# A new cosmic shear function:

Optimised E-/B-mode decomposition on a finite interval

## Reference

Liping Fu, Martin Kilbinger, 2009, arXiv:0907.0795

## Description

We have introduced a new cosmic shear statistic which decomposes the shear correlation into E- and B-modes on a finite angular interval. The new function is calculated by integrating the shear two-point correlation function with a filter function. The filter function fulfills the E-/B-mode decomposition constraints given in Schneider & Kilbinger (2007).

## Download, install, and run the code

Download the tar file decomp.tgz. Extract the archive with

`tar xzf decomp.tgz`

To compile and run the code:

`cd Demo
make links
make decomp_eb
decomp_eb `

The package `fftw3` has to be installed. If it is not in a standard directory, `fftw3.h` is looked for in `$(FFTW)/include` and `libfftw3.a` in `$(FFTW)/lib`. Change the variable `FFTW’ in the Makefile accordingly. You can download `fftw3` from http://www.fftw.org.

The program produces two files, `Tpm` containing the filter functions *T*_{+} and *T*_{–}, and `REB` containing the shear functions R_{E} and R_{B}.

## Authors

Liping Fu, Martin Kilbinger (martin.kilbinger@cea.fr)