Theory HEP Seminar

Can we have a healthy violation of the NEC?

Francis Duplessis

Arizona State University

I will be discussing some recent attempts to violate the null energy condition (NEC) in a class of models called Kinetic Gravity Braiding (KGB). A survey of the different instability and properties that one must avoid will be given. Afterwards I will elaborate on how external matter can play an important role in the stability and phenomenology of these models. This will be shown in an explicit example dubbed "Subluminal Galilean Genesis". From these constraints, one might ponder on the possibility of nicely constraining the parameter space of KGB models that can violate the NEC in a healthy fashion.