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We develop a semiclassical density functional theory in the context of quantum dots. Coulomb blockade conductance oscillations have been measured in several experiments using nanostructured quantum dots. The statistical properties of these…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Denis Ullmo , Tatsuro Nagano , Steven Tomsovic , Harold U. Baranger

In this review, we discuss recent developments concerning efficient calculations of multi-loop multi-leg scattering amplitudes. Inspired by the remarkable properties of the Loop-Tree Duality (LTD), we explain how to reconstruct an integrand…

High Energy Physics - Phenomenology · Physics 2021-09-30 German F. R. Sborlini

We develop novel methods to compute auto-correlation functions, or power spectral densities, for chaotic dynamical systems generated by an inverse method whose starting point is an invariant distribution and a two-form. In general, the…

Chaotic Dynamics · Physics 2008-09-02 Gerald Guralnik , Zachary Guralnik , Cengiz Pehlevan

The phase transition patterns displayed by a model of two coupled complex scalar fields are studied at finite temperature and chemical potential. Possible phenomena like symmetry persistence and inverse symmetry breaking at high…

High Energy Physics - Phenomenology · Physics 2023-02-24 Manuella C. Silva , Rudnei O. Ramos , Ricardo L. S. Farias

We construct a program to calculate Feynman amplitudes at finite temperature in the real time Keldysh formalism using the symbolic manipulation program {\it Mathematica}. As an example, the usefulness of this program is demonstrated by…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. E. Carrington , Hou Defu , A. Hachkowski , D. Pickering , J. C. Sowiak

The thermodynamic approach to density functional theory (DFT) is used to derive a versatile theoretical framework for the treatment of finite-temperature (and in the limit, zero temperature) Bose-Einstein condensates (BECs). The simplest…

Quantum Gases · Physics 2015-05-20 Nathan Argaman , Y. B. Band

There has been significant progress in our understanding of finite-temperature field theory over the past decade. In this paper, we review the progress in perturbative thermal field theory focusing on thermodynamic quantities. We first…

High Energy Physics - Phenomenology · Physics 2009-09-29 Jens O. Andersen , M. Strickland

A diagrammatic kinetic theory of density fluctuations in simple dense liquids at long times, described in the preceding paper, is applied to a high density Lennard-Jones liquid to calculate various equilibrium time correlation functions.…

Statistical Mechanics · Physics 2015-06-18 Kevin R. Pilkiewicz , Hans C. Andersen

Spectral density functions quantify how environmental modes couple to quantum systems and govern their open dynamics. Inferring such frequency-dependent functions from time-domain measurements is an ill-conditioned inverse problem. Here, we…

Two-point correlation functions are ubiquitous tools of modern cosmology, appearing in disparate topics ranging from cosmological inflation to late-time astrophysics. When the background spacetime is maximally symmetric, invariance…

General Relativity and Quantum Cosmology · Physics 2017-02-22 Oton H. Marcori , Thiago S. Pereira

We investigate the theory of thermodynamic formalism from the perspective of computable analysis, with a special focus on the computability of equilibrium states. Specifically, we develop two complementary general approaches to verify the…

Dynamical Systems · Mathematics 2025-12-18 Ilia Binder , Qiandu He , Zhiqiang Li , Xianghui Shi

The Frenkel exciton Hamiltonian is at the heart of many simulations of excitation energy transfer in molecular aggregates. It separates the aggregate into Coulomb-coupled monomers. Here it is shown that the respective parameters, i.e.…

Chemical Physics · Physics 2015-06-18 Per-Arno Plötz , Thomas Niehaus , Oliver Kühn

The equations of time-dependent density functional theory are derived, via the expression for the quantum weak value, from ring polymer quantum theory using a symmetry between time and imaginary time. The imaginary time path integral…

Quantum Physics · Physics 2025-03-21 Russell B. Thompson , Zarin Tasneem , Yves Caudano

Minkowski functionals quantify the morphology of smooth random fields. They are widely used to probe statistical properties of cosmological fields. Analytic formulae for ensemble expectations of Minkowski functionals are well known for…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-27 Pravabati Chingangbam , Fazlu Rahman

The Feynman-Vernon path integral formalism is used to derive the density matrix of a quantum oscillator that is linearly coupled to an environmental reservoir. Although low-temperature reservoirs thermalize the oscillator to the usual…

General Physics · Physics 2014-12-15 George E. Cragg

A quantum-field approach for describing many-particle Fermi systems at finite temperatures and with spontaneously broken symmetry has been proposed. A generalized model of self-consistent field (SCF), which allows one to describe the states…

Statistical Mechanics · Physics 2013-03-21 Yu. M. Poluektov

A well-known difficulty of perturbative approaches to quantum field theory at finite temperature is the necessity to address theoretical constraints that are not present in the vacuum theory. In this work, we use lattice simulations of…

High Energy Physics - Phenomenology · Physics 2024-08-30 Peter Lowdon , Owe Philipsen

The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation…

High Energy Physics - Lattice · Physics 2015-06-25 I. Wetzorke , F. Karsch , E. Laermann , P. Petreczky , S. Stickan

We present an approach based on density-functional theory for the calculation of fundamental gaps of both finite and periodic two-dimensional (2D) electronic systems. The computational cost of our approach is comparable to that of total…

Materials Science · Physics 2021-08-11 Alberto Guandalini , Alice Ruini , Esa Räsänen , Carlo Andrea Rozzi , Stefano Pittalis

We develop a description of fermionic superfluids in terms of an effective field theory for the pairing order parameter. Our effective field theory improves on the existing Ginzburg - Landau theory for superfluid Fermi gases in that it is…

Quantum Gases · Physics 2015-06-05 S. N. Klimin , J. Tempere , G. Lombardi , J. T. Devreese