English
Related papers

Related papers: Rational approximation to Thomas-Fermi equations

200 papers

We report on an original method, due to Majorana, leading to a semi-analytical series solution of the Thomas-Fermi equation, with appropriate boundary conditions, in terms of only one quadrature. We also deduce a general formula for such a…

Atomic Physics · Physics 2009-11-07 Salvatore Esposito

In heavy atoms and molecules, on the distances $a \gg Z^{-1}$ from all of the nuclei (with a charge $Z_m$) we prove that $\rho_\Psi (x)$ is approximated in $L^p$-norm, by the Thomas-Fermi density.

Spectral Theory · Mathematics 2020-04-02 Victor Ivrii

Two approaches for the efficient rational approximation of the Fermi-Dirac function are discussed: one uses the contour integral representation and conformal mapping and the other is based on a version of the multipole representation of the…

Numerical Analysis · Mathematics 2009-12-14 Lin Lin , Jianfeng Lu , Lexing Ying , E Weinan

The main purpose of the paper is to present some powerful data on the advantage of the rational approximation procedure based on Hermite-Pad\'e polynomials over the Pad\'e approximation procedure. The first part of the paper is devoted to…

Complex Variables · Mathematics 2023-12-08 Egor O. Dobrolyubov , Nikolay R. Ikonomov , Leonid A. Knizhnerman , Sergey P. Suetin

We investigate the rational approximation of fractional powers of unbounded positive operators attainable with a specific integral representation of the operator function. We provide accurate error bounds by exploiting classical results in…

Numerical Analysis · Mathematics 2024-03-19 Lidia Aceto , Paolo Novati

An accurate non-gradient-expansion based correction to Thomas--Fermi is developed using solvable model. The used model is a system of $N$ non-interacting electrons moving independently in the Coulomb field of the nuclear charge. The…

Quantum Physics · Physics 2015-06-04 Alexey Sergeev , Raka Jovanovic , Sabre Kais , Fahhad H Alharbi

We consider a Fermi-Pasta-Ulam-Tsingou lattice with randomly varying coefficients. We discover a relatively simple condition which when placed on the nature of the randomness allows us to prove that small amplitude/long wavelength solutions…

Analysis of PDEs · Mathematics 2023-08-14 Joshua A. McGinnis , J. Douglas Wright

The purpose of this paper is to derive sharp asymptotics of the ground state energy for the heavy atoms and molecules in the relativistic settings, with the self-generated magnetic field, and, in particular, to derive relativistic Scott…

Spectral Theory · Mathematics 2017-08-28 Victor Ivrii

The Schwinger quantum correction to the classic Thomas-Fermi atom is directly derived by solving for the latter without recourse to a modeling after the harmonic oscillator potential and without solving for the particle density.

Quantum Physics · Physics 2007-06-13 Edouard B. Manoukian , Parut Bantitadawit

The Thomas-Fermi approximation is a powerful method that has been widely used to describe atomic structures, finite nuclei, and nonuniform matter in supernovae and neutron-star crusts. Nonuniform nuclear matter at subnuclear density is…

Nuclear Theory · Physics 2025-08-05 Shuying Li , Hong Shen , Jinniu Hu

Quantum corrections to Thomas-Fermi (TF) theory are investigated for noninteracting one-dimensional fermions with known uniform semiclassical approximations to the density and kinetic energy. Their structure is analyzed, and contributions…

Quantum Gases · Physics 2017-03-15 Raphael F. Ribeiro , Kieron Burke

By using the scaling method we derive the virial theorem for the relativistic mean field model of nuclei treated in the Thomas-Fermi approach. The Thomas-Fermi solutions statisfy the stability condition against scaling. We apply the…

Nuclear Theory · Physics 2010-12-23 S. K. Patra , M. Centelles , X. Vinas , M. Del Estal

This letter aims at resolving the issues raised in the recent short communication [1] and answered by [2] by proposing a systematic approximation scheme based on non-mapped shape functions, which both allows to fully exploit the unique…

Numerical Analysis · Computer Science 2011-07-20 Stephane PA Bordas , Sundararajan Natarajan

As is well known, in mathematics, any function could be approximated by the Pad\'e approximant. The Pad\'e approximant is the best approximation of a function by a rational function of given order. In fact, the Pad\'e approximant often…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-05 Hao Wei , Xiao-Peng Yan , Ya-Nan Zhou

We briefly review the Thomas-Fermi statistical model of atoms in the classical non-relativistic formulation and in the generalised finite-nucleus relativistic formulation. We then discuss the classical generalisation of the model to finite…

Astrophysics · Physics 2017-08-23 G. Bertone , R. Ruffini

The method of self-similar factor approximants is shown to be very convenient for solving different evolution equations and boundary-value problems typical of physical applications. The method is general and simple, being a straightforward…

Mathematical Physics · Physics 2009-11-13 E. P. Yukalova , V. I. Yukalov , S. Gluzman

Using the universal torsor method due to Salberger, we study the approximation of a general fixed point by rational points on split toric varieties. We prove that under certain geometric hypothesis the best approximations (in the sense of…

Number Theory · Mathematics 2025-08-05 Zhizhong Huang

A Thomas-Fermi-Weizsaecker type theory is constructed, by means of which we are able to give a relatively simple proof of the stability of relativistic matter. Our procedure has the advantage over previous ones in that the critical value of…

Condensed Matter · Physics 2007-05-23 E. H. Lieb , M. Loss , H. Siedentop

We proposed a formally exact, probabilistic method to assess the validity of the Thomas-Fermi potential for three-dimensional condensed matter systems where electron dynamics is constrained to the Fermi surface. Our method, which relies on…

Materials Science · Physics 2024-06-25 Gionni Marchetti

The purpose of this paper is to derive sharp asymptotics of the ground state energy for the heavy atoms and molecules in the relativistic settings, and, in particular, to derive relativistic Scott correction term and also Dirac, Schwinger…

Spectral Theory · Mathematics 2017-08-24 Victor Ivrii