Variational method for the free-energy approximation of generalized anharmonic oscillators

1993 ◽  
Vol 47 (2) ◽  
pp. 838-846 ◽  
Author(s):  
K. Vlachos
2017 ◽  
Vol 62 (5) ◽  
pp. 240-243 ◽  
Author(s):  
N. E. Dubinin ◽  
V. V. Filippov ◽  
A. A. Yuryev ◽  
N. A. Vatolin

1967 ◽  
Vol 24 (13) ◽  
pp. 711-712
Author(s):  
W.R. Bandy ◽  
C.R. Haden ◽  
T.D. Shockley

1983 ◽  
Vol 38 (4) ◽  
pp. 473-476 ◽  
Author(s):  
Alejandro M. Mesón ◽  
Francisco M. Fernández ◽  
Eduardo A. Castro

It is shown that accurate upper and lower bounds to the eigenvalues of anharmonic oscillators can be obtained by means of the Rayleigh-Ritz variational method and two trigonometric basis sets of functions which satisfy Dirichlet and Von Neumann boundary conditions. Numerical results show that the Dirichlet basis set is more appropriate than the harmonic oscillator one for calculating eigenvalues and the value of eigenfunctions at the origin.


2009 ◽  
Vol 23 (01) ◽  
pp. 113-123 ◽  
Author(s):  
G. H. BORDBAR ◽  
M. J. KARIMI ◽  
J. VAHEDI

We have investigated some of the thermodynamic properties of spin-polarized liquid 3 He at finite temperature using the lowest order constrained variational method. For this system, the free energy, entropy and pressure are calculated for different values of the density, temperature and polarization. We have also presented the dependence of specific heat, saturation density and incompressibility on temperature and polarization.


BIBECHANA ◽  
2012 ◽  
Vol 9 ◽  
pp. 7-12
Author(s):  
BK Singh ◽  
Sudhir Singh

The Gibbs-Bogoliubov variational method has been considered to study the Helmholtz free energy of liquid alkali metals (Na, K, Rb and Cs) as a function of temperature, using Heine Abarenkov type model potential with Hubbard-Sham exchange and correlation function. The computed values are in very good agreement with experimental observations. DOI: http://dx.doi.org/10.3126/bibechana.v9i0.7144 BIBECHANA 9 (2013) 7-12


1981 ◽  
Vol 59 (10) ◽  
pp. 1291-1295 ◽  
Author(s):  
Chin-Kun Hu ◽  
Wen-Den Chen ◽  
Yu-Ming Shih ◽  
Dong-Chung Jou ◽  
C. K. Pan ◽  
...  

We apply a modified Kadanoff's variational method to calculate the lower bound zero-field free energies and their derivatives for an Ising model on the simple cubic lattice. We find a critical point at Kc = 0.2393769 with precision ±10−7.


1968 ◽  
Vol 23 (11) ◽  
pp. 1822-1833
Author(s):  
W. Schattke

Starting from the BCS-Theory, an upper bound for the free energy is obtained by a combination of a variational method and perturbation theory. The variational equations obtained are non-local. The parameters of the perturbation calculation are the vector potential and the spatial variations of the order parameter, which have to be small. Boundary conditions are set for the case of diffuse reflection and pair-breaking at the surface. As an example, the superconducting plate is discussed.


1984 ◽  
Vol 71 (6) ◽  
pp. 1413-1415 ◽  
Author(s):  
A. Oguchi

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