Maxim Kontsevich proves in 1992, in Communications in Mathematical Physics, the conjecture formulated by Edward Witten concerning intersection theory on the moduli spaces of algebraic curves, relating it to a matrix model coming from theoretical physics (two-dimensional quantum gravity). The result rigorously connects a purely algebraic-geometry problem with physical predictions Witten had derived heuristically, and would be reproved years later using a completely different geometric approach by Maryam Mirzakhani (Fields Medal 2014), as well as, independently, by Okounkov and Pandharipande. Kontsevich received the Fields Medal in 1998.