English
Related papers

Related papers: Generating functionals method of N.N.Bogolyubov an…

200 papers

We develop an approximate formalism suitable for performing simulations of the thermal dynamics of interacting Bose gases. The method is based on the observation that when the lowest energy modes of the Bose field operator are highly…

Condensed Matter · Physics 2009-11-07 M. J. Davis , R. J. Ballagh , K. Burnett

We describe here an experimental method that permits to compute a good candidate for the closed form of a generating function if we know the first few terms of a series. The method is based on integer relations algorithms and uses either…

Number Theory · Mathematics 2009-12-02 Simon Plouffe

The thermodynamic properties of superconducting electrons are usually studied by means of the quasi-particles distribution; but in this approach, the ground state energy and the dependence of the chemical potential on the electron density…

Superconductivity · Physics 2017-06-09 Enore Guadagnini

The existing formalism used to compute the operator overlaps necessary to carry out generator coordinate method calculations using a set of Hartree- Fock- Bogoliubov wave functions, is generalized to the case where each of the HFB states…

Nuclear Theory · Physics 2022-03-14 L. M. Robledo

We introduce a non-commutative generalization of the Gross-Pitaevskii equation for one-dimensional quantum gasses and quantum liquids. This generalization is obtained by applying the time-dependent variational principle to the variational…

We argue that one can model deviations from the ensemble average in non-equilibrium statistical mechanics by promoting the Boltzmann equation to an equation in terms of {\em functionals} , representing possible candidates for phase space…

Statistical Mechanics · Physics 2024-03-13 Giorgio Torrieri

In this manuscript we introduce numerical Gaussian process Kalman filtering (GPKF). Numerical Gaussian processes have recently been developed to simulate spatiotemporal models. The contribution of this paper is to embed numerical Gaussian…

Machine Learning · Statistics 2020-05-12 Armin Küper , Steffen Waldherr

A self-contained pedagogical introduction to the functional Schr\"{o}dinger picture method of many-body theory is given at a level suitable for graduate students and also for many-body physicists who have not been exposed to the functional…

Strongly Correlated Electrons · Physics 2007-05-23 Chul Koo Kim , Sang Koo You

A phase-space distribution function of the steady state in galaxy models that admits regular orbits overall in the phase-space can be represented by a function of three action variables. This type of distribution function in Galactic models…

Astrophysics of Galaxies · Physics 2015-06-19 Haruhiko Ueda , Takuji Hara , Naoteru Gouda , Taihei Yano

We present a novel extension of multi-output Gaussian processes for handling heterogeneous outputs. We assume that each output has its own likelihood function and use a vector-valued Gaussian process prior to jointly model the parameters in…

Machine Learning · Statistics 2019-01-04 Pablo Moreno-Muñoz , Antonio Artés-Rodríguez , Mauricio A. Álvarez

The theory of real-time quantum many-body dynamics as put forward in Ref. [arXiv:0710.4627] is evaluated in detail. The formulation is based on a generating functional of correlation functions where the Keldysh contour is closed at a given…

Quantum Gases · Physics 2011-02-09 Thomas Gasenzer , Stefan Kessler , Jan M. Pawlowski

We define discrete generating series for arbitrary functions \( f \colon \mathbb{Z}^n \rightarrow \mathbb{C} \) and derive functional relations that these series satisfy. For linear difference equations with constant coefficients, we…

Classical Analysis and ODEs · Mathematics 2025-05-01 Vitaly Alekseev , Tom Cuchta , Alexander Lyapin

Single-particle resonances are crucial for exotic nuclei near and beyond the drip lines. Since the majority of nuclei are deformed, the interplay between deformation and orbital structure near threshold becomes very important and can lead…

Nuclear Theory · Physics 2020-02-05 T. -T. Sun , L. Qian , C. Chen , P. Ring , Z. P. Li

The Smoluchowsky equation for a system of interacting Brownian particles in a temperature gradient is derived from the Kramers equation by means of a multiple time-scale method. The interparticle interactions are assumed to be represented…

Statistical Mechanics · Physics 2009-11-11 Cristobal Lopez , Umberto Marini Bettolo Marconi

In this work, we study a new spectral Petrov-Galerkin approximation of space-time fractional reaction-diffusion equations with viscosity terms built by Riemann-Liouville fractional-order derivatives. The proposed method is reliant on…

Numerical Analysis · Mathematics 2019-11-26 Zhe Yu , Boying Wu , Jiebao Sun , Wenjie Liu

This work shows that for rational multivariate functions, the Kolmogorov Superposition Theorem (KST) involves several single-variable functions, which can be written down by inspection. In other words, no computation is required for…

Numerical Analysis · Mathematics 2026-05-11 A. C. Antoulas , I. V. Gosea , C. Poussot-Vassal

Simulations of interacting electrons and bosons out of equilibrium, starting from first principles and aiming at realistic multiscale scenarios, is a grand theoretical challenge. Here, using the formalism of nonequilibrium Green's functions…

Strongly Correlated Electrons · Physics 2022-04-06 Yaroslav Pavlyukh , Enrico Perfetto , Daniel Karlsson , Robert van Leeuwen , Gianluca Stefanucci

The theoretical framework for higher-order correlation functions involving multiple times and multiple points in a classical, many-body system developed by Van Zon and Schofield [Phys. Rev. E 65, 011106 (2002)] is extended here to include…

Statistical Mechanics · Physics 2007-05-23 Ramses van Zon , Jeremy Schofield

For the calculation of the partition function $\mathcal{Z}$ of small, isolated and interacting many body systems an improvement with respect to previous formulations is presented. By including anharmonicities and employing a variational…

Nuclear Theory · Physics 2009-11-10 Christian Rummel , Helmut Hofmann

The stochastic method based on the influence functional formalism introduced in an earlier paper to treat particle creation in near-uniformly accelerated detectors and collapsing masses is applied here to treat thermal and near-thermal…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Don Koks , B. L. Hu , Andrew Matacz , Alpan Raval