Varilly-Alvarado, Anthony2023-01-032023-01-032022-122022-12-02December 2James, Austen A. "A Bayesian approach to computing Brauer groups of cubic surfaces." (2022) Diss., Rice University. <a href="https://hdl.handle.net/1911/114191">https://hdl.handle.net/1911/114191</a>.https://hdl.handle.net/1911/114191We present an algorithm for computing the Brauer groups of cubic surfaces. The algorithm takes as input an equation for a cubic surface X and a confidence threshold 0.5 < r < 1 and outputs a candidate for the Brauer group of X and a confidence level > r for the result. The algorithm runs by sampling lifts of Frobenius at many primes of good reduction and relies on Chebotarev’s density theorem and Bayesian inference to produce, with confidence level > r, a subgroup of the Weyl group of E_6. This subgroup represents the action of Galois on the geometric Picard group of X, from which we compute the Brauer group of X. We give a description of this algorithm and a proof that it terminates, as well as an implementation in Magma. We also examine the speed of such an approach relative to existing methods and explore how the Bayesian technique of this algorithm can be applied to answer questions concerning the Galois and Brauer groups of other classes of surfaces.application/pdfengCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.arithmetic geometrybrauer groupcubic surfacesdel pezzo surfacesalgebraic geometryrational pointsThesis2023-01-03