Absence of solid angle deficit singularities in beyond-generalized Proca
  theories
  In Gleyzes-Langlois-Piazza-Vernizzi (GLPV) scalar-tensor theories, which are
outside the domain of second-order Horndeski theories, it is known that there
exists a solid angle deficit singularity in the case where the parameter
$\alpha_{\rm H}$ characterizing the deviation from Horndeski theories
approaches a non-vanishing constant at the center of a spherically symmetric
body. Meanwhile, it was recently shown that second-order generalized Proca
theories with a massive vector field $A^{\mu}$ can be consistently extended to
beyond-generalized Proca theories, which recover shift-symmetric GLPV theories
in the scalar limit $A^{\mu} \to \nabla^{\mu} \chi$. In beyond-generalized
Proca theories up to quartic-order Lagrangians, we show that solid angle
deficit singularities are generally absent due to the existence of a temporal
vector component. We also derive the vector-field profiles around a compact
object and show that the success of the Vainshtein mechanism operated by vector
Galileons is not prevented by new interactions in beyond generalized Proca
theories.
