Lectures on modified gravity: Rodolphe Cledassou/Euclid summer school 2026
Léo Vacher
Lecture notes
- I. Foundations of general relativity
- What to modify? Foundations of general relativity
- Empirical validation of general relativity I: solar system and astrophysical constraints
- Empirical validation of general relativity II: Fundamental constants
- Empirical validation of general relativity III: Gravity and cosmology
- General relativity: field theory or geometry?
- Alternative but equivalent formulations: the trinity of gravity
- Other formulations and useful tools: ADM formalism, Palatini action, forms and tetrads
- Lovelock theorem
- II. Going beyond GR: phenomenology
- Why going beyond general relativity?
- How to go beyond general relativity?
- Lovelock gravity
- Einstein vs Jordan frames
- Brans-Dicke, and scalar-tensor theories
- Scalar fields: Horndeski theories
- Higher terms: $f(R)$, $f(Q)$, $f(T)$
- Massive gravity
- Torsion
- Escaping the constraints: Screening
- III.Going beyond GR: high energies
- Is gravity quantum?
- Gravity, black holes and thermodynamics
- High energies and swampland conjectures
- String theory
- Loop quantum gravity
Slides
- Full pdf of lecture notes