Raphael S. Steiner



Automorphic Forms

I am interested in questions relating to arithmetic quantum chaos, such as (moments of) $L^p$-norms and other objects relating to automorphic forms, such as $L$-functions and Kloosterman sums.

Number Theory

Whilst my research is centered around automorphic forms, I have a further interest in sieves and a soft spot for elementary number theory.


Whether work, data, computation flows, or simply numbers, I take joy in modelling and optimising, in particular getting to that sweet optimum.

About me

I am currently a research engineer at the Computing Systems Lab at the Huawei Research Center in Zürich. I am working on aspects of high performance computing, such as (a)synchronous dataflows, shared and distributed memory systems, and distributed algorithms.

Prior to my current employement, I had the pleasure of being a Hermann-Weyl-Instructor at ETH in Zurich and a member at the Institute for Advanced Study in Princeton. There I conducted research in analytic number theory, in particular, the theory of automorphic forms. I have received my Ph.D. from the University of Bristol under the joint supervision by Tim Browning and Andrew Booker.

Before university I participated in the Swiss Math Olympiad, where I’ve won a complete set of medals over the three years I participated. I further qualified for the International Math Olympiad, where I won a bronze medal in my last year. After participating I joined the organisation team of the Swiss Math Olympiad, where I was quite active until recently. Over the years some of my problems made it into different exams and you can find a nice selection thereof in the Olympiad section.

Raphael S. Steiner

Selected Publications

Theta functions, fourth moments of eigenforms, and the sup-norm problem II

joint with Ilya Khayutin and Paul D. Nelson.

Twisted Linnik implies optimal covering exponent for $S^3$

joint with Tim Browning and V. Vinay Kumaraswamy.

Small diameters and generators for arithmetic lattices in $\mathrm{SL}_2(\mathbb{R})$ and certain Ramanujan graphs

Curriculum vitae

  • 2023-

    Research Engineer

    At the Computing Systems Lab, Huawei Research Center, Zürich, CH.

  • 2020-2023

    Hermann Weyl Instructor

    Postdoctoral Researcher at ETH, Zürich, CH.

  • 2018-2020

    Postdoctoral Researcher

    Member at the Institute for Advanced Study, Princeton NJ, USA.

  • 2014-2018

    Ph.D. Researcher

    Under the supervision of Tim Browning and Andrew Booker at the University of Bristol, Bristol, UK. Ph.D. thesis.

  • 2012-2014

    Master of Science

    In Mathematics at ETH, Zürich, CH. Master thesis written under the supervision of Abhishek Saha and Emmanuel Kowalski.

  • 2012-2014

    Bachelor of Science

    With Distinction in Mathematics at ETH, Zürich, CH. Bachelor thesis written under the supervision of Clemens Fuchs.

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