Tosio Kato aworked in the field of mathematics where he became known for "Kato's conjecture", a mathematical problem posed in 1953 and finally solved in 2001.
Kato's conjecture
HeinzKato inequality
Kato Rellich Theorem Many works of Kato are related to mathematical physics. Kato initially posed the problem in 1953. The problem remained unresolved for nearly a half-century, until it was jointly solved in 2001 by Pascal Auscher, Steve Hofmann, Michael Lacey, Alan McIntosh, and Philippe Tchamitchian. 
