ON THE EPSTEIN ZETA FUNCTION
Main Article Content
Abstract
The Epstein zeta function $Z(s)$ is defined for Re$s > 1$ by
\[Z(s)=\sum_{m,n=-\infty, (m, n)\neq (0, 0)}^\infty \frac{1}{(am^2−bnm+cn^2)^s}\]
where $a$, $b$, $c$ are real numbers with $a>0$ and $b^2 - 4ac<0$. $Z(s)$ can be continued analytically to the whole complex plane except for a simple pole at $s =1$. Simple proofs of the functional equation and of the Kronecker "Grenz-formel" for $Z (s)$ are given. The value of $Z(k)$($k =2, 3, \cdots$) is determined in terms of infinite series of the form
\[\sum_{n=1}^\infty\frac{\cot^r n\pi\tau}{n^{2k-1}} (r=1, 2, \cdots, k)\]
where $\tau=(b+\sqrt{b^2-4ac})/2a$.
Article Details

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
References
P. T. Bateman and E. Grosswald, "On Epstein's zeta function," Acta Arith., 9 (1964), 365-373.
N. N. Lebedev, Special Functions and their Applications, Prentice-Hall Inc., Englewood Cliffs, N. J. (1965).
Y. Motohashi, "A new proof of the limit formula of Kronecker," Proc. Japan. Acad., 44 (1968),614-616.
A. Selberg and S. Chowla, "On Epstein's zeta function," J. Reine Angew. Math., 227 (1967),86-110.
C. L. Siegel, Advanced Analytic Number Theory, Tata Institute of Fundamental Research, Bombay (1980).
J. R. Smart, "On the values of the Epstein zeta function," Glasgow Math. J., 14 (1973), 1-12.
P. R. Taylor, "The functional equation for Epstein's zeta function," Quart. J. Math. Oxford Ser., 11 (1940), 177-182.
E. C. Titchmarsh, The Theory of the Zeta-function, Clarendon Press, Oxford (1986).
I. J. Schwatt, An Introduction to the Operations with Series, Cheesea Publishing Company, New York (1961).