Gemini
A Toolkit for Analytical Models of Inhomogeneous Structure Formation
Gemini is a program that can be used as a toolkit
to evaluate the quantities derived
in
"An Analytical Approach to Inhomogeneous Structure Formation."
It extends standard Press-Schechter theory to inhomogeneous
situations, by reconstructing the statistics of dark matter halos
forming at two points, separated by a fixed comoving
distance.
In the past, analytical treatments
were only able to study structure formation in an average
sense, or treat a limited class of problems by
various extensions and approximations.
Gemini
reconstructs all of these results and much more;
in fact, it can construct the statistics of two halos of
any two masses, any two collapse redshifts, separated by
any distance.
For any two points it computes:
-
The bivariate mass function
(dn1dn2
/dM1dM2),
which is the product of the halo mass functions at the two points.
-
The bivariate cumulative mass fraction
(F1F2), which
is the product of the cumulative mass fractions in halos above some
mass,
at each point.
-
The bivariate mixed-mass function
(dn1 F2
/dM1),
which is the product of the halo mass function at one point,
and the cumulative mass fraction at the other point.
These quantities account for the joint, correlated statistics of
halos forming at the two points. These results can also be used to
construct various forms of the nonlinear bias, which are compared
with standard expressions in the figure on the right (see Figure 11
of the paper for greater detail).
It was developed by
Evan Scannapieco
(evan@arcetri.astro.it)
and
Rennan Barkana
(barkana@wise.tau.ac.il)
who are available to answer questions concerning its use.
To download Gemini click here.
For information on the individual routines that
make up this package click here.
Background: Franz Niklaus König: Celestial atlas (1826)
The diaphanous "Atlas céleste" (plate 1-27, 30)
Evan Scannapieco, evan@arcetri.astro.it