Ml. Gerver et Ea. Kudryavtseva, A THEOREM ON ORDER RELATIONS GENERATED BY TOTALLY POSITIVE KERNELS, Sbornik. Mathematics, 186(9-10), 1995, pp. 1241-1269
This paper is a result of reflections on a theorem on 'sums of hyperbo
lae'(1) needed in mathematical geophysics. This theorem and several un
expected corollaries of it do not seem very plausible at first sight.
The first proof of the theorem did not dispel this impression: the rea
sons why, it was true remained obscure. The explanation was found in t
he properties of the Cauchy kernel C(s, x) = 1/(s+x). In this paper th
e original theorem on 'hyperbolae' is established as a particular case
of a general result holding for a certain class G of totally positive
kernels which contains C(s, x).