The Mirror at One-Half

 


Deep within the complex plane lies a hidden axis of symmetry where the secrets of the primes reside. Across the line

every point reflects into a twin, binding the zeta function in a perfect mathematical duality.

 

Welcome to another post where arithmetic, geometry and chaos meet.

In “The Riemann Hypothesis Revealed” I derive Euler’s Summation formula  

for real numbers  and  directly from the Euler-Maclaurin formula. The derivation emerges naturally from the theory of Bernoulli numbers and provides an illuminating bridge between discrete sums and continuous integrals. Take a look. I think you'll find it surprisingly enjoyable.

We can apply the formula for  positive integers and ,

because  and .

Now write

Thus,

Take  and make

But the left-hand side is

Therefore,

or

It can be shown (see Analytic Continuation of the Zeta function) that this representation is valid for . Furthermore, as explained at the end of Ramanujan’s Master Theorem, the quantity  arises naturally in the analytic continuation of the zeta function. In fact, one obtains the integral representation

This formula (see Analytic Continuation of the Zeta Function for details) leads to the identity

which is the celebrated functional equation of the Riemann zeta function. The functional equation implies that the nontrivial zeros are symmetric with respect to the critical line  . More precisely since , the nontrivial zeros are symmetric with respect to complex conjugation:

Combining the functional-equation symmetry  with complex conjunction gives the particularly useful symmetry

Indeed, for a zero  we have

Thus, a zero-free region near  has a mirror-image zero-free region near  with respect to the critical line  .

Restrict  to the rectangle . Since  has only finitely many zeros in this compact region, and none of them lie on the line  (see this post), the minimum distance from any zero to the line  is positive. Hence there exists a  such that the sub rectangle  contains no zeros of . Normally  depends on  and  as ; but we can obtain a positive lower bound of  for each value of .

Now consider the sum

Each term of  satisfies . As  grows, we choose  such that . For any ,  and for any positive constant  we have .

If  then . That is, . From the asymptotic formula for harmonic series, we know:  (see: Euler’s constant and an asymptotic formula for Harmonic series), hence

Additionally,

Indeed, we have

so

because

Thus, for sufficiently large ,

(apply the binomial expression: )

so

as claimed.

Moreover,

because for ,

and

so

Finally, it’s obvious that 

Putting everything together

Now take

That is,

Thus,

if we pick a constant  and sufficiently large  such that  .

Note: For two complex functions  we define

as , if there exist constants  and a neighborhood of  such that

for all  in that neighborhood (excluding possibly  itself).

Important nuance: if   we need to consider the direction. Behavior may differ depending on direction in  so typically we specify  uniformly in all directions unless stated otherwise. Of course, direction may be constrained if we work inside a sector or the half-plane. (See also this post)

Thus,  uniformly in the region that depends on :  and

 

For some absolute constant

if

(the number  is for convenience).

For any fixed constant  we can choose  sufficiently large so that

Consequently,

for , .

Take  for , and  has no zeros in  and .

■

One is naturally tempted to ask:

what if

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