  This monograph provides a largely self--contained and broadly accessible
exposition of two cosmological applications of algebraic quantum field theory
(QFT) in curved spacetime: a fundamental analysis of the cosmological evolution
according to the Standard Model of Cosmology and a fundamental study of the
perturbations in Inflation. The two central sections of the book dealing with
these applications are preceded by sections containing a pedagogical
introduction to the subject as well as introductory material on the
construction of linear QFTs on general curved spacetimes with and without gauge
symmetry in the algebraic approach, physically meaningful quantum states on
general curved spacetimes, and the backreaction of quantum fields in curved
spacetimes via the semiclassical Einstein equation. The target reader should
have a basic understanding of General Relativity and QFT on Minkowski
spacetime, but does not need to have a background in QFT on curved spacetimes
or the algebraic approach to QFT. In particular, I took a great deal of care to
provide a thorough motivation for all concepts of algebraic QFT touched upon in
this monograph, as they partly may seem rather abstract at first glance. Thus,
it is my hope that this work can help non--experts to make `first contact' with
the algebraic approach to QFT.
