Thermal dynamics on the lattice with exponentially improved accuracy

Abstract

We present a novel simulation prescription for thermal quantum fields on a lattice that operates directly in imaginary frequency space. By distinguishing initial conditions from quantum dynamics it provides access to correlation functions also outside of the conventional Matsubara frequencies ${\omega }_n=2\pi nT$. In particular it resolves their frequency dependence between $\omega =0$ and ${\omega }_1=2\pi T$, where the thermal physics $\omega \sim T$ of e.g.~transport phenomena is dominantly encoded. Real-time spectral functions are related to these correlators via an integral transform with rational kernel, so their unfolding is exponentially improved compared to Euclidean simulations. We demonstrate this improvement within a $0+1$-dimensional scalar field theory and show that spectral features inaccessible in standard Euclidean simulations are quantitatively captured.

5 pages, 4 figures

References in corpus (13)

• Many-Body Physics with Ultracold Gases
• A calculation of the bulk viscosity in SU(3) gluodynamics
• Universal Quantum Viscosity in a Unitary Fermi Gas
• Exploring an ultracold Fermi-Fermi mixture: Interspecies Feshbach resonances and scattering properties of 6Li and 40K
• Charmonium properties in hot quenched lattice QCD
• Viscosity and scale invariance in the unitary Fermi gas
• Lattice simulations of real-time quantum fields
• Thermal dilepton rates and electrical conductivity of the QGP from the lattice
• In-Medium Spectral Functions of Vector- and Axial-Vector Mesons from the Functional Renormalization Group
• Towards quantitative precision in the chiral crossover: masses and fluctuation scales
• Functional renormalization group analysis of the soft mode at the QCD critical point
• Casimir interaction among heavy fermions in the BCS-BEC crossover
• Mobile impurity in a Fermi sea from the functional renormalization group analytically continued to real time

Cited by in corpus (6)

• Finite temperature spectral functions in the O(N)-model
• Large-N kinetic theory for highly occupied systems
• Bayesian analysis of quark spectral properties from the Dyson-Schwinger equation
• Towards QCD-assisted hydrodynamics for heavy-ion collision phenomenology
• Finite temperature gluon spectral functions from $N_f=2+1+1$ lattice QCD
• $Z_N$ symmetry in $SU(N)$ gauge theories