERENCES
JHEP 02
  • 061
  • 2004
Phys
  • Rev. Lett. 122, 231603 (2019), [Erratum: Phys.Rev.Lett. 123, 209901
  • 2019
Finite-Temperature Conformal Field Theory Results for All Couplings: O(N) Model in 2+1 Dimensions.
TLDR
The massless O(N) model in 2+1 dimensions is revisited, and it is found that the entropy density monotonically decreases from the Stefan-Boltzmann limit at λ=0 to exactly 4/5 of the Stefan's limit atλ=∞.
Transseries for causal diffusive systems
Abstract The large proper-time behaviour of expanding boost-invariant fluids has provided many crucial insights into quark-gluon plasma dynamics. Here we formulate and explore the late-time
Three-dimensional Yukawa models and CFTs at strong and weak couplings
The massless three dimensional Gross-Neveu-Yukawa (GNY) and Nambu--Jona-Lasinio--Yukawa (NJLY) models at finite temperatures are analyzed within the mean field framework considering all coupling
Thermal free energy of large Nf QED in 2+1 dimensions from weak to strong coupling
In 2+1 dimensions, QED becomes exactly solvable for all values of the fermion charge $e$ in the limit of many fermions $N_f\gg 1$. We present results for the free energy density at finite temperature
Bayesian estimation of the specific shear and bulk viscosity of quark–gluon plasma
Ultrarelativistic collisions of heavy atomic nuclei produce an extremely hot and dense phase of matter, known as quark–gluon plasma (QGP), which behaves like a near-perfect fluid with the smallest
Analytic transport from weak to strong coupling in the O(N) model
In this work, a second-order transport coefficient (the curvature-matter coupling $\kappa$) is calculated exactly for the 3+1d O(N) model at large N for any coupling value. Since the theory is
Strong coupling universality at large N for pure CFT thermodynamics in 2+1 dimensions
A bstractPure CFTs have vanishing β-function at any value of the coupling. One example of a pure CFT is the O(N) Wess-Zumino model in 2+1 dimensions in the large N limit. This model can be
...
...