## Search

Now showing items 21-30 of 39

#### Cosmic acceleration from M theory on twisted spaces

(University of Canterbury. Physics and Astronomy, 2005)

In a recent paper [I. P. Neupane and D. L. Wiltshire, Phys. Lett. B 619, 201 (2005).] we have found a new class of accelerating cosmologies arising from a time-dependent compactification of classical supergravity on product ...

#### Cosmic clocks, cosmic variance and cosmic averages

(University of Canterbury. Physics and Astronomy, 2007)

Cosmic acceleration is explained quantitatively, purely in general
relativity with matter obeying the strong energy condition, as an apparent effect
due to quasilocal gravitational energy differences that arise in the ...

#### Hubble flow variance and the cosmic rest frame

(University of Canterbury. Physics and Astronomy, 2013)

We characterize the radial and angular variance of the Hubble flow in the composite sample of 4534 galaxies, on scales in which much of the flow is in the nonlinear regime. With no cosmological assumptions other than the ...

#### Operator ordering and consistency of the wavefunction of the Universe

(University of Canterbury. Physics and Astronomy, 1999)

We demonstrate in the context of the minisuperspace model consisting of a closed Friedmann-Robertson-Walker universe coupled to a scalar field that Vilenkin’s tunneling wavefunction can only
be consistently defined for ...

#### Future supernova probes of quintessence

(University of Canterbury. Physics and Astronomy, 2001)

We investigate the potential of a future supernovae data set, as might be obtained by the proposed SNAP satellite, to discriminate between two possible explanations for the observed dimming of the high redshift type IA ...

#### Dark energy from cosmic structure

(University of Canterbury. Physics and Astronomy, 2014)

Apparent cosmic acceleration can be understood by
treating geometry of universe more realistically
understanding fundamental aspects of general
relativity which have not been fully explored –
quasi–local gravitational ...

#### Gravitational energy as dark energy: Towards concordance cosmology without Lambda

(University of Canterbury. Physics and Astronomy, 2009)

I briefly outline a new physical interpretation to the average cosmological parameters for an inhomogeneous universe with backreaction. The variance in local geometry and gravitational energy between ideal isotropic observers ...

#### Wave functions for arbitrary operator ordering in the de Sitter minisuperspace approximation

(University of Canterbury. Physics and Astronomy, 2000)

We derive exact series solutions for the Wheeler-DeWitt equation corresponding
to a spatially closed Friedmann-Robertson-Walker universe with
cosmological constant for arbitrary operator ordering of the scale factor of ...

#### Supernova tests of the timescape cosmology

(University of Canterbury. Physics and Astronomy, 2011)

The timescape cosmology has been proposed as a viable alternative to homogeneous
cosmologies with dark energy. It realises cosmic acceleration as an apparent effect
that arises in calibrating average cosmological parameters ...

#### What is dust? - Physical foundations of the averaging problem in cosmology

(University of Canterbury. Physics and Astronomy, 2011)

The problems of coarse-graining and averaging of inhomogeneous
cosmologies, and their backreaction on average cosmic evolution, are reviewed from
a physical viewpoint. A particular focus is placed on comparing different ...