Mass Screening in Modified Gravity

Understand

Models of modified gravity introduce extra degrees of freedom, which for consistency with the data, should be suppressed at observable scales.

• In the models that share properties of massive gravity such a suppression is due to nonlinear interactions: An isolated massive astrophysical object creates a halo of a nonzero curvature around it, shielding its vicinity from the influence of the extra degrees of freedom.
• We emphasize that the very same halo leads to a screening of the gravitational mass of the object, as seen by an observer beyond the halo.
• We discuss the case when the screening could be very significant and may rule out, or render the models observationally interesting.