The international seminar on asymptotic safety was founded in spring 2011, with the intention of bringing the asymptotic-safety community together, and providing a platform for talks on asymptotic safety in and beyond quantum gravity, as well as related topics in quantum gravity and quantum field theory.

Upcoming seminars

Focus Seminar: The graviton propagator in Asymptotic Safety (Benjamin Knorr, Alessia Platania, and Manuel Reichert)


Seminar Date:

The propagator stores important information about the causality and unitarity of a theory, and is related to the spectral function, if it exists. Studying the propagator could provide crucial steps towards answering whether asymptotically safe quantum gravity can provide a unitary theory of quantum gravity.

Manuel Reichert: Lorentzian quantum gravity and the graviton spectral function


Seminar Date:

We present the first direct and non-perturbative computation of the graviton spectral function in quantum gravity. This is achieved with the help of a novel Lorentzian renormalisation group approach, combined with a spectral representation of correlation functions. We find a positive graviton spectral function, show...

Saswato Sen: Asymptotic safety and freedom in higher derivative gravity


Seminar Date:

We compute non-perturbative flow equations for the couplings of quantum gravity in fourth order of a derivative expansion. The gauge invariant functional flow equation for arbitrary metrics allows us to extract β-functions for all couplings. In our truncation we find two fixed points. One corresponds to asymptotical...

Tom Steudtner: Explaining B-Anomalies with safe Z' extensions


Seminar Date:

U(1)’ extensions of the SM with generation-dependent couplings to quarks and leptons are a popular explanation of anomalies in rare B-decays, such as the R_K and R_K* observables. However, a critical issue with such models is often ignored – most configurations feature a Landau pole in the new gauge coupling that is...

Renata Ferrero: Relational Observables in Asymptotically Safe Gravity


Seminar Date:

One of the greatest issues for a quantum theory of gravitation is how to generalise the notion of local observable quantities. A viable approach is to construct a physical local reference frame and give physical meaning to the components of any tensor evaluated in this frame: all measurements of tensor or scalar fie...

Chris Ripken: De Sitter scattering amplitudes in the Born approximation


Seminar Date:

A basic calculation in QFT is the construction of the Yukawa potential from a tree-level scattering amplitude. In the massless limit, this reproduces the 1/r potential. For gravity, scattering mediated by a massless graviton is thus consistent with the Newtonian potential. In de Sitter spacetime, the cosmological co...

The organizers

If you are interested in attending the seminars and joining the community, please contact Aaron Held or Marc Schiffer to join the corresponding mailing list.

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Astrid Eichhorn

Astrid is an Associate Professor at CP3-Origins, University of Southern Denmark, Villum Young Investigator and Perimeter Institute Visiting Fellow. She works on building connections in quantum gravity: connections between quantum-gravity approaches, connections between fundamental theory and phenomenology, and connections between neighboring research communities. more

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Aaron Held

Aaron works on phenomenological constraints in quantum and classical effective field theories of gravity. Currently, DAAD Prime Fellow at Jena University and The Princeton Gravity Initiative.

Marc Schiffer

Marc works on asymptotically safe gravity-matter systems using functional and lattice methods. Currently, Postdoctoral researcher at Perimeter Institute.