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Type of Document Dissertation Author Menzies-Gow, Dylan Author's Email Address dmenzies@nd.edu URN etd-07292006-145616 Title Tests of Non-Standard Cosmological Theories Degree Doctor of Philosophy Department Physics Advisory Committee
Advisor Name Title Don Howard Committee Chair Chris Kolda Committee Member Dinshaw Balsara Committee Member Grant J. Mathews Committee Member James J. Kolata Committee Member Keywords
- peculiar velocity
- dark matter
- topology
- microwave background
- rotation curves
- cosmology
- aberration
Date of Defense 2006-07-06 Availability unrestricted Abstract This dissertation investigates some propositions that fall outside the main-stream of the standard big bang cosmology. We begin with partial evidence from
the Cosmic Microwave Background (CMB) that the universe may be finite, com-
pactified and flat, or at least nearly flat. The simplest interpretation of a flat
universe is that it is infinite and non-compact. However, there are a great variety
of ways that infinite universes can be ‘wrapped up’ and given a compact finite vol-
ume, without the need to modify general relativity. Detailed analysis of the CMB
could potentially tell us the nature of the compactification, except that there is
considerable uncertainty over sources of error. Another approach is to correlate
the positions of distant luminous objects. While this cannot probe so broad a
set of possibilities, it may be more sensitive for those that it can. In this thesis
a new technique is developed that is much more sensitive to the very-nearly flat
cases than previous tests of this type. Application to existing catalogs rules out
a compact dimension smaller than 90% of the present horizon radius. The test
requires that the position of objects is corrected for relativistic aberration. This
gives rise to a second piece of work that systemizes corrections for objects and
also the microwave background.
The final part looks at an unusual explanation for galaxy rotation curves.
These are conventionally thought to be the result of a dark matter halo that
Dylan R Menzies-Gow
enshrowds each galaxy. Such dark matter also helps to account for the large
quantity dark matter deduced from observations of the CMB. However, it has
been suggested that the rotation curves could be a classical general relativistic
effect, despite the non-relativistic velocities and densities involved. Such a claim
is very unusual and has created considerable contraversy. The chapter presents
a conclusive analysis to demonstrate that the suggested model is unphysical by
implying an infinite mass for each galaxy.
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