[3] He spent the following 15 years at Columbia University primarily pursuing research into proton structure and related topics.
Caldwell also takes a keen interested in probability, statistics and data analysis techniques and teaches these subjects at TUM.
[4] In his work, Caldwell is primarily concerned with the development of new particle accelerator technologies based on plasma keel fields[clarify] and with the investigation of quarks and gluons and their interactions.
In addition, there is research into the fundamental properties of neutrinos and the search for new dark matter candidates – the axions.
He is involved in the following research projects: Acceleration of electrons in the plasma wakefield of a proton bunch; AWAKE Collaboration (E. Adli (Oslo U.)
C78 (2018) no.9, 793 Global Bayesian analysis of neutrino mass data; Allen Caldwell, Alexander Merle, Oliver Schulz, Maximilian Totzauer (Munich, Max Planck Inst.).
D96 (2017) no.7, 073001 Dielectric Haloscopes: A New Way to Detect Axion Dark Matter; MADMAX Working Group (Allen Caldwell (Munich, Max Planck Inst.)