We have previously formulated a program for deducing the intervals of oscillations in the
solutions of ordinary second-order linear homogeneous differential equations. In this work …

We establish sharp (or'refined') comparison theorems for the Klein–Gordon equation. We
show that the condition V a≤ V b, which leads to E a≤ E b, can be replaced by the weaker …

The classic comparison theorem of quantum mechanics states that if two potentials are
ordered then the corresponding energy eigenvalues are similarly ordered, that is to say if …

A single fermion is bound by a softcore central Coulomb potential $ V (r)=-{v}/{(r^ q+ b^
q)^{\frac {1}{q}}} $, v> 0, b> 0, q⩾ 1, in d> 1 spatial dimensions. Envelope theory is used to …

In this paper computational algorithms are presented to compute the eigenvalues of
Schrödinger operators with definite and indefinite weights. The algorithms are based on …

This paper establishes a new criteria for obtaining a sequence of upper and lower bounds
for the ground state eigenvalue of Schr ö dinger equation−∆ ψ (r)+ V (r) ψ (r)= Eψ (r) in N …

We first study bound-state solutions of the Klein--Gordon equation φ"(x)=[m^ 2-[(EV (x))]^ 2]
φ (x), for vector potentials which in one spatial dimension have the form V (x)= vf (x), where f …

A single particle is bound by an attractive central potential and obeys the Dirac equation in d
spatial dimensions. The Coulomb potential is one of the few examples for which exact …