scholarly journals Superradiation of Dirac particles in KN ds black hole

2021 ◽  
Author(s):  
Wen-Xiang Chen

In this article, we process the approximate wave function of the Dirac particle outside the horizon of the KN ds black hole to obtain V, and then derive V (including real and imaginary parts). We deal with the real and imaginary parts separately. When V (real part or imaginary part) has a maximum value, there may be a potential barrier outside the field of view to have a chance to produce superradiation.

An approximate wave function expressed in terms of exponential functions, spherical harmonics, etc., with numerical coefficients has been calculated for the ground state of the beryllium atom . Judged by the energy criterion this gives a more accurate result than the Hartree result which was the best previously known. This has been calculated as a trial of a fresh method of calculating atomic wave functions. A linear combination of Slater determinants is treated by the variational method. The results suggest that this will provide a more powerful and convenient method than has previously been available for atoms with more than two electrons.


1978 ◽  
Vol 56 (7) ◽  
pp. 902-912 ◽  
Author(s):  
Masuo Suzuki ◽  
Seiji Miyashita

An approximate wave function of the ground state of the spin [Formula: see text] XY magnet is derived using a variational method. This wave function yields estimates of the ground state energy and long-range order which agree very well with the results obtained by Betts and Oitmaa by a finite lattice method.


Previous ideas about the way in which hypervirial theorems might be used to improve approximate wave functions are discussed. To provide a firmer foundation for these ideas, a link is established between hypervirial theorems and perturbation theory. It is proved that if the first-order perturbation correction to the expectation value of an arbitrary operator vanishes, then the approximate wave function used satisfies a certain hypervirial theorem. Conversely, if an arbitrary hypervirial theorem is satisfied by the wave function, then it is proved that the expectation values of certain operators have vanishing first-order corrections. Some consequences of the theory as applied to variational wave functions with optimum energy are developed. The results are illustrated by the use of a simple approximate wave function for the ground state of the helium atom.


The equations determining the optimum orbitals in a many-determinant approximate wave function are given and their relation to the total energy considered. As expected, the form of the energy shows that bond energies will be nearly additive in non-conjugated molecules as long as they are not strongly polar, but that this will not be so for conjugated molecules.


2000 ◽  
Vol 61 (5) ◽  
Author(s):  
S. Otranto ◽  
W. R. Cravero ◽  
G. Gasaneo ◽  
F. D. Colavecchia ◽  
C. R. Garibotti

1979 ◽  
Vol 57 (12) ◽  
pp. 2114-2119 ◽  
Author(s):  
Yasuo Tomishima

The new method for obtaining an approximate solution of the Dirac equation proposed by Moore is applied rigorously in zero order to the hydrogenic atom, and the results are compared with the exact solution and with those obtained by Pauli's approximation. It is concluded that up to the order of α2 the three methods give the same energy values, but the higher order contribution included in Moore's method makes the energy worse than Pauli's. Moore's zeroth approximate wave function is also examined.


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