  Attempts to connect string theory with astrophysical observation are hampered
by a jargon barrier, where an intimidating profusion of orientifolds, Kahler
potentials, etc. dissuades cosmologists from attempting to work out the
astrophysical observables of specific string theory solutions from the recent
literature. We attempt to help bridge this gap by giving a pedagogical
exposition with detailed examples, aimed at astrophysicists and high energy
theorists alike, of how to compute predictions for familiar cosmological
parameters when starting with a 10-dimensional string theory action. This is
done by investigating inflation in string theory, since inflation is the
dominant paradigm for how early universe physics determines cosmological
parameters.
  We analyze three explicit string models from the recent literature, each
containing an infinite number of "vacuum" solutions. Our numerical
investigation of some natural candidate inflatons, the so-called "moduli
fields", fails to find inflation. We also find in the simplest models that,
after suitable field redefinitions, vast numbers of these vacua differ only in
an overall constant multiplying the effective inflaton potential, a difference
which affects neither the potential's shape nor its ability to support
slow-roll inflation. This illustrates that even having an infinite number of
vacua does not guarantee having inflating ones. This may be an artifact of the
simplicity of the models that we study. Instead, more complicated string theory
models appear to be required, suggesting that explicitly identifying the
inflating subset of the string landscape will be challenging.
