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Alternative Cosmology Group Newsletter - January 2008
Posted April 7, 2008
Editor's Note: This newsletter covers papers from December,
2007, but from now on we are calling the newsletters by their
date of publication, making this the January, 2008 edition.
WMAP Non-Gaussianity, continued
One of the strongest predictions of the dominant, inflationary
Big Bang theory is that the radiation from the Cosmic Microwave
background (CMB) is distributed randomly across the sky. The
small fluctuations in intensity in this radiation should be
described by a Gaussian distribution, the standard distribution
of a random process. But for two years paper after paper has
found that these predictions are contradicted in many different
ways. The CMB locations are not Gaussian—there are too many
“hot” or “cold” zones, and the zones are not dispersed randomly
on the sky, but align in certain directions.
One response to this data has been to attempt to somehow
minimize the difference between theory and prediction, for
example by arguing that, except for one very big cold spot, the
rest of the sky is truly random. A new paper by Pave Naselsky et
al refutes that argument, showing that there are many hot and
cold spots and confirming that, on scales of 5- 10 degrees on
the sky, the CMB is clearly non-Gaussian.
In almost all fields of science, the clear contradiction of such
a key prediction of a theory would cause its rejection.
Unfortunately, this is not the process in current cosmology.
Instead, the reaction is to supplement a failed theory with new,
hypothetical entities to fit the new observations. The paper by
Yadav and Wandelt is an illustration of this tendency. They,
too, confirm that the CMB as mapped by the WMAP satellites, is
non-Gaussian. But from this they conclude, not that the
inflationary theory is wrong, but only that it is too simple and
that more “exotic theories” with “multiple scalar fields,
features in inflation potential, non-adiabatic fluctuations,
non-canonical kinetic terms, deviations from the Bunch-Davies
vacuum” will be needed.
The dominant cosmology thus continues its evolution to an
increasingly Rococo collection of unsupported hypothetical
entities, a theory with less and less predictive power.
The mystery of the WMAP cold spot
Authors: Pave D. Naselsky (1), Per Rex Christensen (1), Peter
Coles (2), Oleg Verkhodanov (3), Dmitry Novikov (4,5), Jaiseung
Kim (1) ((1) Niels Bohr Institute, Copenhagen, Denmark; (2)
School of Physics and Astronomy, Cardiff University, Wales,
United Kingdom; (3) Special astrophysical observatory, Nizhnij
Arkhyz, Russia; (4) Imperial College, London, United Kingdom;
(5) AstroSpace Center of Lebedev Physical Institute, Moscow,
Russia)
http://arxiv.org/abs/0712.1118v1
Detection of primordial non-Gaussianity (fNL) in the WMAP 3-year
data at above 99.5% confidence
Authors: Amit P. S. Yadav, Benjamin D. Wandelt
http://arxiv.org/abs/0712.1148v2
MOND Theory
One alternative to dark matter is Modified Newtonian Dynamics,
or MOND, a theory of gravitation that is different form both
Newtonian gravity and General Relativity. Moffat and Toth
present in a new paper an effort to derive the equations of MOND
from fundamental principles. They claim a good agreement between
the theory’s predictions and the rotation curves of galaxies.
Fundamental parameter-free solutions in Modified Gravity
Authors: J. W. Moffat, V. T. Toth
http://arxiv.org/abs/0712.1796v2
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