ABSTRACT

Functions

7.1 Introduction

Analogous to the generalizations of the family of gamma and beta functions,

extensions of the Riemann zeta function are presented, for which the usual

properties and representations are naturally and simply extended. Analo-

gous to these extensions, the extended Hurwitz zeta functions are introduced.

Hurwitz-type formulae are also proved. Because there are innitely many

new functions or generalizations possible for well-known functions, one needs

some clear-cut criteria to determine whether a given extension is worthwhile

or not. If it arises in diverse problems or interesting relations turn up between

it and other functions, or new insights are provided for the original functions,

or particularly elegant results can be found for the new function, it would be

worthwhile. In the present case, we do nd natural extensions of the previous

results, obtain new results for the extensions and expect that there will be a

wider applicability of these extended zeta functions. We use integral repre-

sentations of the zeta function to extend them analogously to the generalized

gamma function. We also apply our extension procedure to the Hurwitz zeta

function, (; q), and obtain the corresponding extensions for it. The asymp-

totic representations for these functions for small values of the parameter are

proved as well. Hurwitz-type formulae for the corresponding loop integrals

are also proved. In the rst three sections, we present standard results about

the Bernoulli numbers and polynomials and the Riemann zeta functions and

its zeros. We state the standard results about the Hurwitz zeta function in

Section 7.4. The rest of the sections deal with the extended Riemann and

Hurwitz zeta functions.