827 citations · 16k across the 208 of their papers we have counts for
12 papers · 1 filter
Cosmology and the Origin of Life
John D. Barrow
We discuss some of the cosmological constraints on the evolution and persistence of life in the Universe and in hypothetical universes other than our own. We highlight the role pla…
Varying- Theories and Solutions to the Cosmological Problems
John D. Barrow, Joao Magueijo
If the fine structure constant were to change, then a number of interpretations would be possible, attributing this change either to variations in the electron ch…
Cosmologies with Varying Light-Speed
John D. Barrow
We analyse a generalisation of general relativity that incorporates a cosmic time-variation of the velocity of light in vacuum, and the Newtonian gravitation 'constant', …
Solutions to the Quasi-flatness and Quasi-lambda Problems
John D. Barrow, Joao Magueijo
Big Bang models of the Universe predict rapid domination by curvature, a paradox known as the flatness problem. Solutions to this problem usually leave the Universe exactly flat fo…
Anisotropic stresses in inhomogeneous universes
John Barrow, Roy Maartens
Anisotropic stress contributions to the gravitational field can arise from magnetic fields, collisionless relativistic particles, hydrodynamic shear viscosity, gravitational waves,…
How the Universe got its Spots
Janna Levin, Evan Scannapieco, Giancarlo de Gasperis +2
The universe displays a three-dimensional pattern of hot and cold spots in the radiation remnant from the big bang. The global geometry of the universe can be revealed in the spati…
String Cosmology and Chaos
John D. Barrow, Mariusz P. Dabrowski
We investigate Bianchi type IX ''Mixmaster'' universes within the framework of the low-energy tree-level effective action for string theory, which (when the ''stringy'' 2-form axio…
Godel Universes in String Theory
John D. Barrow, Mariusz P. Dabrowski
We show that homogeneous Gödel spacetimes need not contain closed timelike curves in low-energy-effective string theories. We find exact solutions for the Gödel metric in string th…
Microwave Background Signals from Tangled Magnetic Fields
Kandaswamy Subramanian, John D. Barrow
An inhomogeneous cosmological magnetic field will create Alfven-wave modes that induce a small rotational velocity perturbation on the last scattering surface of the microwave back…
Gauge-invariant magnetic perturbations in perfect-fluid cosmologies
Christos G. Tsagas, John D. Barrow
We develop further our extension of the Ellis-Bruni covariant and gauge-invariant formalism to the general relativistic treatment of density perturbations in the presence of cosmol…
A Search for Time Variation of the Fine Structure Constant
John K. Webb, Victor V. Flambaum, Christopher W. Churchill +2
A method offering an order of magnitude sensitivity gain is described for using quasar spectra to investigate possible time or space variation in the fine structure constant, alpha…
The radiation-matter transition in Jordan-Brans-Dicke theory
Andrew R Liddle, Anupam Mazumdar, John D Barrow
We study the transition from radiation domination to matter domination in Jordan-Brans-Dicke theory, in particular examining how the Hubble length at equality depends on the coupli…