Who is Jacob Tsimerman: Fields Medal-winning mathematics professor who was once one of AI's biggest critics, now joining OpenAI to tackle AI safety

Jacob Tsimerman is widely regarded as one of the world's leading mathematicians, earning the prestigious Fields Medal in 2026 for his groundbreaking contributions to number theory . Yet, shortly after receiving mathematics' highest honour, the Canadian professor made headlines for an unexpected career move. Despite previously warning about the potential dangers posed by advanced artificial intelligence , Tsimerman announced that he would join OpenAI to focus on AI safety research. His decision reflects a growing belief among many scientists that the best way to address the risks of powerful AI systems is to work directly on making them safer, more reliable and better aligned with human interests.