48 citations · 232 across the 11 of their papers we have counts for
11 papers
Global gravitational instability of FLRW backgrounds - interpreting the dark sectors
Xavier Roy, Thomas Buchert, Sante Carloni +1
The standard model of cosmology is based on homogeneous-isotropic solutions of Einstein's equations. These solutions are known to be gravitationally unstable to local inhomogeneous…
Effective Inhomogeneous Cosmologies and Emerging Scalar Fields
Thomas Buchert, Nathaniel Obadia, Xavier Roy
In this contribution we summarize two recent applications of a correspondence between backreaction terms in averaged inhomogeneous cosmologies and an effective scalar field (the `m…
Effective inhomogeneous inflation: curvature inhomogeneities of the Einstein vacuum
Thomas Buchert, Nathaniel Obadia
We consider spatially averaged inhomogeneous universe models and argue that, already in the absence of sources, an effective scalar field arises through foliating and spatially ave…
Why does the Unruh effect rely on Lorentz invariance, while Hawking radiation does not ?
David Campo, Nathaniel Obadia
We show that without Lorentz invariance, the Unruh effect does not exist. We use modified dispersion relations and describe in turn: the non-thermal nature of the vacuum (defined i…
How hot are expanding universes ?
Nathaniel Obadia
A way to address the conundrum of Quantum Gravity is to illustrate the potentially fundamental interplay between quantum field theory, curved space-times physics and thermodynamics…
Unruh Effect for General Trajectories
N. Obadia, M. Milgrom
We consider two-level detectors coupled to a scalar field and moving on arbitrary trajectories in Minkowski space-time. We first derive a generic expression for the response functi…