The theory of stellar evolution is by now well established, after more than half a
century of continuous development, and its main predictions confirmed by various
empirical tests. As a consequence, we can now use its results with some confidence,
and obtain vital information about the structure and evolution of the universe from
the analysis of the stellar components of local and high redshift galaxies.
A wide range of techniques developed in the last decades make use of stellar
evolution models, and are routinely used to estimate distances, ages, star formation
histories and the chemical evolution of galaxies; obtaining this kind of information is,
in turn, a necessary first step to address fundamental cosmological problems like the
dynamical status and structure of the universe, the galaxy formation and evolution
mechanisms. Due to their relevance, these methods rooted in stellar evolution should
be part of the scientific background of any graduate and undergraduate astronomy and
astrophysics student, as well as researchers interested not only in stellar modeling,
but also in galaxy and cosmology studies.
In this respect, we believe there is a gap in the existing literature at the level of
senior undergraduate and graduate textbooks that needs to be filled. A number of
good books devoted to the theory of stellar evolution do exist, and a few discussions
about the application of stellar models to cosmological problems are scattered in
the literature (especially the methods to determine distances and ages of globular
clusters). However, an organic and self-contained presentation of both topics, that is
also able to highlight their intimate connections, is still lacking. As an example, the
so-called 'stellar population synthesis techniques' - a fundamental tool for studying
the properties of galaxies - are hardly discussed in any existing stellar evolution
textbook.