Turán type inequalities for confluent hypergeometric functions of the second kind

In this paper we deduce some tight Tuŕan type inequalities for Tricomi confluent hy- pergeometric functions of the second kind, which in some cases improve the existing results in the literature. We also give alternative proofs for some already established Tuŕan type inequalities. Moreover, by using these Tuŕan type inequalities, we deduce some new in- equalities for Tricomi confluent hypergeometric functions of the second kind. The key tool in the proof of the Tuŕan type inequalities is an integral representation for a quotient of Tricomi confluent hypergeometric functions, which arises in the study of the infinite divisibility of the Fisher-Snedecor F distribution.