Kadison Singer problem

Kadison Singer problem is a decade old question in mathematics that asks whether unique information can be obtained from a system in which only certain features can be measured or observed. For solving this question, posed in 1959, Indian mathematician Nikhil Srivatsava and two others were named the winners of the 2021 Michael and Sheila Held prize. In addition to this, the mathematician was also recognized for his solving the long standing question on Ramanujan graphs.