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 (72)

• A Method for Simulating Chiral Fermions on the Lattice
• Chiral Fermions from Lattice Boundaries
• The nonperturbative functional renormalization group and its applications
• Maximum Entropy Analysis of the Spectral Functions in Lattice QCD
• 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
• The QCD phase structure at finite temperature and density
• Domain wall QCD with physical quark masses
• Physical Results from 2+1 Flavor Domain Wall QCD and SU(2) Chiral Perturbation Theory
• Explanation and Prediction of Observables using Continuum Strong QCD
• QCD at finite temperature and chemical potential from Dyson-Schwinger equations
• Landau gauge Yang-Mills correlation functions
• Non-perturbative quark, gluon and meson correlators of unquenched QCD
• A novel Bayesian approach to spectral function reconstruction
• Light mesons in QCD and unquenching effects from the 3PI effective action
• Gaussian Processes and Kernel Methods: A Review on Connections and Equivalences
• Quark flavour effects on gluon and ghost propagators
• Three-point vertices in Landau-gauge Yang-Mills theory
• Process-independent strong running coupling
• QCD phase structure from functional methods
• Ghost-gluon running coupling, power corrections and the determination of ${\Lambda }_{\overline{\mathrm{MS}}}$
• Towards the infrared limit in SU(3) Landau gauge lattice gluodynamics
• Domain Wall QCD with Near-Physical Pions
• Exploratory study of three-point Green's functions in Landau-gauge Yang-Mills theory
• 2+1 flavor domain wall QCD on a (2 fm)^3 lattice: light meson spectroscopy with Ls = 16
• Nevanlinna Analytical Continuation
• Spectral functions of confined particles
• Infrared Behavior of the Gluon Propagator on a Large Volume Lattice
• Transport Coefficients in Yang--Mills Theory and QCD
• Reconstructing the gluon
• When Gaussian Process Meets Big Data: A Review of Scalable GPs
• Effective charge from lattice QCD
• Artificial Neural Network Approach to the Analytic Continuation Problem
• Fully coupled functional equations for the quark sector of QCD
• Gluon spectral functions and transport coefficients in Yang--Mills theory
• The strong running coupling from the gauge sector of Domain Wall lattice QCD with physical quark masses
• Correlation functions of Landau gauge Yang-Mills theory
• Unquenching the gluon propagator with Schwinger-Dyson equations
• Gluon propagator and three-gluon vertex with dynamical quarks
• Mobius Fermions: Improved Domain Wall Chiral Fermions
• Reconstructing the thermal Green functions at real times from those at imaginary times
• Analytic continuation via domain-knowledge free machine learning
• Discretization effects on renormalized gauge-field Green's functions, scale setting and gluon mass
• Further Evidence For Zero Crossing On The Three Gluon Vertex
• Spectral Reconstruction with Deep Neural Networks
• Analytical Continuation of Matrix-Valued Functions: Carathéodory Formalism
• The decay constants ${\mathbf{f}}_{\mathbf{D}}$ and ${\mathbf{f}}_{{\mathbf{D}}_{\mathbf{s}}}$ in the continuum limit of ${\mathbf{N}}_{\mathbf{f}}=2+1$ domain wall lattice QCD
• Does The Lattice Zero Momentum Gluon Propagator for Pure Gauge SU(3) Yang-Mills Theory Vanish in the Infinite Volume Limit?
• Recent developments in bound-state calculations using the Dyson-Schwinger and Bethe-Salpeter equations
• Ghost spectral function from the spectral Dyson-Schwinger equation
• Spectral functions in the ${\varphi }^4$-theory from the spectral DSE
• Spectral representation of lattice gluon and ghost propagators at zero temperature
• Gluon-propagator functional form in the Landau gauge in SU(3) lattice QCD: Yukawa-type gluon propagator and anomalous gluon spectral function
• Ghost dynamics in the soft gluon limit
• Asymptotic behavior of the ghost propagator in SU3 lattice gauge theory
• 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
• Complex poles and spectral function of Yang-Mills theory
• Bayesian inference of non-positive spectral functions in quantum field theory
• Reconstructing confined particles with complex singularities
• Infrared Gluon Propagator from lattice QCD: results from large asymmetric lattices
• Complex poles and spectral functions of Landau gauge QCD and QCD-like theories
• Parton distribution functions from lattice QCD using Bayes-Gauss-Fourier transforms
• Some remarks on the spectral functions of the Abelian Higgs Model
• Non-perturbative constraints on the quark and ghost propagators
• 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
• On general ultraviolet properties of a class of confining propagators
• On the zero-crossing of the three-gluon Green's function from lattice simulations

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