The Man Who Knew Infinity Dev Patel Srinivasa Ramanujan.

Following Benedict Cumberbatch’s tour-de-force performance as Alan Turing in The Imitation Game and and Eddie Redmayne’s even more dazzling turn as Stephen Hawking in The Theory of Everything, Dev Patel is the latest British actor to pull out the stops as a troubled genius in handsome period biopic The Man Who Knew Infinity.

Self-taught Indian mathematician Srinivasa Ramanujan, the character Patel plays, is not nearly so well known as Turing or Hawking, but as writer-director Matthew Brown’s film reveals, his tale is every bit as remarkable as theirs.

The Man Who Knew Infinity views Ramanujan’s story through the prism of his friendship with Cambridge don GH Hardy (Jeremy Irons), the man who invited him to England in 1913 and, in the teeth of prejudice, became his ardent champion. ‘Just as Mozart would hear an entire symphony in his head,’ he tells his protégé, ‘you dance with numbers to infinity.’

The Man Who Knew Infinity Jeremy Irons G.H. Hardy Dev Patel Srinivasa Ramanujan.

Initially scorned, Ramanujan’s groundbreaking work in number theory would revolutionise mathematics, although his ideas would only be fully appreciated years after his tragically early death at the age of 32 in 1920.

Brown’s telling of Ramanujan’s story is, to be honest, a little by the numbers, with much of the drama hinging on the contrasts between Patel’s intuitive Ramanujan and Irons’s rigorously methodical Hardy. One is an untutored shipping clerk from Madras separated by 6,000 miles from his young bride (Devika Bhise), the other a crusty bachelor married to mathematics; one believes an equation has no meaning unless it expresses ‘a thought of god’, the other is an atheist who doesn’t believe in anything he can’t prove.

Yet even if the movie is fairly formulaic, Patel’s sympathetic performance keeps us engaged and he gets strong support from the likes of Toby Jones, Jeremy Northam, Stephen Fry, and above all co-star Irons, who delivers a masterclass in cranky eccentricity and buttoned-up reserve.

Certificate 12. Runtime 109 mins. Director Matthew Brown

The Man Who Knew Infinity debuts on Sky Cinema Premiere on Sunday 29 January and is available on Blu-ray & DVD from Warner Home Video.