of which prestigious award are terence tao,wendelin werner,andrei okounkov and grigori perelman (declined) the

Question

the recipients in 2006?

Answer 1

Perelman refused the Fields Medal of the 2006 International Congress of the International Mathematical Union.

Answer 2

The Fields Medal is a prize awarded to two, three, or four mathematicians not over forty years of age at each International Congress of the International Mathematical Union, a meeting that takes place once every four years.
Founded at the behest of Canadian mathematician John Charles Fields, the medal was first awarded in 1936 and has been regularly awarded since 1950. Its purpose is to give recognition and support to younger mathematical researchers who have already made major contributions.In 1966, Alexander Grothendieck boycotted his own Fields Medal ceremony, held in Moscow, to protest Soviet military actions taking place in Eastern Europe.
In 1970, Sergei Petrovich Novikov, due to restrictions placed on him by the Soviet government, was unable to travel to the congress in Nice to receive his medal.
In 1978, Gregori Margulis, due to restrictions placed on him by the Soviet government, was unable to travel to the congress in Helsinki to receive his medal.
In 2006, Grigori Perelman, credited with proving the Poincaré conjecture, refused his Fields Medal and did not attend the congress.