Djordje MINIC (Virginia Tech, USA)

**The Challenges of Quantum Gravity **(1 Lecture: May 16 @ 3 pm CET) ** **(Completed)

Flaminia GIACOMINI (ETH Zürich, Switzerland)

**Quantum information tools at the interface between quantum theory and gravity **(4 Lectures: May 22, 23, 24, 25 @ 2 pm CET) (Completed)

Hal HAGGARD (Bard College, USA)

**The Basics of Loop Quantum Gravity **(5 Lectures: June 7, 14, 21, 28, July 5 @ 3 pm CET) (Completed)

John DONOGHUE (University of Massachusetts Amherst, USA)

**Perturbative Quantum Gravity** (6 Lectures: June 8, 13, 15 @ 3 pm CET (Completed Part I), September 18, 20, 22 @ 3 pm CET)

This mini-course will focus on treating General Relativity as a perturbative quantum field theory. We will cover the field-theoretic construction and quantization of the theory. Useful field theory techniques will be introduced. Of course, renormalization will be discussed in detail. There will be an introduction to effective field theory, and we will see how the use of effective field theory techniques allows the calculation of quantum effects at ordinary scales. Finally, we discuss the limits of these techniques and try to point out some of the open directions.

See https://blogs.umass.edu/grqft/ for more details and references.

Horatiu NASTASE (São Paulo State University, Brazil)

**String Theory **(4 Lectures: September 21, 28, and October 19, 26 @ 3 pm CET)

Title of lectures: "AdS/CFT and Quantum Gravity"

Lecture 1: "Supergravity and String Theory"

Lecture 2: "AdS/CFT and its nontrivial tests"

Lecture 3: "Gauge/gravity dualities, the pp wave correspondence and spin chains"

Lecture 4: "Holographic cosmology"

Abstract: "In this series of lectures I will explore how the AdS/CFT correspondence helps us understand Quantum Gravity. As AdS/CFT is based on string theory, in the first lecture I will describe the main aspects of supergravity and string theory. In the second lecture, I will describe the main example of the AdS/CFT correspondence, N=4 SYM vs. string theory in the AdS_5xS^5 background, and the variety of nontrivial tests it has passed, including at nontrivial coupling g_s and string length \alpha'. In the third lecture, I will describe the generalizations to gauge/gravity dualities, within string theory ("top-down") and outside ("bottom-up"), and how quantum strings (as opposed to fields for particles) are obtained in the pp wave correspondence, from spin chains. In the fourth lecture, I will describe how purely quantum gravitational effects (at strong coupling) are obtained from field theory in holographic cosmology, a phenomenological application of AdS/CFT to cosmology, leading to an alternative, strongly coupled version, of inflation."

Astrid EICHHORN (University of Southern Denmark, Denmark)

**Non-perturbative Renormalization for Quantum Gravity **(3 Lectures: October 16-18 @ 3 pm CET)

I will introduce the asymptotic-safety paradigm and how it can make a quantum field theory both ultraviolet complete and predictive. I will discuss mechanisms to generate asymptotic safety, which rely on the effect of quantum fluctuations and will provide examples for theories which are asymptotically safe and do not contain the gravitational interaction. Then, I will review the existing evidence for asymptotic safety in quantum gravity. My main focus will be on results from functional Renormalization Group techniques, but I will also mention results from lattice approaches such as Causal Dynamical Triangulations. Finally, I will discuss the phenomenology of asymptotic safety with a focus on its predictions for particle physics. The key point here will not be effects of quantum gravity at Planckian energies, but an explanation how the interplay of quantum gravity and matter at the Planck scale could result in predictions of the values of some of the couplings in the Standard Model of particle physics and beyond. I will finish with implications of asymptotic safety for the dark sector of the universe.

__Suggested reading material:__

- An introduction to asymptotic safety with non-gravitational and gravitational examples: https://inspirehep.net/literature/1699056
- An up-to-date review of the interplay of asymptotically safe gravity with matter: https://inspirehep.net/literature/2614951
- Two introductions to functional Renormalization Group techniques in quantum gravity: https://inspirehep.net/literature/2637403 and https://inspirehep.net/literature/1790613
- Critical reflections on asymptotic safety, which address open problems and challenges, but also misconceptions about the approach https://inspirehep.net/literature/1791276

Andrea PUHM (École Polytechnique, France)

**AdS/CFT and Holography**

*Yet to be published!*