Neutron Stars in Screened Modified Gravity: Chameleon vs Dilaton
  We consider the scalar field profile around relativistic compact objects such
as neutron stars for a range of modified gravity models with screening
mechanisms of the chameleon and Damour-Polyakov types. We focus primarily on
inverse power law chameleons and the environmentally dependent dilaton as
examples of both mechanisms. We discuss the modified Tolman-Oppenheimer-Volkoff
equation and then implement a relaxation algorithm to solve for the scalar
profiles numerically. We find that chameleons and dilatons behave in a similar
manner and that there is a large degeneracy between the modified gravity
parameters and the neutron star equation of state. This is exemplified by the
modifications to the mass-radius relationship for a variety of model
parameters.
