Complex Langevin and other approaches to the sign problem in quantum many-body physics

CE Berger, L Rammelmüller, AC Loheac, F Ehmann… - Physics Reports, 2021 - Elsevier
We review the theory and applications of complex stochastic quantization to the quantum
many-body problem. Along the way, we present a brief overview of a number of ideas that …

Argument for justification of the complex Langevin method and the condition for correct convergence

K Nagata, J Nishimura, S Shimasaki - Physical Review D, 2016 - APS
The complex Langevin method is a promising approach to the complex-action problem
based on a fictitious time evolution of complexified dynamical variables under the influence …

Introductory lectures on lattice QCD at nonzero baryon number

G Aarts - Journal of Physics: Conference Series, 2016 - iopscience.iop.org
These lecture notes contain an elementary introduction to lattice QCD at nonzero chemical
potential. Topics discussed include chemical potential in the continuum and on the lattice; …

Lattice simulations of the QCD chiral transition at real baryon density

S Borsanyi, Z Fodor, M Giordano, SD Katz, D Nogradi… - Physical Review D, 2022 - APS
We use the sign-reweighting method to simulate the QCD chiral transition at real baryon
densities on phenomenologically relevant lattices. This avoids the severe limitations of …

New insights into the problem with a singular drift term in the complex Langevin method

J Nishimura, S Shimasaki - Physical Review D, 2015 - APS
The complex Langevin method aims at performing path integral with a complex action
numerically based on complexification of the original real dynamical variables. One of the …

Equation of state for QCD from lattice simulations

C Ratti - Progress in Particle and Nuclear Physics, 2023 - Elsevier
I will review the state of the art of the equation of state for strongly interacting matter from first
principles. I will discuss results at zero and finite chemical potential. For the latter, I will focus …

New approach to lattice QCD at finite density; results for the critical end point on coarse lattices

M Giordano, K Kapas, SD Katz, D Nogradi… - Journal of High Energy …, 2020 - Springer
A bstract All approaches currently used to study finite baryon density lattice QCD suffer from
uncontrolled systematic uncertainties in addition to the well-known sign problem. We …

Calculating the equation of state of dense quark-gluon plasma using the complex Langevin equation

D Sexty - Physical Review D, 2019 - APS
The pressure and energy density of the quark-gluon plasma at finite baryon chemical
potential are calculated using the complex Langevin equation. The stout smearing …

Controlling complex Langevin simulations of lattice models by boundary term analysis

M Scherzer, E Seiler, D Sexty, IO Stamatescu - Physical Review D, 2020 - APS
One reason for the well-known fact that the complex Langevin (CL) method sometimes fails
to converge or converges to the wrong limit has been identified long ago: it is insufficient …

Complex Langevin simulations and the QCD phase diagram: Recent developments

F Attanasio, B Jäger, FPG Ziegler - The European Physical Journal A, 2020 - Springer
In this review we present the current state-of-the-art on complex Langevin simulations and
their implications for the QCD phase diagram. After a short summary of the complex …