The Sound of Fractal Strings and the Riemann Hypothesis Michel L. LAPIDUS Institut des Hautes Etudes´ Scientifiques 35, route de Chartres 91440 – Bures-sur-Yvette (France) Juillet 2015 IHES/M/15/11 The Sound of Fractal Strings and the Riemann Hypothesis Michel L. Lapidus Abstract We give an overview of the intimate connections between natural direct and inverse spectral problems for fractal strings, on the one hand, and the Riemann zeta function and the Riemann hypothesis, on the other hand (in joint works of the author with Carl Pomerance and Helmut Maier, respectively). We also briefly dis- cuss closely related developments, including the theory of (fractal) complex dimen- sions (by the author and many of his collaborators, including especially Machiel van Frankenhuijsen), quantized number theory and the spectral operator (jointly with Hafedh Herichi), and some other works of the author (and several of his col- laborators). Key words: Riemann zeta function, Riemann hypothesis (RH), quantization, quan- tized number theory, fractal strings, geometry and spectra, direct and inverse spectral problems for fractal strings, Minkowski dimension, Minkowski measurability, com- plex dimensions, Weyl–Berry conjecture, fractal drums, infinitesimal shift, spec- tral operator, invertbility, quantized Dirichlet series and Euler product, universality, phase transitions, symmetric and asymmetric criteria for RH. Suggested short title for the paper: ”Fractal Strings and the Riemann Hypothesis.” University of California Department of Mathematics 900 University Avenue Riverside, CA 92521–0135, USA e-mail:
[email protected] 1 Contents The Sound of Fractal Strings and the Riemann Hypothesis............. 1 Michel L. Lapidus 1 Riemann Zeros and Spectra of Fractal Strings: An Informal Introduction .