The lithium problem, a phenomenologist's perspective
  Thirty years after the first observation of the 7Li isotope in the atmosphere
of metal-poor halo stars, the puzzle about its origin persists. Do current
observations still support the existence of a "plateau": a single value of
lithium abundance, constant over several orders of magnitude in the metallicity
of the target star? If this plateau exists, is it universal in terms of
observational loci of target stars? Is it possible to explain such observations
with known astrophysical processes? Can yet poorly explored astrophysical
mechanisms explain the observations or do we need to invoke physics beyond the
standard model of Cosmology and/or the standard model of Particle Physics to
explain them? Is there a 6Li problem, and is it connected to the 7Li one? These
questions have been discussed at the Paris workshop Lithium in the Cosmos, and
I summarize here its contents, providing an overview from the perspective of a
phenomenologist.
