Ian Ochs uses theoretical analysis and computation to study problems in plasma physics relevant to nuclear fusion energy and astrophysics. This research is particularly focused on how energy and momentum can flow between different parts of the plasma. This focus has motivated his work in several areas of research, including the transfer of momentum between fields and matter during wave-particle interactions; the transport of energy due to synchrotron emission and absorption in high-temperature fusion and astrophysical plasmas; the interplay of collisions and radiation in determining loss rates from magnetic mirrors; and the flow of energy in aneutronic proton-Boron 11 fusion plasmas.