PRImordial MATter

General description

PRIMAT is a Mathematica code dedicated to the computation of light elements abundances at the end of the Big-Bang Nucleosynthesis (BBN). It computes the evolution of these abundances in the first minutes after the Big-Bang so as to obtain the frozen values when the temperature dropped below 108 degrees. It allows to explore the dependence of light elements abundances on cosmological parameters, such as baryon density or number of neutrino species, but also to estimate from a Monte-Carlo method the uncertainty in these predictions due to uncertainties in nuclear reaction rates.


The details of the method used to solve numerically for the thermodynamics, cosmology and nuclear reactions in the early universe are available in an associated publication (Physics Reports, 04, (2018) 005 [arXiv:1801.08023]). Please cite it along with this website if you use it in BBN related publications, using this bibtex file. See also updated described in MNRAS 2021 [arXiv:2011.11320].

Please feel free to download and examine the list of recent nuclear reaction rates which are not yet included in PRIMAT, and modify accordingly PRIMAT reaction rates file by simple replacement to assess their effect on final abundances.


The programs in this page are distributed as free software under the GNU General Public License. They are distributed in the hope that they will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU GPL for more details.

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