Browsing Astronomy and Astrophysics by Title
Now showing items 125-144 of 195
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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 ... -
On the superconformal index of Argyres–Douglas theories
(2016-01-08) -
Opto-mechanical design of a new cross dispersion unit for the CRIRES+ high resolution spectrograph for the VLT
(2014-01-01)© 2014 SPIE. CRIRES is one of the few IR (0.92-5.2 μm) high-resolution spectrographs in operation at the VLT since 2006. Despite good performance it suffers a limitation that significantly hampers its ability: a small ... -
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 ... -
The Parameterised Post-Newtonian Limit of Fourth-Order Theories of Gravity
We determine the full post-Newtonian limit of theories of gravity that extend general relativity by replacing the Ricci scalar, R, in the generating Lagrangian by some analytic function, f(R). We restrict ourselves to ... -
The partition function of ABJ theory
(2013-05) -
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, ... -
Phosphorus-bearing molecules in solar-type star forming regions: First PO detection
(Blackwell Publishing Inc., 2016-11-11) -
Photoevaporation obfuscates the distinction between wind and viscous angular momentum transport in protoplanetary discs
(2024-01-01)How protoplanetary discs evolve remains an unanswered question. Competing theories of viscosity and magnetohydrodynamic disc winds have been put forward as the drivers of angular momentum transport in protoplanetary discs. ... -
Photosynthesis Under a Red Sun: Predicting the absorption characteristics of an extraterrestrial light-harvesting antenna
(Oxford University Press (OUP), 2023)Here, we discuss the feasibility of photosynthesis on Earth-like rocky planets in close orbit around ultracool red dwarf stars. Stars of this type have very limited emission in the photosynthetically active region of the ... -
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, ... -
Post-Newtonian cosmological modelling
(2015-05-26) -
The Power of General Relativity
We study the cosmological and weak-field properties of theories of gravity derived by extending general relativity by means of a Lagrangian proportional to $R^{1+\delta}$. This scale-free extension reduces to general ... -
Properties of Black Hole Radiation From Tunnelling
We consider the space-time associated with the evaporation of a black hole by quantum mechanical tunnelling events. It is shown that the surface through which tunnelling occurs is distinct from the global event horizon, ... -
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 ...