December 2020 All Complex Zeros of the Riemann Zeta Function Are on the Critical Line: Two Proofs of the Riemann Hypothesis (°) Roberto Violi (*) Dedicated to the Riemann Hypothesis on the Occasion of its 160th Birthday (°) Keywords: Riemann Hypothesis; Riemann Zeta-Function; Dirichlet Eta-Function; Critical Strip; Zeta Zeros; Prime Number Theorem; Millennium Problems; Dirichlet Series; Generalized Riemann Hypothesis. Mathematics Subject Classification (2010): 11M26, 11M41. (*) Banca d’Italia, Financial Markets and Payment System Department, Rome, via Nazionale 91, Italy. E-Mail:
[email protected]. The opinions of this article are those of the author and do not reflect in any way the views or policies of the Banca d’Italia or the Eurosystem of Central Banks. All errors are mine. Abstract In this study I present two independent proofs of the Riemann Hypothesis considered by many the greatest unsolved problem in mathematics. I find that the admissible domain of complex zeros of the Riemann Zeta-Function is the critical line given by 1 ℜ(s) = . The methods and results of this paper are based on well-known theorems 2 on the number of zeros for complex-valued functions (Jensen’s, Titchmarsh’s and Rouché’s theorem), with the Riemann Mapping Theorem acting as a bridge between the Unit Disk on the complex plane and the critical strip. By primarily relying on well- known theorems of complex analysis our approach makes this paper accessible to a relatively wide audience permitting a fast check of its validity. Both proofs do not use any functional equation of the Riemann Zeta-Function, except leveraging its implied symmetry for non-trivial zeros on the critical strip.