Shayan Oveis Gharan

Shayan Oveis Gharan is awarded the IMU Abacus Medal 2026 for his landmark contributions to the theory of algorithms, taking the analysis of algorithms beyond combinatorics and probabilistic analysis into the theory of the geometry of polynomials and related topics. This theory has led to deeper understanding of distributions on spanning trees and matroid bases in general. Oveis Gharan’s work improved the approximation of the metric travelling salesperson problem, breaking the limit on the approximation factor in Christofides’ 3/2-algorithm from 50 years ago, and led to a revolution in the understanding of Markov Chain Monte Carlo sampling algorithms (proving the Mihail-Vazirani conjecture and giving a self-contained proof that resolved the strongest version of Mason's conjecture) through spectral independence.