A POSSIBLE EXPLANATION FOR THE VALIDITY OF THE RIEMANN HYPOTHESIS Kevin Duffy To cite this version: Kevin Duffy. A POSSIBLE EXPLANATION FOR THE VALIDITY OF THE RIEMANN HYPOTHESIS. 2015. <hal-01170637> HAL Id: hal-01170637 https://hal.archives-ouvertes.fr/hal-01170637 Submitted on 2 Jul 2015 HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. A POSSIBLE EXPLANATION FOR THE VALIDITY OF THE RIEMANN HYPOTHESIS KEVIN JAN DUFFY Abstract. The renowned Riemann Hypothesis is considered from the perspective of symmetry in the functional equation for the Riemann zeta function developed by Bernhard Riemann. The validity of the Riemann Hypothesis is shown by considering the complex conjugations of the leading terms of this equation. 1. Introduction 1 where s = α + βi with α, β real ns and n a positive integer, and where ζ(s) is convergent for α > 1. The Riemann ζ(s) is defined as the series ζ(s) = P∞ n=1 zeta function is an analytical continuation of this series by Bernhard Riemann which is holomorphic for all s except at s = 1 [3]. Using a natural symmetry in the result Riemann [3, 2] obtained the functional equation: (1) sπ ζ(s) = ℵ(s)ζ(1 − s) = 2s π s−1 sin Γ(1 − s)ζ(1 − s) 2 R ∞ −z −s with Γ(1 − s) = 0 e z dz. The renowned Riemann Hypothesis (RH) is that non-trivial zeroes of the Riemann zeta function ζ(s) all have real part on the ’critical line’ Re(s) = α = 1 2 [1]-[4]. My explanation for the validity of RH will focus on the complex conjugations of this equation. Starting with ζ(s) = 0 and using the fact that ℵ(s) 6= 0 on the critical strip 0 < α < 1 where all non-trivial zeroes are known to occur [1]-[4] it is shown that ζ(s) = 0 ⇒ ℵ(s).ℵ(s) = 1 and why this is only possible if α = 0.5. 1991 Mathematics Subject Classification. AMS Subject Classification 11S40. Key words and phrases. Riemann zeta-function; functional equation. 1 2 KEVIN JAN DUFFY 2. Details Here I will define the complex functions resulting from (1) as: ζ(s) = u + vi, ζ(1 − s) = w + ti, ℵ(s) = x + yi (2) where u, v, w, t, x, y are all real. Thus, (3) (u + vi) = (x + yi)(w + ti) resulting in (4) x= uw + vt vw − ut 2 u2 + v 2 ,y = 2 , x + y2 = 2 >0 2 2 2 w +t w +t w + t2 Note in (4) x2 + y 2 6= 0 and exists on the critical strip 0 < α < 1 where all non-trivial zeroes are known to occur [1]-[4] because: 2s 6= 0, π s−1 6= 0, R ∞ −z −s e z dz 6= 0, and sin sπ 2 6= 0 for 0 < α < 1, and all of these are holomor0 phic for the same range, ⇒ ℵ(s) 6= 0 and is holomorphic for 0 < α < 1. Thus, using (1), ζ(s) = 0 ⇒ ζ(1 − s) = 0 ⇒ ζ(s) = ζ(1 − s) ⇒ u = w, v = t ⇒ x = 1, y = 0 ⇒ x2 + y 2 = 1 from (4). Thus the RH is true if ℵ(s).ℵ(s) = x2 + y 2 = 1 ⇐⇒ α = 0.5. (5) Theorem 1. ℵ(s).ℵ(s) = 1 ⇐⇒ α = 0.5 for 0 < α < 1 and β > 10. Proof. First, for ℵ(0.5 + βi)ℵ(0.5 + βi) using (1): (i) 2s π s−1 2s π s−1 = 20.5+βi π −0.5+βi 20.5−βi π −0.5−βi = βiπ βiπ sπ απ απ (ii) sin sπ 2 sin 2 = (sin 2 cos 2 +cos 2 sin 2 )(sin = 0.5(cos2 βπi 2 − sin2 βπi 2 ) 2 π βiπ απ απ 2 cos 2 −cos 2 at α = 0.5 = 0.5 cos (βπi) = 0.5 sin (βπi + π2 ) (iii) Γ(1 − s) = Γ(1 − s) = Γ(s) at α = 0.5 and so Γ(1 − s)Γ(1 − s) = Γ(s)Γ(1 − s) = π sin (βπi+ π 2) by Euler’s reflection formula. Thus, combining these equalities, ℵ(0.5 + βi).ℵ(0.5 + βi) = 1. sin βiπ 2 ) A POSSIBLE EXPLANATION FOR THE VALIDITY OF THE RIEMANN HYPOTHESIS 3 Second, consider ℵ(α+βi).ℵ(α + βi) in general on the critical strip 0 < α < 1 where all non-trivial zeroes are known to occur. To simplify some of what follows define functions f,g,h such that: (i) f = 2s π s−1 2s π s−1 = 4α π 2α−2 and 0 < 4a π 2a−2 < 4 for 0 < α < 1. βiπ βiπ βiπ sπ απ απ απ (ii) g = sin sπ 2 sin 2 = (sin 2 cos 2 + cos 2 sin 2 )(sin 2 cos 2 − βiπ cos απ 2 sin 2 ) 2 βiπ απ 2 βiπ 2 απ 2 cos 2 − cos 2 sin 2 ) 2 απ 2 βiπ 2 απ ' cos 2 (cos 2 + sin 2 ) for 0 < α < 1 and as for β large enough 2 βiπ cos2 βiπ 2 ' − sin 2 = cos2 βiπ which is constant on 0 < α < 1 for each β large enough. 2 sπ sπ Thus, sin 2 sin 2 ' constant for β large enough and 0 < α < 1. = (sin2 Even β > 10 suffices which is less than the first known zero of the zeta function (for the same reason this criteria will be used in what follows). Also, the value increasingly converges as β increases. (iii) h = Γ(1 − s)Γ(1 − s). Now ∂|ℵ(s)|2 ∂α (i) f 0 = 0 (ii) h = = f 0 gh + f g 0 h + f gh0 and using the partial derivatives: ∂(4α π 2α−2 ) = 2(2α+1) π (2α−2) (ln(π) ∂α ∂(Γ(1−s)Γ(1−s)) = ∂α + ln(2)) −(Ψ(1 − α − iβ) + Ψ(1 − α + iβ))Γ(1 − α + iβ)Γ(1 − α − iβ), where Ψ(s) = (iii) g 0 = ∂ sin Γ0 (s) Γ(s) sπ sπ 2 sin 2 ∂α = ( 12 )cos( π2 (α + iβ))πsin(( π2 (α − iβ)) + ( 21 )sin( π2 (α + iβ))cos( π2 (α − iβ))π = πcos( π2 α)cosh( π2 β)2 sin( π2 α) − πsin( π2 α)sinh( π2 β)2 cos( π2 α) = cos( π2 α)sin( π2 α)π and 0 < cos( π2 α)sin( π2 α)π < 1.6 for 0 < α < 1, then for 0 < α < 1 and β > 10, ∂|ℵ(s)|2 ∂α 0 = f gh( hh + 0 ' f gh( hh + f0 f ) g0 g + f0 f ) because cos2 0 < f gh( hh + βiπ 2 1.6 g + f0 f ) 0 ' f gh( hh + will be very large. 1.6 cos2 βiπ 2 + f0 f ) 4 KEVIN JAN DUFFY So, taking the overall partial derivative and simplifying gives (6) ∂|ℵ(s)|2 πβ < −4α π (2α−2) cosh2 Γ(1 − α + iβ)Γ(1 − α − iβ) ∂α 2 (Ψ(1 − α − iβ) + Ψ(1 − α + iβ) − 2ln(π) − 2ln(2)) The <((Ψ(α + iβ)) > 0 if β > 5/3 and α ≥ 0 (see [5] for details). Thus, <(Ψ(1 − α − iβ) + Ψ(1 − α + iβ)) > 0 on 0 < α < 1 and β > 5/3. Now (Ψ(1 − α − iβ) + Ψ(1 − α + iβ) − 2ln(π) − 2ln(2)) > 0 for β > 10 on 0 < α < 1 because the first two terms are then at least > 0.3676, the approximate absolute value of the last two terms. The term 4α π (2α−2) cosh2 πβ 2 is a very large positive real number for all 0 < α < 1 and β > 10. The remaining term Γ(1 − α + iβ)Γ(1 − α − iβ) is by definition a positive real number. From these points, and considering (6), we have ∂|ℵ(s)|2 ∂α < 0 and so |ℵ(s)|2 is strictly monotonic in terms of α on 0 < α < 1 for each β > 10. Now, as ℵ(α + βi).ℵ(α + βi) is strictly monotonic, this function can equal 1 at only a single unique value of α for each β > 10 on the critical strip 0 < α < 1. It is already shown above that this occurs at α = 0.5. Thus, ℵ(s).ℵ(s) = 1 =⇒ α = 0.5 for β > 10. 3. Summary In this simple way, as ζ(s) = 0 ⇒ ℵ(s).ℵ(s) = 1 and ℵ(s).ℵ(s) = 1 ⇐⇒ α = 0.5, the Riemann Hypothesis is shown to be true. If these results are correct then Riemann had already laid the foundation for the proof of his hypothesis by establishing the functional equation in his original paper [3]. Acknowledgments Obiora Collins is thanked for reading the manuscript many times, very fruitful discussions and valuable suggestions. Kian Duffy is thanked for pointing out the requirement that ℵ(s) 6= 0. A POSSIBLE EXPLANATION FOR THE VALIDITY OF THE RIEMANN HYPOTHESIS 5 References [1] E. Bombieri, Problems of the Millenium the Riemann Hypothesis. Clay Mathematics Institute (2000). http://www.claymath.org/sites/default/files/official problem description.pdf. Accessed January 2015. [2] H.M. Edwards, Riemann’s Zeta Function, Dover Publications, New York (1974). [3] B. Riemann, Ueber die Anzahl der Primzahlen unter einer gegebenen Grosse (On the Number of Prime Numbers less than a Given Quantity). Translated by D. R. Wilkins, (1998). [4] P. Sarnak P, Problems of the Millenium: the Riemann Hypothesis. Clay Mathematics Institute (2004). http://www.claymath.org/sites/default/files/sarnak rh 0.pdf. Accessed January 2015. [5] G.K. Srinavasan and P. Zvengrowski, On the horizontal monotonicity of |Γ(s)|, Can. Math. Bull., 54 (2011), 538–543. Institute of Systems Science, Durban University of Technology, Durban 4000, South Africa and School of Mathematics, Statistics and Computer Science, University of Kwazulu-Natal, Durban 4000, South Africa. E-mail address: kevind@dut.ac.za