783 research outputs found
A Critique of Supernova Data Analysis in Cosmology
Observational astronomy has shown significant growth over the last decade and
has made important contributions to cosmology. A major paradigm shift in
cosmology was brought about by observations of Type Ia supernovae. The notion
that the universe is accelerating has led to several theoretical challenges.
Unfortunately, although high quality supernovae data-sets are being produced,
their statistical analysis leaves much to be desired. Instead of using the data
to directly test the model, several studies seem to concentrate on assuming the
model to be correct and limiting themselves to estimating model parameters and
internal errors. As shown here, the important purpose of testing a cosmological
theory is thereby vitiated.Comment: v2: Revised, comments and references added; Published version
[vailable at http://www.raa-journal.org/raa/index.php/raa/article/view/539
A Radical Departure from the ''steady State'' Concept in Cosmology
Radical departure from steady state theory in cosmolog
Mach's principle
The underlying idea in Mach's principle is that the origin of inertia or mass of a particle is a dynamical quantity determined by the environment, in particular the rest of the matter in the universe. In this article, we discuss the role of this idea in the Brans{Dicke theory of gravitation and the Hoyle Narlikar cosmology
Biscalar and bivector Green's functions in de Sitter space time
Biscalar and bivector Green's functions of wave equations are calculated explicitly in de Sitter space time. The calculation is performed by considering the electromagnetic field generated by the spontaneous creation of an electric charge
The lighter side of gravity: How Swami Gurutwananda received enlightenment?
This article does not have an abstract
Cosmology: past, present and future
This is a broad-brush review of the development of cosmology during the twentieth century. The 'past' deals with the first nine decades of the century while the 'present' deals with the last decade. Although technological achievements have helped the astronomer in better viewing the universe, a 'final' understanding still eludes the search for the correct cosmological model. The article ends with a list of unsolved questions which the 'future' may eventually answer
Einstein's legacy: relativistic cosmology
This review gives a historical account of how cosmology has developed since the 1917 paper of Albert Einstein. Today it is a frontier level science drawing on contemporary astronomy as well as contemporary physics, stretching both as far as extrapolations will permit. Thanks to numerous observations at different wavelengths, cosmologists today have their plates full. Extrapolations of laboratory tested physics are called for to understand all information within the framework of a standard model. The success and shortcomings of this approach are briefly discussed against the historical backdrop
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