149 citations · 1k across the 32 of their papers we have counts for
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On the Gravitational Origin of the QCD Axion
Georgios K. Karananas, Mikhail Shaposhnikov, Sebastian Zell
Gravity can give rise to (pseudo)scalar fields, for instance due to torsion. In particular, axions of gravitational origin have been proposed as a minimal and compelling solution t…
Weyl-invariant Einstein-Cartan gravity: unifying the strong CP and hierarchy puzzles
Georgios K. Karananas, Mikhail Shaposhnikov, Sebastian Zell
We show that the minimal Weyl-invariant Einstein-Cartan gravity in combination with the Standard Model of particle physics contains just one extra scalar degree of freedom (in addi…
Consistent particle physics in metric-affine gravity from extended projective symmetry
Will Barker, Sebastian Zell
It is well-known that the Einstein-Hilbert action exhibits a projective invariance in metric-affine gravity, generated by a single vector (just like diffeomorphisms). However, this…
Non-Polynomial Interactions as a Path Towards a Non-Renormalizable UV-Completion
Mikhail Shaposhnikov, Sebastian Zell
We propose a new class of single-field scalar quantum field theories with non-polynomial interactions leading to a two-point Green's function that can be naturally continued beyond…
Scale invariant Einstein-Cartan gravity and flat space conformal symmetry
Georgios K. Karananas, Mikhail Shaposhnikov, Sebastian Zell
We find the conditions under which scale-invariant Einstein-Cartan gravity with scalar matter fields leads to an approximate conformal invariance of the flat space particle theory…
Einstein-Proca theory from the Einstein-Cartan formulation
Will Barker, Sebastian Zell
We construct a theory of gravity in which a propagating massive vector field arises from a quadratic curvature invariant. The Einstein-Cartan formulation and a partial suppression…
Coupling Metric-Affine Gravity to a Higgs-Like Scalar Field
Claire Rigouzzo, Sebastian Zell
General Relativity (GR) exists in different formulations. They are equivalent in pure gravity but generically lead to distinct predictions once matter is included. After a brief ov…
Scale and Weyl Invariance in Einstein-Cartan Gravity
Georgios K. Karananas, Mikhail Shaposhnikov, Andrey Shkerin +1
We show how Einstein-Cartan gravity can accommodate both global scale and local scale (Weyl) invariance. To this end, we construct a wide class of models with nonpropagaing torsion…
Matter matters in Einstein-Cartan gravity
Georgios K. Karananas, Mikhail Shaposhnikov, Andrey Shkerin +1
We study scalar, fermionic and gauge fields coupled nonminimally to gravity in the Einstein-Cartan formulation. We construct a wide class of models with nondynamical torsion whose…
Einstein-Cartan gravity, matter, and scale-invariant generalization
Mikhail Shaposhnikov, Andrey Shkerin, Inar Timiryasov +1
We study gravity coupled to scalar and fermion fields in the Einstein-Cartan framework. We discuss the most general form of the action that contains terms of mass dimension not big…
Black Hole Metamorphosis and Stabilization by Memory Burden
Gia Dvali, Lukas Eisemann, Marco Michel +1
Systems of enhanced memory capacity are subjected to a universal effect of memory burden, which suppresses their decay. In this paper, we study a prototype model to show that memor…
Standard Model Meets Gravity: Electroweak Symmetry Breaking and Inflation
Mikhail Shaposhnikov, Andrey Shkerin, Sebastian Zell
We propose a model for combining the Standard Model (SM) with gravity. It relies on a non-minimal coupling of the Higgs field to the Ricci scalar and on the Palatini formulation of…
Universe's Primordial Quantum Memories
Gia Dvali, Lukas Eisemann, Marco Michel +1
We provide a very general argument showing that the Universe must have kept its quantum memories from an epoch much earlier than e-foldings before the end of inflation. The po…
A Proof of the Axion?
Gia Dvali, Cesar Gomez, Sebastian Zell
We show that the de Sitter quantum breaking bound when applied to QCD exposes the necessity of the axion solution to the strong CP problem. The Peccei-Quinn mechanism emerges as a…
Discrete Symmetries Excluded by Quantum Breaking
Gia Dvali, Cesar Gomez, Sebastian Zell
In this note we show that the cosmological domain wall and the de Sitter quantum breaking problems complement each other in theories with discrete symmetries that are spontaneously…
Quantum Breaking Bound on de Sitter and Swampland
Gia Dvali, Cesar Gomez, Sebastian Zell
Quantum consistency suggests that any de Sitter patch that lasts a number of Hubble times that exceeds its Gibbons-Hawking entropy divided by the number of light particle species s…
The Scales of the Infrared
Cesar Gomez, Raoul Letschka, Sebastian Zell
In theories with long-range forces like QED or perturbative gravity, loop corrections lead to vanishing amplitudes. There are two well-known procedures to address these infrared di…
Infrared Divergences and Quantum Coherence
Cesar Gomez, Raoul Letschka, Sebastian Zell
In theories with long-range forces like QED or perturbative gravity, only rates that include emitted soft radiation are non-vanishing. Independently of detector resolution, finite…
Black Hole Evaporation, Quantum Hair and Supertranslations
Cesar Gomez, Sebastian Zell
In a black hole, hair and quantum information retrieval are interrelated phenomena. The existence of any new form of hair necessarily implies the existence of features in the quant…
Quantum Break-Time of de Sitter
Gia Dvali, Cesar Gomez, Sebastian Zell
The quantum break-time of a system is the time-scale after which its true quantum evolution departs from the classical mean field evolution. For capturing it, a quantum resolution…