106 citations · 801 across the 31 of their papers we have counts for
8 papers · 1 filter
Before the Bang: Wormholes at the Dawn of the Universe
Panos Betzios, Paul Ghiringhelli, Ioannis D. Gialamas +1
This essay discusses recent progress on Euclidean wormholes as candidate contributions to the Universe's initial quantum state. The comparison with the Hartle-Hawking no-boundary p…
A Menagerie of Wormholes and Cosmologies in the Gravitational Path Integral
Panos Betzios, Paul Ghiringhelli, Ioannis D. Gialamas +1
We analyse a variety of Euclidean saddles in the gravitational path integral, with asymptotic AdS boundary conditions, in a class of Einstein-Scalar-Maxwell models. These include s…
Toward a gravitational network: Bridging metric-affine gravity and no-scale supergravity
Ioannis D. Gialamas, Theodoros Katsoulas, Kyriakos Tamvakis
We consider a class of models in the framework of metric-affine gravity and establish their correspondence to the bosonic sector of a class of no-scale supergravity models. The exc…
Dynamically induced spin-2 mass in a Weyl-invariant framework
Ioannis D. Gialamas, Kyriakos Tamvakis
We combine the ghost-free bimetric theory of gravity with the concept of local Weyl invariance, realized in the framework of Einstein-Cartan gravity. The gravitational sector, char…
Magnetic Anti-de Sitter Wormholes as seeds for Higgs Inflation
Panos Betzios, Ioannis D. Gialamas, Olga Papadoulaki
We show how certain types of magnetic asymptotically Anti-de Sitter Euclidean wormholes can catalyze the onset of inflation. These wormholes can be embedded as saddle point solutio…
Electroweak vacuum decay in metric-affine gravity
Ioannis D. Gialamas, Hardi Veermäe
We investigate the stability of the electroweak vacuum in metric-affine gravity in which the Standard Model Higgs boson can be non-minimally coupled to both the Ricci scalar and th…
A simple deformation of Starobinsky inflationary model
Dhimiter D. Canko, Ioannis D. Gialamas, George P. Kodaxis
We study a model including a real scalar field non-minimally coupled to gravity, which is conformally equivalent to an Einstein-Hilbert theory, involving two real…
On the Catalysis of the Electroweak Vacuum Decay by Black Holes at High Temperature
D. Canko, I. Gialamas, G. Jelic-Cizmek +2
We study the effect of primordial black holes on the classical rate of nucleation of AdS regions within the standard electroweak vacuum at high temperature. We find that the energy…