Hans Frederick Blichfeldt
Hans Frederick Blichfeldt was a Danish and American mathematician who worked on group theory and the geometry of numbers. He introduced Blichfeldt's principle and Blichfeldt's upper bound on the density of sphere packings. He graduated from Stanford University in 1896 and got his Ph.D. from Leipzig University in 1898. He returned to Stanford and remained there until his death. He was executive head of the Mathematics Department from 1927 until 1938.
