Gravity and Other Fields Under the Volcano

Contribution List

2. Resummation, renormalons and asymptotic safety

Oleg Antipin

10/06/2019, 09:15

27. Rethinking asymptotic freedom

Luca Zambelli

10/06/2019, 10:00

The renormalization-group flow of Higgs-Yukawa models with a non-Abelian gauge sector has been studied for several decades by adopting two simplifying assumptions: that the theory is perturbatively renormalizable and that all mass terms are negligible at high energies. Within this theoretical framework, total asymptotic freedom appears to be a rare phenomenon which severely constrains the...

24. Stability Issues with Broken Supersymmetry and Some Clues for Early Cosmology

Augusto Sagnotti (PI)

10/06/2019, 11:15

1. Fakeons and quantum gravity

Damiano Anselmi (PI)

10/06/2019, 12:00

26. Aspects of higher spin theories

Ergin Sezgin

10/06/2019, 14:15

I will describe the salient features of higher spin theories as gauge theories based on infinite dimensional extension of (A)dS algebras, a la Vasiliev. The fully nonlinear equations of motion are formulated compactly on a product of spacetime with a noncommutative twistor space. I will highlight a powerful method for finding exact solutions of the theory which crucially employs the twistor...

21. Metric-affine quantum gravity

Roberto Percacci

10/06/2019, 15:00

16. Massive Gravity

Fabrizio Nesti (TS)

10/06/2019, 16:15

I describe the efforts to implement a theory of massive graviton and how the request for a weakly coupled phase leads to the need to break not only general covariance, but also Lorentz symmetry. Hamiltonian analysis of the nonperturbative degrees of freedom, as well as cosmology and exact solutions generalizing the Schwarzschild one are described.

22. Analytic Coupling Structure of Large N_f (Super) QED and QCD

Manuel Reichert

10/06/2019, 17:00

17. Ultraviolet completion and predictivity from a minimal parameterization of Beyond-Standard-Model physics

Carlos Nieto

10/06/2019, 17:35

I will discuss the fate of the U(1) gauge coupling under the inclusion of vector-like fermions in the standard model. Then, motivated by results on quantum gravity contributions to the running of gauge and Yukawa couplings, I talk about the effect of simple but general corrections on the running of those couplings from the EW to large enough energy scales. One of our goals is to have an...

23. Background Independent Quantum Field Theory and Gravitating Vacuum Fluctuations

Martin Reuter

11/06/2019, 09:00

14. Perturbatively renormalizable quantum gravity

Tim Morris

11/06/2019, 09:45

The Wilsonian renormalization group (RG) requires Euclidean signature. The conformal factor of the metric then has a wrong-sign kinetic term, which has a profound effect on its RG properties. In particular around the Gaussian fixed point, it supports a Hilbert space of renormalizable interactions involving arbitrarily high powers of the gravitational fluctuations. These interactions are...

20. Effective universality and unitarity in quantum gravity & the spectral function of the graviton

Jan Pawlowski

11/06/2019, 11:00

10. Fixed points of gauge theories and gravity

Daniel Litim

11/06/2019, 11:45

12. Wilson loops and curvature in (quantum) gravity

Renate Loll

11/06/2019, 14:00

6. Towards a phenomenology of scale invariance

Astrid Eichhorn

11/06/2019, 14:45

Asymptotic safety, i.e., scale invariance in the ultraviolet, is a compelling proposal for the nature of fundamental interactions. Understanding its phenomenological consequences is a critical challenge, as any physical theory requires testing through confrontation with observations and experiments. In this talk I will discuss potential consequences of asymptotic safety for (Beyond) Standard...

18. Asymptotic safety and the dimension of the critical surface

Nobuyoshi Ohta

11/06/2019, 16:00

19. Geometry of the theory space and the functional renormalization group

Carlo Pagani

11/06/2019, 16:45

We consider the theory space as a manifold whose coordinates are given by the couplings appearing in the effective action. We discuss how to introduce connections on this theory space in the framework of the functional renormalization group (FRG). Finally, we discuss possible developments and limitations of this formalism and how to overcome such difficulties in the FRG setting.

7. Frame (In)equivalence in Quantum Field Theory and Cosmology

Kevin Falls

11/06/2019, 17:30

I will discuss whether or not scalar-tensor theories in the Einstein and Jordan frames are equivalent once quantum corrections are taken into account. To understand this problem it is crucial to carefully define the path integral measure that arises in the quantization of the equivalent classical theories. Generically two measures will differ if the spacetime metrics in the two theories are...

13. Indirect Dark Matter searches and fundamental physics with present- and next-generation Cherenkov telescopes

Saverio Lombardi (INAF-OAR and ASI Science Data Center, Rome, Italy)

12/06/2019, 09:00

Very-high energy (VHE, E>~50 GeV) gamma rays of cosmic origin can reveal unique information on paramount open issues of fundamental physics while also providing a complementary probe to laboratory experiments and particle accelerators. In fact, the search for VHE gamma-ray signatures from the annihilation or decay of dark matter (DM) particles is a promising method for identifying DM,...

25. Gravitational Waves: a novel powerful tool to test fundamental theories

Mairi Sakellariadou

12/06/2019, 09:45

The recent discoveries of gravitational waves (GWs)
from the LIGO and Virgo interferometers opened a new
era in GWs as well as multi-messenger astronomy, and offered new ways to test gravitational theories beyond Einstein's theory of General Relativity.
Very recently it has been also shown how nonperturbative quantum gravity (QG) can affect the GW luminosity distance associated with the long...

28. A Multi-Benefit Solution of Dark Energy problem based on the IR behavior of asymptotic safe gravity

Vasilios Zarikas

12/06/2019, 10:30

Infrared corrections that arise in some theoretical attempts to
understand Quantum Gravity may be the solution to one tantalizing problem of modern physics. Recently a novel Asymptotically Safe cosmology suggested a simple and attractive mechanism towards resolving naturally the structure
of dark energy and its associated cosmic coincidence problem. The novel idea is that the recent...

9. SO(7,7) structure of the SM fermions

Kirill Krasnov

12/06/2019, 11:25

It has been suggested in the past (by several different authors) that the Standard Model gauge group can be combined with Lorentz group. If this is done, all fermions of a single generation of the SM receive the interpretation of components of a single spinor of a pseudo-orthogonal group Spin(p,q) of dimension p+q=14. There are only two possibilities that do not lead to the fermion doubling...

3. Covariance And Spectral Geometry of Spinor Fields

Ludwik Dabrowski

12/06/2019, 12:10

All the fundamental matter particles are fermions and correspond
to spinor fields.
They arise as projective representation of the rotations
and (pseudo) orthogonal groups, and their installation on curved
space-times requires introducing of particular geometric structures.
I will discuss some of their surprising and nontrivial aspects
including the seldom discussed subtle issue of general...

4. Surprises in the O(N) models or why might the standard large N analysis fail

Bertrand Delamotte

12/06/2019, 14:25

The O(N) models are probably the most studied field theories. Everything is supposed to be known about their symmetric and symmetry broken phases as well as their critical behavior. Many analytical methods were born here and it is the textbook example for both the $\epsilon=4-d$ and the
large-$N$ expansions. We nevertheless show that several
renormalization group fixed points of this model...

5. Holography for general boundaries

Bianca Dittrich

12/06/2019, 15:10

I give a review of recent work on establishing holographic duals for quasi-local boundaries in 3D perturbative and non-perturbative gravity, as well as its extension to 4D gravity.
In particular I will show how holographic duals can be constructed as effective actions for geometric boundary observables. I will then connect this work with more standard holographic considerations at asymptotic...

8. Gravity with more or less gauging

Steffen Gielen

12/06/2019, 16:25

General Relativity is conventionally formulated as a theory with gauge invariance under the diffeomorphism group of general coordinate transformations, but there are locally equivalent formulations in terms of either a larger (additional local conformal invariance) or smaller (only "special" diffeomorphisms) group of symmetries. Other formulations with the same number of gauge generators, but...

11. Peculiarities of FRG-Quantum-Gravity

Stefan Lippoldt

12/06/2019, 17:10

In this talk I will point out some properties of general relativity, which are particularly important for the FRG. First I am going to consider the special structure of the gauge symmetry in gravity leading to a discussion of gauge invariance within asymptotic safety. Second I will highlight some consequences of boundaries in path integrals arising, e.g., when restricting the path integral to...