45 citations · 172 across the 9 of their papers we have counts for
4 papers · 1 filter
Homogeneous Transitions during Inflation: a Description in Quantum Cosmology
Sebastian F. Bramberger, Alice Di Tucci, Jean-Luc Lehners
The usual description of inflationary fluctuations uses the framework of quantum field theory (QFT) in curved spacetime, in which quantum fluctuations are superimposed on a classic…
Aspects of the negative mode problem in quantum tunneling with gravity
Sebastian F. Bramberger, Mariam Chitishvili, George Lavrelashvili
Some solutions describing vacuum decay exhibit a catastrophic instability. This, so-called negative mode problem in quantum tunneling with gravity, was discovered 34 years ago and…
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…