46 citations · 199 across the 8 of their papers we have counts for
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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…
Light Dark Photon Dark Matter from Inflation
Yuichiro Nakai, Ryo Namba, Ziwei Wang
We discuss the possibility of producing a light dark photon dark matter through a coupling between the dark photon field and the inflaton. The dark photon with a large wavelength i…
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…