Raj Kumar Pathria, an Indian–American physicist and Urdu poet, died on January 7, 2026, at the age of 92.
He was a Distinguished Professor Emeritus at the University of Waterloo and was known for his work on statistical mechanics, including studies of superfluidity in liquid helium, Lorentz transformation of thermodynamic quantities, exact evaluation of lattice sums, and finite-size effects in phase transitions. Pathria authored a graduate textbook on statistical mechanics, whose fourth edition appeared in 2021, and wrote a book on relativity published as a Dover edition in 2003.
Raj Kumar Pathria (March 30, 1933 – January 7, 2026) was an Indian theoretical physicist, a Distinguished Professor Emeritus at University of Waterloo, and an Urdu poet.