English
Related papers

Related papers: Multipoint correlation functions: spectral represe…

200 papers

Schwinger Keldysh field theory is a widely used paradigm to study non-equilibrium dynamics of quantum many-body systems starting from a thermal state. We extend this formalism to describe non-equilibrium dynamics of quantum systems starting…

Statistical Mechanics · Physics 2019-03-13 Ahana Chakraborty , Pranay Gorantla , Rajdeep Sensarma

Exotic phases of matter can emerge from strong correlations in quantum many-body systems. Quantum gas microscopy affords the opportunity to study these correlations with unprecedented detail. Here we report site-resolved observations of…

We construct a nonperturbative nonequilibrium theory for graphene electrons interacting via the instantaneous Coulomb interaction by combining the functional renormalization group method with the nonequilibrium Keldysh formalism. The…

Mesoscale and Nanoscale Physics · Physics 2017-03-15 Christian Fräßdorf , Johannes E. M. Mosig

We introduce a quasiclassical Green function approach describing the unitary yet irreversible dynamics of quantum systems effectively acting as their own environment. Combining a variety of concepts of quantum many-body theory, notably the…

Mesoscale and Nanoscale Physics · Physics 2025-09-09 Alexander Altland , Kun Woo Kim , Tobias Micklitz

We review methods that allow one to detect and characterise quantum correlations in many-body systems, with a special focus on approaches which are scalable. Namely, those applicable to systems with many degrees of freedom, without…

Quantum Physics · Physics 2023-09-28 Irénée Frérot , Matteo Fadel , Maciej Lewenstein

Accurately describing many-body effects in multi-orbital systems remains a major challenge in theoretical condensed matter physics. At present, there is a significant methodological gap between the numerical tools used in ab initio…

Strongly Correlated Electrons · Physics 2025-12-16 Evgeny A. Stepanov

We describe recent progress in the statistical mechanical description of many-body systems via machine learning combined with concepts from density functional theory and many-body simulations. We argue that the neural functional theory by…

Soft Condensed Matter · Physics 2024-04-04 Florian Sammüller , Sophie Hermann , Matthias Schmidt

The Larkin-Migdal approach to a cold superfluid Fermi liquid is generalized for a non-equilibrium system. The Schwinger-Keldysh diagram technique is applied. The developed formalism is applicable to the pairing in the states with arbitrary…

Nuclear Theory · Physics 2015-03-17 E. E. Kolomeitsev , D. N. Voskresensky

A self-consistent many-body approach is proposed to build a first-principles crystal field theory, where crystal field parameters are calculated ab initio. Many-body theory is used to write the energy of the interacting system as a function…

Strongly Correlated Electrons · Physics 2010-09-17 Christian Brouder

We give an introductory account of the recent hyperdensity functional theory for the equilibrium statistical mechanics of soft matter systems [F. Samm\"uller et al., Phys. Rev. Lett. 133, 098201 (2024); 10.1103/PhysRevLett.133.098201].…

Soft Condensed Matter · Physics 2025-02-27 Florian Sammüller , Matthias Schmidt

A numerical approach is presented that allows to compute nonequilibrium steady state properties of strongly correlated quantum many-body systems. The method is imbedded in the Keldysh Green's function formalism and is based upon the idea of…

Strongly Correlated Electrons · Physics 2011-10-26 Michael Knap , Wolfgang von der Linden , Enrico Arrigoni

I review many-body effects on the resistivity of a multiorbital system beyond Landau's Fermi-liquid (FL) theory. Landau's FL theory succeeds in describing electronic properties of some correlated electron systems at low temperatures.…

Strongly Correlated Electrons · Physics 2015-06-17 Naoya Arakawa

We present a theoretical framework for higher-order correlation functions involving multiple times and multiple points in a classical, many-body system. Such higher-order correlation functions have attracted much interest recently in the…

Statistical Mechanics · Physics 2009-11-07 Ramses van Zon , Jeremy Schofield

The description of dynamics of strongly correlated quantum matter is a challenge, particularly in physical situations where a quasiparticle description is absent. In such situations, however, the many-body Kubo formula from linear response…

Strongly Correlated Electrons · Physics 2022-05-11 Aavishkar A. Patel , Hitesh J. Changlani

We study spectral properties of quantum many-body Hamiltonians through a subsystem-based framework. Given a Hamiltonian of the form $H = \sum_{X \subseteq \Lambda} \Phi(X)$ acting on a tensor product Hilbert space, we associate to each…

Quantum Physics · Physics 2026-05-05 MD Nahidul Hasan Sabit

Many-body localization (MBL) in a one-dimensional Fermi Hubbard model with random on-site interactions is studied. While for this model all single-particle states are trivially delocalized, it is shown that for sufficiently strong…

Disordered Systems and Neural Networks · Physics 2016-11-22 Yevgeny Bar Lev , David R. Reichman , Yoav Sagi

Computing dynamical properties of strongly interacting quantum many-body systems poses a major challenge to theoretical approaches. Usually, one has to resort to numerical analytic continuation of results on imaginary frequencies, which is…

Quantum Gases · Physics 2026-02-12 Christian H. Johansen , Bernhard Frank , Johannes Lang

A recent mode coupling theory of higher-order correlation functions is tested on a simple hard-sphere fluid system at intermediate densities. Multi-point and multi-time correlation functions of the densities of conserved variables are…

Statistical Mechanics · Physics 2009-11-07 Ramses van Zon , Jeremy Schofield

A many-body theory approach is developed for the problem of positron-atom scattering and annihilation. Strong electron-positron correlations are included non-perturbatively through the calculation of the electron-positron vertex function.…

Atomic Physics · Physics 2007-05-23 G. F. Gribakin , J. Ludlow

A generalized fluctuational electrodynamics-based many-body approach for calculating near-field radiative heat transfer (NFRHT) between nonspherical dipoles is proposed. The geometric parameters of nonspherical dipoles are implemented in…

Applied Physics · Physics 2025-09-10 Lindsay P. Walter , Mathieu Francoeur