Thomas Hakon Grönwall or Thomas Hakon Gronwall (born Hakon Tomi Grönwall;[1] January 16, 1877 in Dylta bruk, Sweden – May 9, 1932 in New York City, New York) was a Swedish mathematician.
Grönwall worked for about a year as a civil engineer in Germany before he emigrated to the United States in 1904.
In 1925 he started to collaborate with Victor LaMer, which led to his joining the Department of Physics at Columbia University as an associate in 1927[citation needed].
There were no teaching obligations; he had complete control of his own time and an abundance of new intriguing problems to address in physical chemistry and in atomic physics[citation needed].
He developed an analytical solution to the Poisson-Boltzmann equation as it appears in the Debye–Hückel theory[1]