## about the calculator

This calculator determines the dark energy figure of merit,
defined as 1/(σ_{wa}σ_{wp}) (see DETF report), as well
as the expected cluster counts, for a large cluster survey, with
several user-specified parameters. It assumes either a single
observable-mass relation with self-calibration or two different
observable-mass relations with cross-calibration.

Additionally, the calculator optimizes follow ups to a large cluster survey using a simulated annealing algorithm, as described in
Wu, Rozo, and Wechsler 2009 (W09).

## underlying assumptions

### cosmological model

We assume a fiducial cosmology from WMAP5 (Komatsu et al 09).### mass-observable relation

We assume the mass-observable relation is parameterized as in W09, see Eq. 7 and 8.### mass function and bias

We assume the mass function of Tinker et al 08 and the bias function of Tinker 09 (in prep), see the appendix of Tinker, Wechsler & Zheng 09.### self-calibration

We assume that cosmological information from both cluster counts and counts-in-cells is used to "self-calibrate" the cluster survey. The details of our approach are described in Wu, Rozo & Wechsler 2008.

## conditions of use

This is a pre-release version. It may be used pre-release (with no guarantees!) if users:

- email cluster-calc@lists.stanford.edu so they will be notified of upcoming releases,
- reference http://risa.stanford.edu/cluster, and
- for use in published work, check this website for the upcoming paper which will describe the calculator, and cite W09 for calculations which include followups.

## download

There are two versions of the calculator.

### CLUSTER single (v_alpha11.29.09):

Calculates cluster counts and DE figure of merit for a cluster survey with a single cluster mass proxy, with user-specified parameters. Calculates the improved DE figure of merit and optimal mass and redshift bins for a user-specified number of followups with a second observable.

### CLUSTER cross (v_alpha11.29.09):

Calculates cluster counts and DE figure of merit for two overlapping cross-calibrated cluster surveys with different mass proxies. Calculates the improved DE figure of merit and optimal mass and redshift bins for a user-specified number of followups with a third observable.

The calculators run calculations on the client's computer, and
require Java SE5 (or later) to run. If your computer downloads the file but does
not open it, try running the following from the command line:

Cluster Single:

javaws
http://risa.stanford.edu/cluster/FisherCalculator_JavaSE5.jnlp

Cluster Cross-Calibrating:

javaws
http://risa.stanford.edu/cluster/FisherCalculator_JavaSE5_cross.jnlp

## comments and suggestions

are encouraged! Please email cluster-calc@lists.stanford.edu. Current planned improvements include:

- cost proxy as implemented in W09
- user-specified choice of mass-observable relation
- mass threshold which changes with redshift

## credits

CLUSTER was developed by Adam Bouland, Hao-Yi Wu, and Risa Wechsler, with support from Stanford University.