# Introduction

## Welcome to the Institute for Theoretical Physics III (Quantum Gravity)

*Image Copyright: MPI für Gravitationsphysik (Albert-Einstein-Institut), MildeMarketing, Exozet*

## Quantum Gravity

## What is Quantum Gravity?

According to our current knowledge, the foundations of physics rest on two guiding principles: General Relativity (GR) and Quantum Theory (QT). GR is Einstein’s theory of the gravitational force while QT is the cornerstone of Quantum Field Theory (QFT), the framework underlying elementary particle physics. QFT describes all known interactions of matter, that is, the electromagnetic, weak and strong force together with all elementary particles, that is, fermions (the charged leptons such as the electron, the neutral leptons such as the electron neutrino, and the quarks, such as up and down quarks which are the building blocks for neutron and proton) and bosons (photon, W-and Z bosons and gluon). Together these particles are embedded into the standard model of all matter. The only interaction that is not described by QT today is the gravitational interaction. We refer the reader to the Research page, in order to understand why this is an important problem of foundational physics, why a combined theory of GR and QT, called Quantum Gravity (QG), is necessary, why such a synthesis is a challenge for theoretical and mathematical physics and how QG connects with the most interesting questions and puzzles of contemporary high precision experimental cosmology and astrophysics.

## The Institute

The Institute for Theoretical Physics III is a research group at the Friedrich-Alexander-University Erlangen-Nuremberg with focus on Quantum Gravity. The Institute is part of the ECAP, the Erlangen Centre for Astroparticle Physics.

## Our Key Topics

## Latest News

## PhD defense

The PhD defense (Rigorosum) of David Winnekens has been scheduled for Wed 07.06.2023 14:15 in the seminar room of ECAP Lab. Everybody is cordially invited.

## Awards for members of the institute

We congratulate Dr. Sepideh Bakhoda and Dr. Susanne Schander for being awarded with the department’s Ohm Prize for the best PhD theses in the academic year 2021/2022. Furthermore, we congratulate Prof. Dr. Hanno Sahlmann for receiving the department’s Teaching Award and Max Joseph Fahn (PhD stude...

## Paper alerts

There are several new preprints of our group members on the arXiv from late February and March: "Quantum Reference Frames at the Boundary of Spacetime" by Wolfgang Wieland together with Viktoria Kabel and Caslav Bruckner, available here: https://arxiv.org/abs/2302.11629 "Corner symmetry and ...

## PhD defense

The PhD defense (Rigorosum) of Thomas Zilker has been scheduled for 20.4.2023 12:00 in the seminar room of ECAP Lab. Everybody is cordially invited.

## Paper alert: A Fock space structure for the diffeomorphism invariant Hilbert space of loop quantum gravity and its applications

There is a new preprint "A Fock space structure for the diffeomorphism invariant Hilbert space of loop quantum gravity and its applications" by our group members Hanno Sahlmann and Waleed Sherif, available on arXiv https://arxiv.org/abs/2302.03612 now.