Hylleraas was the son of Ole Andersen, a teacher in the mountain village of Engerdal, located in southern Norway.
Hylleraas started research on the double refraction of light after reading a book by Max Born regarding crystal lattices.
By 1926, the one-electron hydrogen had been solved, and Werner Heisenberg had formulated the two-electron helium problem quantum mechanically.
A simple first-order perturbation treatment still yielded considerably increased ionization potential for error with experimental measurement.
[citation needed] Hylleraas was one of the founding fathers of CERN and represented Norway at the European Council for Nuclear Research [3], which later led to the organization's establishment.