111 citations · 244 across the 7 of their papers we have counts for
10 papers
Wormhole creation by quantum tunnelling
Lorenzo Battarra, George Lavrelashvili, Jean-Luc Lehners
We study the process of quantum tunnelling in self-interacting scalar field theories with non-minimal coupling to gravity. In these theories gravitational instantons can develop a…
Creation of wormholes by quantum tunnelling in modified gravity theories
Lorenzo Battarra, George Lavrelashvili, Jean-Luc Lehners
We study the process of quantum tunnelling in scalar-tensor theories in which the scalar field is non-minimally coupled to gravity. In these theories gravitational instantons can d…
On the No-Boundary Proposal for Ekpyrotic and Cyclic Cosmologies
Lorenzo Battarra, Jean-Luc Lehners
The no-boundary proposal provides a compelling theory for the initial conditions of our universe. We study the implications of such initial conditions for ekpyrotic and cyclic cosm…
On the Creation of the Universe via Ekpyrotic Instantons
Lorenzo Battarra, Jean-Luc Lehners
We present a new class of complex instantons in the context of ekpyrotic cosmological theories. These instantons, which satisfy the "no-boundary" boundary conditions, describe the…
Cosmological Perturbations Through a Non-Singular Ghost-Condensate/Galileon Bounce
Lorenzo Battarra, Michael Koehn, Jean-Luc Lehners +1
We study the propagation of super-horizon cosmological perturbations in a non-singular bounce spacetime. The model we consider combines a ghost condensate with a Galileon term in o…
On the Quantum-To-Classical Transition for Ekpyrotic Perturbations
Lorenzo Battarra, Jean-Luc Lehners
We examine the processes of quantum squeezing and decoherence of density perturbations produced during a slowly contracting ekpyrotic phase in which entropic perturbations are conv…