Beating non-linearities: improving the Baryon Acoustic Oscillations with
  the linear point
  We propose a new way of looking at the Baryon Acoustic Oscillations in the
Large Scale Structure clustering correlation function. We identify a scale s_LP
that has two fundamental features: its position is insensitive to non-linear
gravity, redshift space distortions, and scale-dependent bias at the 0.5%
level; it is geometrical, i.e. independent of the power spectrum of the
primordial density fluctuation parameters. These two properties together make
s_LP, called the "linear point", an excellent cosmological standard ruler. The
linear point is also appealing because it is easily identified irrespectively
of how non-linearities distort the correlation function. Finally, the
correlation function amplitude at s_LP is similarly insensitive to non-linear
corrections to within a few percent. Hence, exploiting the particular Baryon
features in the correlation function, we propose three new estimators for
growth measurements. A preliminary analysis of s_LP in current data is
encouraging.
