46 citations · 199 across the 8 of their papers we have counts for
5 papers · 1 filter
Entanglement entropy of cosmological perturbations for S-brane Ekpyrosis
Suddhasattwa Brahma, Robert Brandenberger, Ziwei Wang
We calculate the entanglement entropy of scalar perturbations due to gravitational non-linearities present in any model of canonically-coupled, single-field ekpyrosis. Specifically…
Reheating after S-Brane Ekpyrosis
Robert Brandenberger, Keshav Dasgupta, Ziwei Wang
In recent work, two of us proposed a nonsingular Ekpyrotic cosmology making use of an S-brane which forms at the end of the phase of Ekpyrotic contraction. This S-Brane mediates a…
Ekpyrotic Cosmology with a Zero-Shear S-Brane
Robert Brandenberger, Ziwei Wang
In a recent paper we proposed a mechanism for a continuous transition between a contracting Ekpyrotic phase and the Standard Big Bang phase of expansion: the bounce is generated by…
Nonsingular Ekpyrotic Cosmology with a Nearly Scale-Invariant Spectrum of Cosmological Perturbations and Gravitational Waves
Robert Brandenberger, Ziwei Wang
We propose a mechanism borrowed from string theory which yields a non-singular transition from a phase of Ekpyrotic contraction to the expanding phase of Standard Big Bang cosmolog…
Eternal Inflation, Entropy Bounds and the Swampland
Ziwei Wang, Robert Brandenberger, Lavinia Heisenberg
It has been suggested that low energy effective field theories should satisfy given conditions in order to be successfully embedded into string theory. In the case of a single cano…