We prove that if two level curves of a harmonic function are convex in the hyperbolic disc then all intermediate level curves are also convex. This item is part of a ...

Sufficient conditions are obtained for a function harmonic in the disk and continuous at a boundary point to have a level curve emanating from the boundary point into the disk. The one-sided ...

IN the correlation of the electrical and spectroscopic properties of a glow discharge in a molecular or atomic gas, the need for a rough quantitative analysis of the kinetics of the excitation of the ...