  We study the clustering properties of z~5.7 Lyman-alpha emitters (LAEs) in a
cosmological reionization simulation with a full Lya radiative transfer
calculation. Lya radiative transfer substantially modifies the intrinsic Lya
emission properties, compared to observed ones, depending on the density and
velocity structure environment around the Lya emitting galaxy. This
environment-dependent Lya selection introduces new features in LAE clustering,
suppressing (enhancing) the line-of-sight (transverse) density fluctuations and
giving rise to scale-dependent galaxy bias. In real space, the contours of the
three-dimensional two-point correlation function of LAEs appear to be
prominently elongated along the line of sight on large scales, an effect that
is opposite to and much stronger than the linear redshift-space distortion
effect. The projected two-point correlation function is greatly enhanced in
amplitude by a factor of up to a few, compared to the case without the
environment dependent selection effect. The new features in LAE clustering can
be understood with a simple, physically motivated model, where Lya selection
depends on matter density, velocity, and their gradients. We discuss the
implications and consequences of the effects on galaxy clustering from Lya
selection in interpreting clustering measurements and in constraining cosmology
and reionization from LAEs.
