The subject of Prof. Titchmarsh's book is the expansion of an arbitrary function in terms of the eigenfunctions of linear differential equations; to be precise, in terms of functions which satisfy ...

Based on these eigenfunctions there is constructed a special system of functions that already forms the basis. However the obtained system is not already the system of the eigenfunctions of the ...

The spheres in $3-\dim$ Euclidean space are characterized by the fact that they have three 1st eigenfunctions with square sum equal to a constant. This monthly journal, begun in 1950, is devoted ...