46 citations · 199 across the 8 of their papers we have counts for
8 papers
Sound Speed Resonance in the Gravitational Wave Background as a probe for non-standard early universe cosmologies
Igor de O. C. Pedreira, Amara Ilyas, Ziwei Wang +2
Gravitational waves constitute a powerful probe of the underlying theory of gravity. In extensions of general relativity, additional degrees of freedom, such as scalar fields in th…
Imprints of Dark Photons on Gravitational Wave Polarizations
Kimihiro Nomura, Jiro Soda, Kazushige Ueda +1
We study conversion processes between gravitons and dark photons and reveal the effects of dark photons on the polarization of gravitational waves. Considering cosmological dark ma…
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…