Hurwitz Zeta Function - Rational Values

Rational Values

The Hurwitz zeta function occurs in a number of striking identities at rational values. In particular, values in terms of the Euler polynomials :

E_{2n-1}\left(\frac{p}{q}\right) =
(-1)^n \frac{4(2n-1)!}{(2\pi q)^{2n}}
\sum_{k=1}^q \zeta\left(2n,\frac{2k-1}{2q}\right)
\cos \frac{(2k-1)\pi p}{q}

and

E_{2n}\left(\frac{p}{q}\right) =
(-1)^n \frac{4(2n)!}{(2\pi q)^{2n+1}}
\sum_{k=1}^q \zeta\left(2n+1,\frac{2k-1}{2q}\right)
\sin \frac{(2k-1)\pi p}{q}

One also has

\zeta\left(s,\frac{2p-1}{2q}\right) =
2(2q)^{s-1} \sum_{k=1}^q \left[
C_s\left(\frac{k}{q}\right) \cos \left(\frac{(2p-1)\pi k}{q}\right) +
S_s\left(\frac{k}{q}\right) \sin \left(\frac{(2p-1)\pi k}{q}\right)
\right]

which holds for . Here, the and are defined by means of the Legendre chi function as

and

For integer values of ν, these may be expressed in terms of the Euler polynomials. These relations may be derived by employing the functional equation together with Hurwitz's formula, given above.

Read more about this topic:  Hurwitz Zeta Function

Famous quotes containing the words rational and/or values:

    “[I]n Great-Britain it is said that their constitution relies on the house of commons for honesty, and the lords for wisdom; which would be a rational reliance if honesty were to be bought with money, and if wisdom were hereditary.”
    —Thomas Jefferson (1743–1826)

    “If the Russians have gone too far in subjecting the child and his peer group to conformity to a single set of values imposed by the adult society, perhaps we have reached the point of diminishing returns in allowing excessive autonomy and in failing to utilize the constructive potential of the peer group in developing social responsibility and consideration for others.”
    —Urie Bronfenbrenner (b. 1917)