English
Related papers

Related papers: Real time correlation functions and the functional…

200 papers

We present first results on the calculation of fermionic spectral functions from analytically continued flow equations within the Functional Renormalization Group approach. Our method is based on the same analytic continuation from…

High Energy Physics - Phenomenology · Physics 2018-11-14 Ralf-Arno Tripolt , Johannes Weyrich , Lorenz von Smekal , Jochen Wambach

We employ the density matrix renormalization group to construct the exact time-dependent exchange correlation potential for an impurity model with an applied transport voltage. Even for short-ranged interaction we find an infinitely…

Mesoscale and Nanoscale Physics · Physics 2017-09-13 Peter Schmitteckert , Michael Dzierzawa , Peter Schwab

We develop a prescription for computing real-time correlation functions defined on a Schwinger-Keldysh contour for non-equilibrium systems using gravity. The prescription involves a new analytic continuation procedure in a black hole…

High Energy Physics - Theory · Physics 2018-12-21 Paolo Glorioso , Michael Crossley , Hong Liu

Dynamic equations for quantum fields far from equilibrium are derived by use of functional renormalisation group techniques. The obtained equations are non-perturbative and lead substantially beyond mean-field and quantum Boltzmann type…

Other Condensed Matter · Physics 2008-11-27 Thomas Gasenzer , Jan M. Pawlowski

One of the most important quantities characterizing the microscopic properties of quantum systems are dynamical correlation functions. These correlations are obtained by time-evolving a perturbation of an eigenstate of the system, typically…

Quantum Physics · Physics 2025-02-26 Reinis Irmejs , Raul A. Santos

We develop a perturbative renormalization-group method in real time to describe nonequilibrium properties of discrete quantum systems coupled linearly to an environment. We include energy broadening and dissipation and develop a…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Herbert Schoeller , Jürgen König

We present a Keldysh nonlinear sigma-model approach to the renormalization group analysis of the disordered electron liquid. We include both the Coulomb interaction and Fermi-liquid type interactions in the singlet and triplet channels into…

Mesoscale and Nanoscale Physics · Physics 2014-11-20 G. Schwiete , A. M. Finkel'stein

We investigate proposals of how the form factor approach to compute correlation functions at zero temperature can be extended to finite temperature. For the two-point correlation function we conclude that the suggestion to use the usual…

High Energy Physics - Theory · Physics 2015-06-26 O. A. Castro-Alvaredo , A. Fring

We calculate current-current correlation functions and find an expression for the zero-frequency noise of multiterminal systems driven by harmonically time-dependent voltages within the Keldysh non-equilibrium Green's functions formalism.…

Mesoscale and Nanoscale Physics · Physics 2012-08-02 Alvaro Caso , Liliana Arrachea , Gustavo S. Lozano

We investigate the RG-time integration of the effective potential in the functional renormalization group in the presence of spontaneous symmetry breaking and its subsequent convexity restoration on the example of a scalar theory in $d=3$.…

High Energy Physics - Theory · Physics 2023-06-21 Friederike Ihssen , Franz R. Sattler , Nicolas Wink

We propose a numerical spectral reconstruction workflow for high-temperature gauge theories that incorporates elements of semi-classical real-time evolution directly into standard lattice QCD simulations via high-temperature dimensional…

High Energy Physics - Lattice · Physics 2025-12-30 P. V. Buividovich , B. Hind

In this paper we provide an alternative method to compute correlation functions in the in-in formalism, with a modified set of Feynman rules to compute loop corrections. The diagrammatic expansion is based on an iterative solution of the…

High Energy Physics - Theory · Physics 2014-01-17 Marcello Musso

Linearizing the appropriate kinetic equation we derive general response functions including selfconsistent mean fields or density functionals and collisional dissipative contributions. The latter ones are considered in relaxation time…

Nuclear Theory · Physics 2008-12-18 Klaus Morawetz , Uwe Fuhrmann

Quantum Chromodynamics in two spacetime dimensions is investigated with the Functional Renormalization Group. We use a functional formulation with covariant gauge fixing and derive Renormalization Group flow equations for the gauge…

High Energy Physics - Phenomenology · Physics 2025-05-06 Eric Oevermann , Adrian Koenigstein , Stefan Floerchinger

We introduce a general class of generating functionals for the calculation of quantum-mechanical expectation values of arbitrary functionals of fluctuating paths with fixed end points in configuration or momentum space. The generating…

Quantum Physics · Physics 2009-10-31 Hagen Kleinert , Axel Pelster , Michael Bachmann

We review various theoretical methods that have been used in recent years to calculate dynamical correlation functions of many-body systems. Time-dependent correlation functions and their associated frequency spectral densities are the…

Statistical Mechanics · Physics 2020-06-01 J. Florencio , O. F. de Alcantara Bonfim

We provide a mathematically rigorous Keldysh functional integral for fermionic quantum field theories. We show convergence of a discrete-time Grassmann Gaussian integral representation in the time-continuum limit under very general…

Mathematical Physics · Physics 2025-08-05 Philipp Benjamin Aretz , Manfred Salmhofer

In the framework of the functional renormalization group (FRG) we present a simple truncation scheme for the computation of real-time mesonic n-point functions, consistent with the derivative expansion of the effective action. Via analytic…

High Energy Physics - Phenomenology · Physics 2014-03-19 Kazuhiko Kamikado , Nils Strodthoff , Lorenz von Smekal , Jochen Wambach

We propose to use Ramsey interferometry and single-site addressability, available in synthetic matter such as cold atoms or trapped ions, to measure real-space and time resolved spin correlation functions. These correlation functions…

An exact functional renormalization group flow equation is derived for the divergence functional which is a generalization of the Kullback-Leibler divergence to quantum field theories in the Euclidean domain. It compares distributions with…

High Energy Physics - Theory · Physics 2023-04-11 Stefan Floerchinger