123 citations · 659 across the 33 of their papers we have counts for
21 papers · 1 filter
QCD axion from broken scale symmetry
Georgios K. Karananas, Mikhail Shaposhnikov
A consistent non-compact axion cosmology requires a non-periodic field, an effective field theory valid sufficiently above the inflationary scale, and a small non-QCD contribution…
Three-form lifting of dilaton flat direction without and with gravity
Georgios K. Karananas
Spontaneous scale symmetry breaking is commonly associated with a flat direction in the action. We show that this need not be so if the dilaton is coupled to a three-form field in…
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…
The particle spectra of parity-violating theories: A less radical approach and an upgrade of PSALTer
Will Barker, Georgios K. Karananas, Haochen Tu
Due to computational barriers, the effects of parity violation have so far been grossly neglected in gravitational model-building, leading to a serious gap in the space of prior mo…
The particle content of (scalar curvature) metric-affine gravity
Georgios K. Karananas
Linearizing metric-affine~(scalar curvature) gravity -- an ``umbrella'' theory that includes as special cases the metrical, Einstein-Cartan, and Weyl quadratic models -- on top…
The particle content of gravity revisited
Georgios K. Karananas
Studying the spectrum of (pure) gravity on Minkowski background inevitably results into a Catch-22: any consistent interpretation of its particle dynamics dictates that no ac…
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…
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…
More on the operator-state map in non-relativistic CFTs
Georgios K. Karananas, Alexander Monin
We propose an algebraic construction of the operator-state correspondence in non-relativistic conformal field theories by explicitly constructing an automorphism of the Schrödinger…
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…
Islands in Linear Dilaton Black Holes
Georgios K. Karananas, Alex Kehagias, John Taskas
We derive a novel four-dimensional black hole with planar horizon that asymptotes to the linear dilaton background. The usual growth of its entanglement entropy before Page's time…
Aspects of spontaneous breaking of conformal invariance in the Fishnet CFT
Georgios K. Karananas
I will discuss spontaneous conformal symmetry breaking in the strongly -deformed limit of the supersymmetric Yang-Mills theory known as~\emph{Fishnet Conformal Fi…
Spontaneous Conformal Symmetry Breaking in Fishnet CFT
Georgios K. Karananas, Vladimir Kazakov, Mikhail Shaposhnikov
Quantum field theories with exact but spontaneously broken conformal invariance have an intriguing feature: their vacuum energy (cosmological constant) is equal to zero. Up to now,…
On the strong-CP problem and its axion solution in torsionful theories
Georgios K. Karananas
Gravitational effects may interfere with the axion solution to the strong-CP problem. We point out that gravity can potentially provide a protection mechanism against itself, in th…
CFT data and spontaneously broken conformal invariance
Georgios K. Karananas, Mikhail Shaposhnikov
We derive consistency conditions for the CFT data, which systems with exact but spontaneously broken conformal invariance must satisfy.
Poincaré, Scale and Conformal Symmetries: Gauge Perspective and Cosmological Ramifications
Georgios K. Karananas
In the first part of the thesis we focus on local symmetries. We review a self-consistent framework that we employed in order to discuss the dynamics of the theories of interest. I…
Scale invariant alternatives to general relativity. II. Dilaton properties
Georgios K. Karananas, Mikhail Shaposhnikov
In the present paper, we revisit gravitational theories which are invariant under TDiffs -- transverse (volume preserving) diffeomorphisms and global scale transformations. It is k…
Gauging nonrelativistic field theories using the coset construction
Georgios K. Karananas, Alexander Monin
We discuss how nonrelativistic spacetime symmetries can be gauged in the context of the coset construction. We consider theories invariant under the centrally extended Galilei alge…
Weyl vs. Conformal
Georgios K. Karananas, Alexander Monin
In this note we show that given a conformally invariant theory in flat space-time, it is not always possible to couple it to gravity in a Weyl invariant way.
Weyl and Ricci gauging from the coset construction
Georgios K. Karananas, Alexander Monin
In this paper we demonstrate how, using the coset construction, a theory can be systematically made Weyl invariant by gauging the scale symmetry. We show that an analog of the inve…