Constructive Approximation

, Volume 4, Issue 1, pp 175–198

Moment inequalities and the Riemann hypothesis

  • George Csordas
  • Richard S. Varga

DOI: 10.1007/BF02075457

Cite this article as:
Csordas, G. & Varga, R.S. Constr. Approx (1988) 4: 175. doi:10.1007/BF02075457


It is known that the Riemann hypothesis is equivalent to the statement that all zeros of the Riemann ξ-function are real. On writingξ(x/2)=8 ∫0 Φ(t) cos(xt)dt, it is known that a necessary condition that the Riemann hypothesis be valid is that the moments\(\hat b_m (\lambda ): = \int_0^\infty {t^{2m} e^{\lambda t^2 } \Phi (t)dt}\) satisfy the Turán inequalities
$$(\hat b_m (\lambda ))^2 > \left( {\frac{{2m - 1}}{{2m + 1}}} \right)\hat b_{m - 1} (\lambda )\hat b_{m + 1} (\lambda )(m \geqslant 1,\lambda \geqslant 0).$$
We give here a constructive proof that log\(\Phi (\sqrt t )\) is strictly concave for 0 <t < ∞, and with this we deduce in Theorem 2.4 a general class of moment inequalities which, as a special case, establishes that the inequalities (*) are in fact valid for all real λ. As the case λ=0 of (*) corresponds to the Pólya conjecture of 1927, this gives a new proof of the Pólya conjecture.

AMS classification

Primary 30D10 Primary 30D15 Secondary 26A51 Key words and phrases Riemann hypothesis Turán inequalities Universal factors Logarithmic concavity Moments 

Copyright information

© Springer-Verlag New York Inc. 1988

Authors and Affiliations

  • George Csordas
    • 1
  • Richard S. Varga
    • 2
  1. 1.Department of MathematicsUniversity of Hawaii at ManoaHonoluluUSA
  2. 2.Institute for Computational MathematicsKent State UniversityKentUSA

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