149 citations · 1k across the 32 of their papers we have counts for
33 papers
Detecting Axion-Like Particles With Coiled Optical Fibers I: Silica Fibers
Gia Dvali, Sebastian Zell, Tongxuan Zhang
We propose a new approach to axion-like particle (ALP) searches based on long, coiled optical fibers in an external magnetic field. We develop the theoretical framework required to…
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…
No Dark Matter Axion During Minimal Higgs Inflation
Claire Rigouzzo, Sebastian Zell
We study minimal versions of Higgs inflation in the presence of a massless QCD axion. While the inflationary energy scale of the metric variant is too high to accommodate isocurvat…
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…
Critical Points in Palatini Higgs Inflation with Small Non-Minimal Coupling
Arthur Poisson, Inar Timiryasov, Sebastian Zell
We investigate inflation driven by the Higgs boson in the Palatini formulation of General Relativity. Our analysis primarily focuses on a small non-minimal coupling of the Higgs fi…
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 the Standard Model and Dark Matter Fermions
Claire Rigouzzo, Sebastian Zell
General Relativity (GR) exists in different formulations, which are equivalent in pure gravity. Once matter is included, however, observable predictions generically depend on the v…
The Timescales of Quantum Breaking
Marco Michel, Sebastian Zell
Due to the inevitable existence of quantum effects, a classical description generically breaks down after a finite quantum break-time . We aim to find criteria for determining…
: A Program for Time Evolution With Improved Error Bound
Marco Michel, Sebastian Zell
We present , a program for computing time evolution in a generic quantum system. It relies on well-known Krylov subspace techniques to tackle the problem of multiplyin…
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…
Field redefinitions, perturbative unitarity and Higgs inflation
Georgios K. Karananas, Mikhail Shaposhnikov, Sebastian Zell
For inflation driven by the Higgs field coupled non-minimally to gravity, we study the cutoff energy scale above which perturbation theory breaks down. Employing the metric formula…
EuCAPT White Paper: Opportunities and Challenges for Theoretical Astroparticle Physics in the Next Decade
R. Alves Batista, M. A. Amin, G. Barenboim +134
Astroparticle physics is undergoing a profound transformation, due to a series of extraordinary new results, such as the discovery of high-energy cosmic neutrinos with IceCube, the…
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 Portal to Dark Matter
Mikhail Shaposhnikov, Andrey Shkerin, Inar Timiryasov +1
It is well-known since the works of Utiyama and Kibble that the gravitational force can be obtained by gauging the Poincaré group, which puts gravity on the same footing as the Sta…
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…
Higgs inflation in Einstein-Cartan gravity
Mikhail Shaposhnikov, Andrey Shkerin, Inar Timiryasov +1
We study inflation driven by the Higgs field in the Einstein-Cartan formulation of gravity. In this theory, the presence of the Holst and Nieh-Yan terms with the Higgs field non-mi…
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…
Quantum Effects in Palatini Higgs Inflation
Mikhail Shaposhnikov, Andrey Shkerin, Sebastian Zell
We study quantum effects in Higgs inflation in the Palatini formulation of gravity, in which the metric and connection are treated as independent variables. We exploit the fact tha…
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…