## Search

Now showing items 1-10 of 30

#### PyTransport: A Python package for the calculation of inflationary correlation functions

(2016-09-05)

PyTransport constitutes a straightforward code written in C++ together with Python scripts which automatically edit, compile and run the C++ code as a Python module. It has been written for Unix-like systems (OS X and ...

#### The Method of Images in Cosmology

We apply the method of images to the exact initial data for cosmological models that contain a number of regularly arranged discrete masses. This allows us to join cosmological regions together by throats, and to construct ...

#### Piecewise Silence in Discrete Cosmological Models

We consider a family of cosmological models in which all mass is confined to a regular lattice of identical black holes. By exploiting the reflection symmetry about planes that bisect these lattices into identical halves, ...

#### On the Emergence of Accelerating Cosmic Expansion in f(R) Theories of Gravity

We consider cosmological modelling in $f(R)$ theories of gravity, using both top-down and bottom-up constructions. The top-down models are based on Robertson-Walker geometries, and the bottom-up constructions are built by ...

#### The Parameterised Post-Newtonian Limit of Bimetric Theories of Gravity

We consider the post-Newtonian limit of a general class of bimetric theories of gravity, in which both metrics are dynamical. The established parameterised post-Newtonian approach is followed as closely as possible, although ...

#### Hubble Diagram Dispersion From Large-Scale Structure

We consider the effects of large structures in the Universe on the Hubble diagram. This problem is treated non-linearly by considering a Swiss Cheese model of the Universe in which under-dense voids are represented as ...

#### Perturbation Theory in Lemaitre-Tolman-Bondi Cosmology

The Lemaitre-Tolman-Bondi solution has received much attention as a possible alternative to Dark Energy, as it is able to account for the apparent acceleration of the Universe without any exotic matter content. However, ...

#### FRW cosmology in Milgrom's bimetric theory of gravity

We consider spatially homogeneous and isotropic Friedmann-Robertson-Walker (FRW) solutions of Milgrom's recently proposed class of bimetric theories of gravity. These theories have two different regimes, corresponding to ...

#### Observational Constraints on the Completeness of Space near Astrophysical Objects

We consider the observational effects of a deficit angle, w, in the topology of the solar system and in the 'double pulsar' system PSR J0737-3039A/B. Using observations of the perihelion precession of Mercury, and the ...

#### Errors in Estimating Omega_Lambda due to the Fluid Approximation

The matter content of the Universe is strongly inhomogeneous on small scales. Motivated by this fact, we consider a model of the Universe that has regularly spaced discrete masses, rather than a continuous fluid. The optical ...