linan7788626/cosmology

Applications to simulate gravitational lensing, through ray tracing and shear calculation. See http://research.davecoss.com for more details.

Cosmology Applications

About

This software package provides tools to simulate gravitational lensing using two different techniques, ray tracing and shear calculation. This software was originally developed as part of my doctoral dissertation (http://thesis.davecoss.com).

Since I finished my dissertation (May 2010), I have continued to work on this software. In fact, it is still a work in progress, which mostly means adding features. Currently, this includes improving the parallel performance of ray_trace_ellipse and improving the script-ability of physcalc.

Ray Tracing

ray_trace_ellipse is a program that calculations deflection angles on a grid for light passing may a deflecting mass distribution. Using MPI, ray_trace_ellipse may calculate deflection in parallel across network connected computers, such as cluster.

Shear

Gravitational Lensing Shear is calculated using the relationship of convergence and shear, described by a set of coupled partial differential equations. This is done using the program physcalc.

Requires

This software suite requires two libraries that I developed in parallel to this work, which are also available under the GNU GPL.

• libdnstd is a general purpose C++ library that provides various utility functions and classes, generally mathematically focused. This may be found at https://github.com/kd0kfo/libdnstd.git.

• libmygl is a C++ library that provides subroutines and classes to carry out gravitational lensing simulations. This library is located at https://github.com/kd0kfo/libmygl.git.

Additionally, as of version 2.10, this software stored Planes as NetCDF files. This is freely available here: http://www.unidata.ucar.edu/software/netcdf/

physcalc requires Flex and Bison. They can be found at http://flex.sourceforge.net/ and http://www.gnu.org/software/bison/ respectively.

Citation

Please cite use of this software or derivatives of this software as: Coss, D., "Weak Shear Study of Galaxy Clusters by Simulated Gravitational Lensing.", Ph.D. Dissertation, University of Missouri -- St Louis, 2010.

License

This software is available under the GNU General Public License version 3 (see COPYING).