Caucher Birkar proves in a 2016 preprint, published in its final form in Annals of Mathematics in 2019, the boundedness of log canonical Fano varieties with standard coefficients, a central result in the minimal model program in algebraic geometry that generalizes to arbitrary dimension earlier results known only in particular cases. Birkar, of Kurdish ethnic origin and born in the Kurdish region of Iran, sought political asylum in the United Kingdom in the late 1990s, completing his entire subsequent mathematical career at Cambridge after arriving in the country as a refugee. He received the Fields Medal in 2018; his original medal was stolen from his briefcase during the award ceremony itself in Rio de Janeiro, and the International Mathematical Union subsequently gave him a replacement medal.