AlterBBN v2: A public code for calculating Big-Bang nucleosynthesis constraints in alternative cosmologies

Abstract

We present the version 2 of AlterBBN, an open public code for the calculation of the abundance of the elements from Big-Bang nucleosynthesis. It does not rely on any closed external library or program, aims at being user-friendly and allowing easy modifications, and provides a fast and reliable calculation of the Big-Bang nucleosynthesis constraints in the standard and alternative cosmologies. Program summaryProgram Title:AlterBBNProgram Files doi:http://dx.doi.org/10.17632/k7j3b9zyvf.1Licensing provisions: GNU General Public License 3Programming language: CJournal Reference of previous version: Comput. Phys. Commun. 183 (2012) 1822Does the new version supersede the previous version: YesReasons for new version:AlterBBN v2 is a major update of AlterBBN, with an expanded nuclear network, new integration methods and new cosmological scenarios.Summary of revisions:•Implementation of several numerical integration methods•Automatic error and correlation calculation•Extended nuclear network•Cosmological scenarios with decaying scalar field or reheating•Scenarios with WIMPs•Interface with the JINA REACLIB nuclear database•Parallelization using OpenMPNature of problem: Calculation of the abundance of the elements generated during Big-Bang Nucleosynthesis (BBN).Solution method:AlterBBN computes the abundance of the elements by solving the system of cosmological and Boltzmann equations for each of the isotopes. It features different numerical methods adapted to stiff problems. The cosmological equations can be modified in order to test the cosmological assumptions and test alternative scenarios.Unusual features:AlterBBN has been parallelized and use the OpenMP library.