Big bang nucleosynthesis


I built a Multi-Species 3D Relativistic thermalization simulation technique usable to study the thermalization(or Brownian motion) of any system with various species of particles. Codes available in Ref. [2] and algorithm described in Ref. [3].
Further, I used this simulation tool to obtain the equilibrium statistics for baryons during Big bang nucleosynthesis (BBN) era of the early universe.

A schematic illustration of the algorithm for performing scatterings in the simulation code. Several frame changes and rotations are needed to be performed to make the scattering events solvable.

A 3D Multi-Specie Relativistic thermalization. Here electrons and positrons are describe by their relativistic Fermi-Dirac statistics, whereas protons- nonrelativistic in these temperatures- starts with zero energy and attains a Maxwell-Boltzmann distribution.

Same simulation for a 2D Multi-Specie Relativistic thermalization.

Same simulation for a 1D Multi-Specie Relativistic thermalization.

References:
[1] github.com/AtulKedia93/Multicomponent_relativistic_thermlization .
[2] AK, N. Sasankan, G.J. Mathews, M. Kusakabe, Simulations of multicomponent relativistic thermalization, Phys. Rev. E 103, 032101 (2021).
[3] M. Kusakabe, AK, G.J. Mathews, N. Sasankan, Distribution function of nuclei from e± scattering in the presence of a strong primordial magnetic field, Phys. Rev. E 103, 032101 (2021).
[4] N. Sasankan, AK, M. Kusakabe, G.J. Mathews, Analysis of the multicomponent relativistic Boltzmann equation for electron scattering in big bang nucleosynthesis, Phys. Rev. D 101, 123532 (2020).
[5] G.J. Mathews, AK, N. Sasankan, M. Kusakabe, Y. Luo, T. Kajino, D.G. Yamazaki, T. Makki, M.El Eid, Cosmological solutions to the Lithium problem, JPS Conf. Proc. 31, 011033 (2020).