Cosmological lithium problem

Minutes after the Big Bang, the universe was made almost entirely of hydrogen and helium, with trace amounts of lithium and beryllium, and negligibly small abundances of all heavier elements.

[10] Spectroscopic observations of stars in NGC 6397, a metal-poor globular cluster, are consistent with an inverse relation between lithium abundance and age, but a theoretical mechanism for diffusion has not been formalized.

Considering the possibility that BBN predictions are sound, the measured value of the primordial lithium abundance should be in error and astrophysical solutions offer revision to it.

For example, systematic errors, including ionization correction and inaccurate stellar temperatures determination could affect Li/H ratios in stars.

In summary, accurate measurements of the primordial lithium abundance is the current focus of progress, and it could be possible that the final answer does not lie in astrophysical solutions.

For incorrect reactions, major thoughts lie within revision to cross section errors and standard thermonuclear rates according to recent studies.

[26][27] BBC Science Focus wrote in 2023 that "recent research seems to completely discount" such theories; the magazine held that mainstream lithium nucleosynthesis calculations are probably correct.

With the fully operational Large Hadron Collider (LHC), much of minimal supersymmetry lies within reach, which would revolutionize particle physics and cosmology if discovered;[7] however, results from the ATLAS experiment in 2020 have excluded many supersymmetric models.

[29][30] Changing fundamental constants can be one possible solution, and it implies that first, atomic transitions in metals residing in high-redshift regions might behave differently from our own.

Additionally, Standard Model couplings and particle masses might vary, and variation in nuclear physics parameters would be needed.

This "Schramm plot" [ 3 ] depicts primordial abundances of 4 He, D, 3 He, and 7 Li as a function of cosmic baryon content from standard BBN predictions. CMB predictions of 7 Li (narrow vertical bands, at 95% CL ) and the BBN D + 4 He concordance range (wider vertical bands, at 95% CL) should overlap with the observed light element abundances (yellow boxes) to be in agreement. This occurs in 4 He and is well constrained in D, but is not the case for 7 Li, where the observed Li observations lie a factor of 3−4 below the BBN+WMAP prediction.
Proton–proton II chain reaction
Stable nuclides of the first few elements
Abundances of the chemical elements in the Solar System. Hydrogen and helium are most common, residuals within the paradigm of the Big Bang. [ 8 ] Li, Be and B are rare because they are poorly synthesized in the Big Bang and also in stars; the main source of these elements is cosmic ray spallation .
Nova Centauri 2013 is the first in which evidence of lithium has been found. [ 14 ]