TRISEP 2023

This page is for the TRISEP summer school at Perimeter Institute. The lecture notes, references, and links are posted here.

Lecture 1 Notes for the first lecture and the recording. Review of gauge theory construction. The energy momentum tensor. Gauging spacetime translations. First success – energy-momentum as source. Second sucess – one graviton exchange. Third success – Schroedinger Equation for gravity. Covariant derivative and curvatures. Metricity. Weak field expansion. The Feynman rules for gravity. A first loop calculation.

Lecture 2 Notes for the second lecture and the recording. Review. Effective field theory via two examples. QED with a heavy top quark. Renormalize and measure. Appelquist-Carazzone. Uncertainty principle. The linear sigma model. Direct construction of an Effective Field Theory. Haag’s theorem. EFT is a full QFT. Renormalizing an unrenormalizable theory and making predictions. Power counting. The background field method. The a_2 coefficient and renormalization.

Lecture 3 Notes for the third lecture and the recording. Review. Developing the Effective Field Theory for gravity. Background field for General Relativity. Gauge fixing. Ghost stories. Calculating the ghost Lagrangian. The general gravitational action. Renormalization from a scalar loop. Renormalization from gravitons. The non-relativistic gravitational potential. The nature of the quantum correction. Bending of photons and gravitons. Universality of the potential. Classical effects from quantum loops. Geodesics become uncontrollable. No quantum metric. Limits of the effective field theory.

Download your free open access copy of Dynamics of the Standard Model, which contains material which I will use during this mini-course.

I always recommend that you should read Feynman’s paper: Quantum Theory of Gravitation . It is informative and also fun.

A written reference with much more detail is the EPFL Lectures on General Relativity as a Quantum Field Theory, which is the record of a longer lecture series, co-written with Mikhail Ivanov and Andrey Shkerin

Collected references and lectures