Title and Abstract for Andrej's talk:
Anisotropic
assembly
bias
in
theory,
simulations
and
data
Abstract:
Clustering
of
matter
on
large
scales
provides
an
important
source
of
information
on
key
cosmological
parameters. To
extract
this
information
we
need
to
understand
the
relation
between
the
tracers
we
observe
and
the
underlying
matter
field. The
clustering
strength
of
halos
and
galaxies
on
large
scales
is
linearly
biased
compared
to
the
matter
clustering.
This
linear
bias
mainly
depends
on
halo
mass
and
redshifts,
though
selections
based
on
other
scalar
halo
properties (age,
spin,
concentration
etc.)
show
additional
bias
dependences
—
called
assembly
bias. Furthermore,
non-scalar
halo
properties:
shapes,
velocity
dispersion
and
angular
momentum,
are
correlated
with
the
large-scale
tidal
field. Selection
effects
that
couple
to
these
non-scalar
halo
properties
can
produce
anisotropic
clustering even
in
real-space
and
act
as
a
contaminant
to
redshift-space
distortion
measurements,
through
an
anisotropic
assembly
bias
(AB).
I
will
discuss
our
recent
results
on
studying
the
halo
AB
using
a
large
number
of
numerical
simulations.
Then
I
will
present
the
first
observational
evidence
of
the
galaxy
AB
in
BOSS
DR12
galaxies.
Finally,
I
will
show
other
consequences
and
future
prospects.