Neutrino mass and kinetic gravity braiding degeneracies
  Modified theories of gravity yield an effective dark energy in the background
dynamics that achieves an accelerated expansion of the universe. In addition,
they present a fifth force that induces gravitational signatures in structure
formation, and therefore in the matter power spectrum and related statistics.
On the other hand, massive neutrinos suppress the power spectrum at scales that
also modified gravity enhances it, so a degeneration of these effects has been
recognized for some gravity models. In the present work, we study both effects
using kinetic gravity braiding (nKGB) models to find that in spite of some
degeneracies, the role of the fifth force at very large scales imprints a bump
in the matter power spectrum as a distinctive signature of this model and,
therefore, acts as a smoking gun that seems difficult to match within the
present knowledge of power spectra. These models result interesting, however,
since the n=1 presents no H0 tension, and all nKGB studied here present no
sigma8 tension and, in addition, a null neutrino mass is excluded.
