Vainshtein Solutions Without Superluminal Modes

Understand

The Vainshtein mechanism suppresses the fifth force at astrophysical distances, while enabling it to compete with gravity at cosmological scales.

• Typically, Vainshtein solutions exhibit superluminal perturbations.
• However, a restricted class of solutions with special boundary conditions were shown to be devoid of the faster-than-light modes.
• Here we extend this class by finding solutions in a theory of quasidilaton, amended by derivative terms consistent with its symmetries.