Reconstructing QCD Spectral Functions with Gaussian Processes

Abstract

We reconstruct ghost and gluon spectral functions in 2+1 flavor QCD with Gaussian process regression. This framework allows us to largely suppress spurious oscillations and other common reconstruction artifacts by specifying generic magnitude and length scale parameters in the kernel function. The Euclidean propagator data are taken from lattice simulations with domain wall fermions at the physical point. For the infrared and ultraviolet extensions of the lattice propagators as well as the low-frequency asymptotics of the ghost spectral function, we utilize results from functional computations in Yang-Mills theory and QCD. This further reduces the systematic error significantly. Our numerical results are compared against a direct real-time functional computation of the ghost and an earlier reconstruction of the gluon in Yang-Mills theory. The systematic approach presented in this work offers a promising route towards unveiling real-time properties of QCD.

12 pages, 5 figures

References in corpus (21)

• Lattice gluodynamics computation of Landau-gauge Green's functions in the deep infrared
• Baryons as relativistic three-quark bound states
• Pinch Technique: Theory and Applications
• Three-point vertices in Landau-gauge Yang-Mills theory
• Exploratory study of three-point Green's functions in Landau-gauge Yang-Mills theory
• Nevanlinna Analytical Continuation
• Fully coupled functional equations for the quark sector of QCD
• The strong running coupling from the gauge sector of Domain Wall lattice QCD with physical quark masses
• Further Evidence For Zero Crossing On The Three Gluon Vertex
• Analytical Continuation of Matrix-Valued Functions: Carathéodory Formalism
• Does The Lattice Zero Momentum Gluon Propagator for Pure Gauge SU(3) Yang-Mills Theory Vanish in the Infinite Volume Limit?
• Ghost spectral function from the spectral Dyson-Schwinger equation
• Ghost dynamics in the soft gluon limit
• Infrared facets of the three-gluon vertex
• A test on analytic continuation of thermal imaginary-time data
• The analytic structure of the lattice Landau gauge gluon and ghost propagators
• Bayesian inference of non-positive spectral functions in quantum field theory
• Reconstructing confined particles with complex singularities
• Collective charge excitations and the metal-insulator transition in the square lattice Hubbard-Coulomb model
• Dispersion relations for unphysical particles
• Projected Regression Methods for Inverting Fredholm Integrals: Formalism and Application to Analytical Continuation

Cited by in corpus (28)

• Machine Learning in Nuclear Physics
• Progress on stochastic analytic continuation of quantum Monte Carlo data
• Exploring QCD matter in extreme conditions with Machine Learning
• Gauge Sector Dynamics in QCD
• The Present and Future of QCD
• Probing the energy-smeared R-ratio on the lattice
• Reconstructing spectral functions via automatic differentiation
• Electromagnetic Properties of Indium Isotopes Elucidate the Doubly Magic Character of ${}^{100}$Sn
• Non-perturbative strong coupling at timelike momenta
• On the quark spectral function in QCD
• The QCD moat regime and its real-time properties
• Yang-Mills glueball masses from spectral reconstruction
• Inverse problems, real-time dynamics and lattice simulations
• Bayesian inference of real-time dynamics from lattice QCD
• Neural network approach to reconstructing spectral functions and complex poles of confined particles
• Probing the singularities of the Landau-gauge gluon and ghost propagators with rational approximants
• Lattice QCD estimates of thermal photon production from the QGP
• Spectral Functions of Gauge Theories with Banks-Zaks Fixed Points
• The analytic structure of the Landau gauge quark propagator from Padé analysis
• The analytic structure of three-point functions from contour deformations
• Reconstructing lattice QCD spectral functions with stochastic pole expansion and Nevanlinna analytic continuation
• On the complex structure of Yang-Mills theory
• The Schwinger function, confinement and positivity violation in pure gauge QED
• Analytic continuation and physical content of the gluon propagator
• Spectral properties and observables in ultracold Fermi gases
• Spinning Pairs: Supporting ${}^3{P}_0$ Quark-Pair Creation from Landau Gauge Green's Functions
• Nevanlinna-Pick interpolation from uncertain data
• Mean-field theory for self-interacting relativistic Luttinger fermions