Dark Energy Survey Year 3 Results: Three-Point Shear Correlations and
  Mass Aperture Moments
  We present high signal-to-noise measurements of three-point shear
correlations and the third moment of the mass aperture statistic using the
first 3 years of data from the Dark Energy Survey. We additionally obtain the
first measurements of the configuration and scale dependence of the four
three-point shear correlations which carry cosmological information. With the
third-order mass aperture statistic, we present tomographic measurements over
angular scales of 4 to 60 arcminutes with a combined statistical significance
of 15.0$\sigma$. Using the tomographic information and measuring also the
second-order mass aperture, we additionally obtain a skewness parameter and its
redshift evolution. We find that the amplitudes and scale-dependence of these
shear 3pt functions are in qualitative agreement with measurements in a mock
galaxy catalog based on N-body simulations, indicating promise for including
them in future cosmological analyses. We validate our measurements by showing
that B-modes, parity-violating contributions and PSF modeling uncertainties are
negligible, and determine that the measured signals are likely to be of
astrophysical and gravitational origin.
