Big Bang nucleosynthesis ( BBN ) theory predicts the abundances of the light elements D , ^ { 3 } He , ^ { 4 } He and ^ { 7 } Li produced in the early universe .
The primordial abundances of D and ^ { 4 } He inferred from observational data are in good agreement with predictions , however , the BBN theory overestimates the primordial ^ { 7 } Li abundance by about a factor of three .
This is the so-called “ cosmological lithium problem ” .
Solutions to this problem using conventional astrophysics and nuclear physics have not been successful over the past few decades , probably indicating the presence of new physics during the era of BBN .
We have investigated the impact on BBN predictions of adopting a generalized distribution to describe the velocities of nucleons in the framework of Tsallis non-extensive statistics .
This generalized velocity distribution is characterized by a parameter q , and reduces to the usually assumed Maxwell-Boltzmann distribution for q = 1 .
We find excellent agreement between predicted and observed primordial abundances of D , ^ { 4 } He and ^ { 7 } Li for 1.069 \leq q \leq 1.082 , suggesting a possible new solution to the cosmological lithium problem .