The debate continues in the
efforts used to come to grips with the apparent missing mass in the universe.
I suspect that the dark energy problem
goes away rather easily if that mass consists of low energy neutrinos which do
not provide gravitational potential. My
own theory of cloud cosmology posits such a regime modeled with my nth ordered
metrics hinted at in my paper introducing generalized cyclic functions.
We presently can only see high
energy neutrinos and do not predict any other type.
The first problem with measuring
neutrino mass is that it lacks a net gravitational potential. Thus any obvious mechanism with objects
providing any potential is in trouble.
It simply cannot be expected to react.
It really runs dark.
Dark-energy fingerprints found in ancient radiation
16:53 15 July 2011 by Kate McAlpine
Only cat burglars can match the stealth of dark
energy, credited with speeding up the universe's expansion over time, but
now its fingerprints have been glimpsed in the universe's oldest radiation.
The strongest
evidence for dark energy comes from supernovae, which suggest the
universe is expanding faster now than in the past. But the force should also
change the extent to which the cosmic
microwave background(CMB), relic radiation from the big bang, is warped, or
"lensed", by the gravity from distant galaxies and dark matter.
That's because the accelerating expansion of the universe should
prevent the growth of very massive structures. "In a universe with no dark
energy, massive objects would just keep growing, which results in more
gravitational lensing," says Sudeep Das of
the University of California , Berkeley
Gravitational lensing is tough to pick out in the ancient radiation
because the CMB contains random fluctuations. But Das and his colleagues have
used a new type of mathematical analysis to reveal for the first time the
distinctive distortions from gravitational lensing in the CMB.
Planck pending
The measurement, while not breaking any records for accuracy, bolsters
the case for dark energy. "Because of dark energy's importance to both the
future evolution of the universe and the foundation of physics, it is extremely
important to find a variety of evidence that confirms its existence," says
Stephen Boughn of
Haverford College in Pennsylvania, who was not involved in the work.
Das's observations of the CMB were made with the Atacama Cosmology
Telescope in Chile, but Europe 's Planck
satellite will soon return even more detailed measurements.
Applying the same mathematical technique to this Planck data could help
astronomers better understand other important problems in cosmology. One
outstanding question regards the mass of the neutrino, an elusive particle with
a mass so small that it has yet to register in any measurement.
Smooth operator
Nevertheless, neutrinos ought to interact with the universe's mass on
the largest scales: as these particles careen through the universe at near
light-speed, they interact with ordinary matter and tend to smooth out
variations in density. If the neutrinos are more massive, this effect is
stronger, but restricted to shorter distances. By contrast, near-massless
neutrinos aren't so forceful, but would show their effects over longer
distances.
Since gravitational lensing of the CMB gives a measure of matter's
tendency to clump together over a large range of distances, it can hint at the
strength and scale of the smoothing. And this, in turn, will allow cosmologists
to put a limit on the maximum possible mass of the neutrino.
Last year a team at University College London used the clustering of
galaxies as a proxy for the clumping of matter, and their result put that mass
at under 0.28 electronvolts, less than one-millionth the mass of an electron.
Gravitational lensing in the CMB could pin down the sum of the masses of
the three types of neutrino with even greater accuracy.
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