Some Extended Zeta Functions Provide Easy

Proofs of Riemann's Hypothesis

This page is now subject to the author's counterexample at http://www.coolissues.com/mathematics/Riemann/disproof.htm

James Constant

math@coolissues.com

While extended zeta functions support investigations of Riemann's hypothesis and estimates for the Prime Number Theorem, some zeta functions offer better prospects for providing easy proofs.

Definitions

A first zeta function is defined by

.................... oo
(1) ...... z(s)= ....................................s=x+jy........ x>1
................... n=1

A second zeta function is defined by

....................... oo
(2) ......z(1-s)= ...............................s=x+jy........ x<0
...................... n=1

In 1859, Riemann had the idea to define z(s) for all complex numbers s by analytic extension. This extension is important in number theory and plays a central role in the distribution of prime numbers.

There are a number of ways of extending the zeta function to points where 0<x1.1 One way of extending is by using the first f function alternating series defined by2

.................... oo
(3) ...... f(s)= ............................ s=x+jy ........ x>0
................... n=1

which provides an extension of the first zeta function (1) to values of z such that 0<x1 by means of the formula

(4) ...... f(s)=(1-2)z(s) ....................... x>1

A second f function is defined by

....................... oo
(5) ...... f(1-s)= ......................... s=x+jy ........ x<1
...................... n=1

which provides an extension of the second zeta function (2) to values of z such that 0<x1 by means of the formula

(6) ...... f(1-s)=(1-2)z(1-s) .................... x<0

Equations (1) through (6) are analytic.

Riemann's Extended Zeta Function and Functional Equation

Euler (1737) noted that the formula

(7) ......

for integers s>1 connected integers and primes, the sum extending to all positive integers n, and the product to all positive primes p. Considering as a function of z(s) of the complexvariable s, Riemann (1859) examined this equation for s as a complex number and found that it can be extended to points with real part s1 by the formula (among others)3

(8) ...... z(s)=

which function is another form of an extended Riemann zeta function.

Riemann also proved that his extended zeta function (8) satisfies a functional equation (among others)

(9) ...... z(s) = z(1-s) ........ s=x+jy

which led him to the theorem that all the zeros of z(s), except those at s=-2,-4,-6, . . . , lie in the critical strip of the s-plane for which where x is the real part of s. Riemann conjectured that all the zeroes in the critical strip should lie on the critical line x=1/2.4 Attempts to prove or disprove this conjecture have generated a vast and intricate department of analysis, especially since Hardy (1914) proved that z(s) has an infinity of zeros on x=1/2.5 The question is still open in 2001. A prize is available to prove or disprove Riemann's hypothesis.6

Riemann's extended zeta function (8) is probably one reason it has proven difficult to investigate Riemann's hypothesis. While the function is analytic, it is difficult to express it as a complex number with real and imaginary parts. This is not the case for the extended zeta or f function of equation (3). I will now show how equation (3) is a better extended zeta function for investigating Riemann's hypothesis. I note that Riemann's functional equation (9) can be expressed as the ratio z(s)/z(1-s)=C(s) and that, but for some function B(s), z(s)/z(1-s)= B(s)f(s)/f(1-s) which can now be used in equation (9) to produce a new functional equation

(10) ...... f(s)=A(s)f(1-s)

the importance of which is that the f-functions can be easily expressed as complex numbers with real and imaginary parts. Elsewhere, I attempt a proof of Riemann's hypothesis using Riemann's extended zeta function (8).7, Here, I use extended zeta function (3) to make the proof.

Proving Riemann's Hypothesis

My theory for proving Riemann's hypothesis is simple. Since, f(s)f(1-s), except when x=1/2, functional equation (10) precludes zeros in the critical strip, except when x=1/2. I now show that f(s)=f(1-s)=0 only on the critical line x=1/2.

It has already been shown that all zeros are in the critical strip and that they are symmetric about the critical line x=1/2.8 Riemann's functional equation (9) can be restated in terms of the new functional equation (10) in which A(s)0 at all points on the critical strip. Since functions f(s) and f(1-s) are single valued at each point on the critical strip they can be written in terms of their real and imaginary parts f(s)=u+jv and f(1-s)=u'+jv' in which

.................. oo .............................................. oo
(11) ...... u= ................v=-
................. n=1 ............................................ n=1

.................. oo ............................................. oo
..............u'= ................v'=
................. n=1 ........................................... n=1

When sin(ylnn)=0, equations (11) reduce to

.................. oo
(12) ...... u= ................v=0
................. n=1

.................. oo
..............u'= .............. v'=0
................. n=1

which occur when

(13) yn,k=, .....n=1,2,3,...., .....k=0,1,2,3,....., sin(yn,klnn)=0, ......cos(yn,klnn)=(-1)k

The significance of result (13) is that it gives, for each n, the (infinite) values of y for which v=v'=0 and thus greatly simplifies extended zeta f functions (3) and (5). It remains to be shown that equations (12) put the zeros of u and u' exactly on the critical line x=1/2. These equations now become

.......................... oo
(14) ...... u=(-1)k (-1)n+1
......................... n=1

.......................... oo
.............
u'=(-1)k
..........................
n=1

Equations (14) are conditionally convergent infinite series which, depending from the rearrangement of terms, can be divergent or convergent to some number including zero. In such series, the value of the sum of the series can be changed at will by suitable rearraingement of the series.9 Non-zero values of each series occur in the critical strip 0<x<1 even when x=1/2. Zero values mean that the value of each series, in the limit, approaches zero uà0 and u'à0. Since the difference between the sum of a converging alternating series and the sum of the first n terms is numerically less than the (n+1)th term < and < . Thus, as nàoo and uàu'à0, xà1-x and xà1/2 which proves Riemann's hypothesis in the sense that, in the limit, zeros of f(s)=f(1-s) approach but never reach the critical line x=1/2.

A more rigorous proof puts zeros exactly on the critical line x=1/2 and nowhere else. Formally, since A(s) in functional equation (10) is determinate at all points of the critical strip including when x=1/2, f(s) and f(1-s) are different functions at all points of the critical strip except when x=1/2 and sin(ylnn)=0 for which f(s)=f(1-s)=0. This proves Riemann's hypothesis in the sense that zeros exist only on the critical line x=1/2. For example, if zeros exist on either side of and on x=1/2, then A(s)=f(s)/f(1-s)=0/0 and, thus, A(s) is indeterminate at all points of the critical strip including when x=1/2, a result precluded by determinate A(s) in equation (10). Note that, since sin(ylnn)=0, y is not a single point but a collection of double infinite numbers yn,k on the critical line. In summary:

1. Equation (10) dictates that f(s)=f(1-s) on the critical line;
2. Equation f(s)-f(1-s)=0 dictates that sin(ylnn)=0 on the critical line; and
3. Equations (11) through (14) dictate that f(s)=f(1-s)=0 on the critical line,

thus proving Riemann's hypothesis.

The Prime Number Theorem and Riemann's Hypothesis

The prime number theorem states that the number of primes p(x) in an interval x is approximately p(x)~x/lnx where lnx is the natural logarithm of x. This theorem was proved by Hadamard (1896) and independently by de la Valle Pousson (1896) using Riemann's hypothesis, after showing that the zeros of Riemann's zeta function z(s) cannot lie too far off the critical line. Also assuming that the Riemann hypothesis is true, von Koch (1901) proved that

.................................................................................oo
(15) ...... p(x)=Li(x)+O(x2logx) ................... Li(x)=
................................................................................
2

where L(i) is Gauss's integral and O(x2logx) is an error term.10

Thus, if Riemann's hypothesis is true, equation (15) tells us that Li(x) is a very good approximation to p(x). The known values of p(x) today agree with equation (15) but it is admitted that it is not easy to "have an idea of what should be exactly the error term." 11. Here, results (13) and (14) should be helpful.


1 See E.C. Titchmarsh, The theory of the Riemann Zeta-function, Oxford Science Publications, second edition, revised by D.R.Heath-Brown (1986).

2 See R. Courant, Differential and Integral Calculus, Interscience Publishers, Inc. New York 1947 Vol. II page 568 problem 13.

3 See "The Rieman Hypothesis in a Nutshell" at http://www.math.ubc.ca/~pugh/RiemannZeta/RiemannZetaLong.html

4 See Chris Caldwell's "The Riemann Hypothesis" (University of Tennessee at Martin) at http://www.utm.edu/research/primes/notes/rh.html

5 See E.T. Bell, The Development of Mathematics, Dover Publications, New York 1972. Page 315.

6 See Enrice Bombieri's "The Riemann Hypothesis" (Clay Mathematics Institute) at http://www.claymath.org/prize_problems/riemann.htm

7 See my Proof of Riemann's Hypothesis at http://riemann.coolissues.com/rieman.htm

8 See endnote 4 above.

9 See R. Courant, Differential and Integral Calculus, Interscience Publishers, Inc. New York, 1947 2d ed. Vol. I pages 372-375.

10 See pages 5-7 in Chris Caldwell's "How Many Primes Are There" at http://www.utm.edu/research/primes/howmany/shtml

11 See "The Riemann's Zeta Function z(s)" at http://numbers.computation.free.fr/Constant/Primes/counting/Primes.html

Copyright by James Constant 2003

By the same author: http://www.coolissues.com/mathematics/sameauthor.htm