Enrico Pajer - Field Theory in Cosmology

These lectures provide an introduction to Quantum Field Theory methods used to describe the cosmology of the very early universe and in particular the quantum generation of primordial perturbations during inflation. After a lightning review of cosmology we will learn about quantizing scalars and gravitons in cosmological (curved) spacetime and to compute cosmological correlators using the in-in (canonical) formalism. We will briefly discuss the Effective Field Theory approach to gravity and derive various predictions for primordial non-Gaussianity (mostly bispectra). The notes end with a discuscussion of cosmological soft theorems and Maldacena's consistency relation.


Complete PDF File

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Contents

  1. A quick review of background cosmology
  2. Free filds on curved backgrounds
  3. Interacting fields and the in-in formalism
  4. Correlators from P(X,phi) theories
  5. Gravity
  6. Symmetries and soft theorems
  7. Phenomenology

Problem Sheets

These example sheets are from the L 2020 and L 2021 version of the course.