The Institute of Theoretical Physics ("Institut de physique théorique") (IPhT) is a research institute of the Direction of Fundamental Research (DRF) of the French Alternative Energies and Atomic Energy Commission (CEA). The Institute is also a joint research unit of the Institute of Physics (INP), a subsidiary of the French National Center for Scientific Research (CNRS). It is associated to the Paris-Saclay University. IPhT is situated on the Saclay Plateau South of Paris.