We study the effects of explicit spacetime-symmetry breaking on primordial tensor
fluctuations using an effective-field theory for Lorentz/CPT violation. We find that the graviton …

We have discovered a class of dynamically stable coherent states for motion on the half line.
The regularization of the half line boundary and the consequent quantum motion are …

A quantum cosmological bouncing model may exhibit an ambiguity stemming from the
nonclassical nature of the background evolution: Two classically equivalent theories can …

By quantizing the background as well as the perturbations in a simple one fluid model, we
show that there exists an ambiguity in the choice of relevant variables (assuming factor …

We study a semiclassical model of the mixmaster universe. We first derive the quantum
model and then introduce its semiclassical approximation. We employ a general integral …

We propose a new method to investigate signatures of a quantum gravity phase in the
primordial state of cosmological perturbations. We formulate and study a quantum model of …

One of the standard approaches of incorporating the quantum gravity (QG) effects into the
semiclassical analysis is to adopt the notion of a quantum-corrected spacetime arising from …

We apply the Dirac procedure for constrained systems to the Arnowitt–Deser–Misner
formalism linearized around the Bianchi I universe. We discuss and employ basic concepts …

By quantizing the background as well as the perturbations in a simple one fluid
cosmological model, we show that there exists an ambiguity in the choice of relevant …

Both General Relativity and quantum theory have been studied for over a hundred years by
physicists, mathematicians and philosophers. Each of these theories has been extremely …