One reason was that many of his results, for instance the extension of Holmgren's uniqueness theorem, the analysis of the Schrödinger operator, and the existence theorem for Boltzmann 's equation, were two decades ahead of their time and therefore not immediately appreciated.
Isang dahilan ay na marami sa kanyang resulta, halimbawa ang extension ng Holmgren's uniqueness teorama, ang pagtatasa ng Schrödinger operator, at ang pagkakaroon teorama para sa Boltzmann 's equation, ay dalawang dekada ahead ng kanilang mga oras at sa gayon ay hindi agad-agad na pahalagahan.