Yakov Borisovich Zeldovich ForMemRS (Russian: Я́ков Бори́сович Зельдо́вич, Belarusian : Я́каў Бары́савіч Зяльдо́віч ; 8 March 1914 – 2 December 1987), also known as YaB, D.N. was a leading Soviet physicist of Belarusian origin, who is known for his prolific contributions in physical cosmology, physics of thermonuclear reactions, combustion, and hydrodynamical phenomena.