Cosmological Leverage from the Matter Power Spectrum in the Presence of
  Baryon and Nonlinear Effects
  We investigate how the use of higher wavenumbers (smaller scales) in the
galaxy clustering power spectrum influences cosmological constraints. We take
into account uncertainties from nonlinear density fluctuations, (scale
dependent) galaxy bias, and baryonic effects. Allowing for substantially model
independent uncertainties through separate fit parameters in each wavenumber
bin that also allow for the redshift evolution, we quantify strong gains in
dark energy and neutrino mass leverage with increasing maximum wavenumber,
despite marginalizing over numerous (up to 125) extra fit parameters. The
leverage is due to not only an increased number of modes but, more
significantly, breaking of degeneracies beyond the linear regime.
