Amal Kumar Raychaudhuri (14 September 1923 - 18 June 2005) was an Indian physicist, known for his research in general relativity and cosmology. His most significant contribution is the eponymous Raychaudhuri equation, which demonstrates that singularities arise inevitably in general relativity and is a key ingredient in the proofs of the Penrose–Hawking singularity theorems. Raychaudhuri was also revered as a teacher during his tenure at Presidency College, Kolkata. Many of his students have gone on to become established scientists. Amal Kumar Raychaudhuri described the dynamics of light’s motion through the curved parts of spacetime. It was “perhaps the single most important input” for one of Hawking’s major findings.