Cosmic voids uncovered — first-order statistics of depressions in the biased density field. (arXiv:1902.04585v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Ronconi_T/0/1/0/all/0/1">Tommaso Ronconi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Contarini_S/0/1/0/all/0/1">Sofia Contarini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marulli_F/0/1/0/all/0/1">Federico Marulli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baldi_M/0/1/0/all/0/1">Marco Baldi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Moscardini_L/0/1/0/all/0/1">Lauro Moscardini</a>
Cosmic voids are the major volume component in the matter distribution of the
Universe. They posses great potential for constraining dark energy as well as
for testing theories of gravity. Nevertheless, in spite of their growing
popularity as cosmological probes, a gap of knowledge between cosmic void
observations and theory still persists. In particular, the void size function
models proposed in literature have been proven unsuccessful in reproducing the
results obtained from cosmological simulations in which cosmic voids are
detected from biased tracers of the density field, undermining the possibility
of using them as cosmological probes. The goal of this work is to cover this
gap. In particular, we make use of the findings of a previous work in which we
have improved the void selection procedure, presenting an algorithm that
redefines the void ridges and, consequently, their radius. By applying this
algorithm, we validate the volume conserving model of the void size function on
a set of unbiased simulated density field tracers. We highlight the difference
in the internal structure between voids selected in this way and those
identified by the popular VIDE void finder. We also extend the validation of
the model to the case of biased tracers. We find that a relation exists between
the tracer used to sample the underlying dark matter density field and its
unbiased counterpart. Moreover, we demonstrate that, as long as this relation
is accounted for, the size function is a viable approach for studying cosmology
with cosmic voids.
Cosmic voids are the major volume component in the matter distribution of the
Universe. They posses great potential for constraining dark energy as well as
for testing theories of gravity. Nevertheless, in spite of their growing
popularity as cosmological probes, a gap of knowledge between cosmic void
observations and theory still persists. In particular, the void size function
models proposed in literature have been proven unsuccessful in reproducing the
results obtained from cosmological simulations in which cosmic voids are
detected from biased tracers of the density field, undermining the possibility
of using them as cosmological probes. The goal of this work is to cover this
gap. In particular, we make use of the findings of a previous work in which we
have improved the void selection procedure, presenting an algorithm that
redefines the void ridges and, consequently, their radius. By applying this
algorithm, we validate the volume conserving model of the void size function on
a set of unbiased simulated density field tracers. We highlight the difference
in the internal structure between voids selected in this way and those
identified by the popular VIDE void finder. We also extend the validation of
the model to the case of biased tracers. We find that a relation exists between
the tracer used to sample the underlying dark matter density field and its
unbiased counterpart. Moreover, we demonstrate that, as long as this relation
is accounted for, the size function is a viable approach for studying cosmology
with cosmic voids.
http://arxiv.org/icons/sfx.gif
