45 citations · 172 across the 9 of their papers we have counts for
6 papers · 1 filter
Kerr-NUT-de Sitter as an Inhomogeneous Non-Singular Bouncing Cosmology
Andres Anabalon, Sebastian F. Bramberger, Jean-Luc Lehners
We present exact non-singular bounce solutions of general relativity in the presence of a positive cosmological constant and an electromagnetic field, without any exotic matter. Th…
Non-Singular Bounces Catalysed by Dark Energy
Sebastian F. Bramberger, Jean-Luc Lehners
We investigate classically non-singular bounces caused by dark energy. In the presence of positive spatial curvature, vacuum energy, either in the form of a cosmological constant o…
Solving the flatness problem with an anisotropic instanton in Hořava-Lifshitz gravity
Sebastian F. Bramberger, Andrew Coates, João Magueijo +3
In Hořava-Lifshitz gravity a scaling isotropic in space but anisotropic in spacetime, often called anisotropic scaling with the dynamical critical exponent z=3, lies at the base of…
The Wavefunction of Anisotropic Inflationary Universes With No-Boundary Conditions
Sebastian F. Bramberger, Shane Farnsworth, Jean-Luc Lehners
We study the emergence of anisotropic (Bianchi IX) inflationary universes with no-boundary conditions in the path integral approach to quantum gravity. In contrast to previous work…
Quantum Transitions Through Cosmological Singularities
Sebastian F. Bramberger, Thomas Hertog, Jean-Luc Lehners +1
In a quantum theory of cosmology spacetime behaves classically only in limited patches of the configuration space on which the wave function of the universe is defined. Quantum tra…
Quantum tunneling from paths in complex time
Sebastian F. Bramberger, George Lavrelashvili, Jean-Luc Lehners
We study quantum mechanical tunneling using complex solutions of the classical field equations. Simple visualization techniques allow us to unify and generalize previous treatments…