<human>:  In the book, ‘The Man Who Knew Infinity’, what is the name of the character who is the main protagonist?
<bot>: The main protagonist is the mathematician Srinivasa Ramanujan. His story is very interesting! Ramanujan was born in 1887 in India, and he was a brilliant mathematician. He was self-taught and taught himself mathematics, but he had to go to England to get his Ph.D. because there was no university in India that offered a Ph.D. program in mathematics. After getting his Ph.D., he went back to India and taught at the University of Madras.