Quantum transitions through cosmological singularities

Sebastian F. Bramberger, Thomas Hertog, Jean-Luc Lehners, Yannick Vreys
2017 Journal of Cosmology and Astroparticle Physics  
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 transitions can connect classical evolution in different patches. Working in the saddle point approximation and in minisuperspace we compute quantum transitions connecting inflationary histories across a de Sitter like throat or a singularity. This supplies probabilities for how an inflating universe, when evolved
more » ... ds, transitions and branches into an ensemble of histories on the opposite side of a quantum bounce. Generalising our analysis to scalar potentials with negative regions we identify saddle points describing a quantum transition between a classically contracting, crunching ekpyrotic phase and an inflationary universe.
doi:10.1088/1475-7516/2017/07/007 fatcat:yqjbatnz7vc3pdayn3kmxcqly4