A ‘defect’ in spacetime may be one of the most curious findings of the data collected from the Wilkinson Anisotropy Probe. What WMAP gave us is the earliest image of the cosmos we have in our repertoire, showing temperature changes across the microwave background thought to be the aftereffect of the Big Bang. When Marcos Cruz (Instituto de Fisica de Cantabria) and colleagues found a cold spot in the data, they launched an investigation to determine what in heaven could be causing it.
A random fluctuation in the data? Possibly, but the Spanish and British team studying the cold spot think the odds on that are only about one percent. A cosmic defect would be quite a find, evidence of exotic phase transitions in the infant universe involving the breaking of symmetry between particles. A cooling universe would see a phase transition when quarks, for example, became distinct from electrons and neutrinos. A homely analogy is to a kitchen freezer, where the defects in ice cubes show how irregularly matter behaves when it undergoes phase change.
Neil Turok (Cambridge), a co-author on the study, explained how such defects should form in the 1990s, pointing out that some of them might be visible in the cosmos today. He describes phase changes this way:
“Imagine a large crowd of people with everyone standing. To any person in it, the crowd looks roughly the same in all directions. Now tell them all to lie down. People would tend to lie in the same direction as their neighbours, but over large distances the direction chosen would vary. In some places, people would be unable to decide which was the best direction to lie in: if everyone lies down pointing directly away from you, you are forced to stand. You are now a defect in the symmetry, a texture.”
A cosmic defect, of course, would have occurred at high temperatures and at enormous energy levels for the particles involved, providing useful indicators of fundamental particles and forces as the cosmos evolved. Turok notes that defects called ‘textures’ could have formed as particles separated from the earliest hot plasma. Turok calls a texture “…a three-dimensional object like a blob of energy,” but adds that “…within the blob the energy fields making up the texture are twisted up.”
Further studies will be required to confirm that what the team has found is indeed a texture, but other hypotheses — scattering of the CMB by large galaxy clusters, for example — are looking less likely. Thus a cold spot in the WMAP data, plausibly a defect in the structure of the vacuum, will surely be a hot topic in upcoming research. The paper is Cruz et al., “Feature in the Cosmic Background Radiation Consistent with a Cosmic Texture,” to be published today on Science Express (abstract).
Sorry, the grammarian in me stumbled on the following: “Neil Turok (Cambridge), a co-author on the study, explained how such defects should form in the 1990s,…” Wow! The defects formed that recently?
Tee hee.
Ha! Ryan, the next theory will have to explain the defects that formed in the 1980s… :-)
Why our time dimension is about to become space-like
October 9th, 2007 by KFC
It don’t get much weirder than this. The universe is about to lose its dimension of time says a group of theoretical astrobods at the University of Salamanca in Spain. And they got the evidence to prove it.
The idea comes from the study of braneworlds: the thinking that the universe we see around us is a 4-dimensional cosmos called a braneworld embedded in a multidimensional universe. The “signature” of our universe is the number of space and time-like dimensions it has: in our case we got 3 space-like dimensions and one time-like dimension. It’s what astrobods call a Lorentzian universe. So far so good: lots of astronutters think the same thing.
But our universe may not always have been like this. Some theorists think it may once have had a Euclidean signature meaning that all the dimensions were space-like. Now Marc “Bars” Mars and a few pals in Spain say that the Universe’s signature might be about to flip from Lorentzian to Euclidean. In other words, our dimension of time is about turn space-like. Gulp!
This ain’t entirely bonkers and here’s why. Bars Mars has calculated what it’s like to be an observer in a universe that is about to flip and get this: it would look as if it were expanding and accelerating away from us. Sound familiar?
Yep, it’s exactly what astrobods have been observin over the last few years, a phenomenon they attribute to dark energy. If Bars Mars is right, dark energy ain’t got nothing to do with it and we’re all starin’ down the barrel of a cosmic catastrophe.
Still, maybe four space-like dimensions will be better than three. Who needs time anyway?
Ref: arxiv.org/abs/0710.0820: Is the Accelerated Expansion Evidence of a Forthcoming change of Signature?
http://arxivblog.com/?p=71
The Shape and Topology of the Universe
Authors: Jean-Pierre Luminet
(Submitted on 15 Feb 2008)
Abstract: What is the shape of the Universe? Is it curved or flat, finite or infinite ? Is space “wrapped around” to create ghost images of faraway cosmic sources? We review how tessellations allow to build multiply-connected 3D Riemannian spaces useful for cosmology. We discuss more particularly the proposal of a finite, positively curved, dodecahedral space for explaining some puzzling features of the cosmic microwave background radiation, as revealed by the 2003-2006 WMAP data releases.
Comments: 21 pages, 11 figures. Proceedings of conference “Tessellations : The world a jigsaw”, Leyden (Netherlands), march 2006
Subjects: Astrophysics (astro-ph)
Cite as: arXiv:0802.2236v1 [astro-ph]
Submission history
From: Jean-Pierre Luminet [view email]
[v1] Fri, 15 Feb 2008 16:35:11 GMT (1391kb,D)
http://arxiv.org/abs/0802.2236
Hi ljk;
Assumming that the universe may be finite, positively curved, and dodecahedral is shape with multiple connectedness, perhaps there are still a near infinite ever growing set of such universes in the form of parallel histories such as those conjectured to exist in the “Many Worlds Interpretation” of quantum mechanics. Perhaps each act of a collapse of a wave function such as an act of decoherence leads to another entire parallel history which presumably could have its own ensemble of wave function collapses thus leading to all the more parallel histories production.
Some theorists would say that such histories are only convienient mathematical abstractions however, certain forms of quantum computers would, in essense, require the actual existence of such histories in order to function.
What’s more, there is no reason to think that there might not be other: shapes, sizes, degreed of multiple connectednesses, types of and degreed of curvature; universes that lie seperated from our universe and any parallel histories in abstract physical space. Perhaps there still exist space of unlimited infinite extent and of unlimited infinite numbers of dimensions. Perhaps such infinite space is multiplied infinitely many times by paralell abstract real physical spaces.
What if our universe is simply a huge crystal of some form of exotic material that exhibits dodecahedral symmetry: a sort of world within a world within a world concept.
Thanks;
Jim
Goodness in the Axis of Evil
Authors: Rudolph E. Schild, Carl H. Gibson
(Submitted on 21 Feb 2008)
Abstract: An unexpected alignment of 2-4-8-16 cosmic microwave background spherical harmonic directions with the direction of a surprisingly large WMAP temperature minimum, a large radio galaxy void, and an unexpected alignment and handedness of galaxy spins have been observed. The alignments point to RA=202 degrees, delta = 25 degrees and are termed the “Axis of Evil”. Already many authors have commented about how the AE impacts our understanding of how structure emerged in the Universe within the framework of Lamda-CDM, warm dark matter, string theory, and hydro-gravitational dynamics (HGD). The latter uniquely predicts the size scales of the voids and matter condensations, based upon estimates of fluid forces in the early phases of structure formation. Reported departures from simple Gaussian properties of the WMAP data favor two regimes of turbulent structure formation, and from these we make predictions of the nature of finer structure expected to be measured with the PLANCK spacecraft.
From HGD, friction has limited the expansion of superclusters to 30 Mpc but supervoids have expanded with the universe to 300 Mpc.
Comments: 9 pages, 1 figure and 1 table, submitted to ApJ Letters
Subjects: Astrophysics (astro-ph)
Cite as: arXiv:0802.3229v1 [astro-ph]
Submission history
From: Rudolph E. Schild [view email]
[v1] Thu, 21 Feb 2008 22:24:00 GMT (626kb)
http://arxiv.org/abs/0802.3229
WMAP REVEALS NEUTRINOS, END OF DARK AGES, FIRST SECOND OF UNIVERSE
WASHINGTON – NASA released this week five years of data collected by
the Wilkinson Microwave Anisotropy Probe (WMAP) that refines our
understanding of the universe and its development. It is a treasure
trove of information, including at least three major findings:
• New evidence that a sea of cosmic neutrinos permeates the universe
• Clear evidence the first stars took more than a half-billion years
to create a cosmic fog
• Tight new constraints on the burst of expansion in the universe’s
first trillionth of a second
“We are living in an extraordinary time,” said Gary Hinshaw of NASA’s
Goddard Space Flight Center in Greenbelt, Md. “Ours is the first
generation in human history to make such detailed and far-reaching
measurements of our universe.”
WMAP measures a remnant of the early universe – its oldest light. The
conditions of the early times are imprinted on this light. It is the
result of what happened earlier, and a backlight for the later
development of the universe. This light lost energy as the universe
expanded over 13.7 billion years, so WMAP now sees the light as
microwaves. By making accurate measurements of microwave patterns,
WMAP has answered many longstanding questions about the universe’s
age, composition and development.
The universe is awash in a sea of cosmic neutrinos. These almost
weightless sub-atomic particles zip around at nearly the speed of
light. Millions of cosmic neutrinos pass through you every second.
“A block of lead the size of our entire solar system wouldn’t even
come close to stopping a cosmic neutrino,” said science team member
Eiichiro Komatsu of the University of Texas at Austin.
WMAP has found evidence for this so-called “cosmic neutrino
background” from the early universe. Neutrinos made up a much larger
part of the early universe than they do today.
Microwave light seen by WMAP from when the universe was only 380,000
years old, shows that, at the time, neutrinos made up 10% of the
universe, atoms 12%, dark matter 63%, photons 15%, and dark energy was
negligible. In contrast, estimates from WMAP data show the current
universe consists of 4.6% percent atoms, 23% dark matter, 72% dark
energy and less than 1 percent neutrinos.
Cosmic neutrinos existed in such huge numbers they affected the
universe’s early development. That, in turn, influenced the microwaves
that WMAP observes. WMAP data suggest, with greater than 99.5%
confidence, the existence of the cosmic neutrino background – the
first time this evidence has been gleaned from the cosmic microwaves.
Much of what WMAP reveals about the universe is because of the
patterns in its sky maps. The patterns arise from sound waves in the
early universe. As with the sound from a plucked guitar string, there
is a primary note and a series of harmonics, or overtones. The third
overtone, now clearly captured by WMAP, helps to provide the evidence
for the neutrinos.
The hot and dense young universe was a nuclear reactor that produced
helium. Theories based on the amount of helium seen today predict a
sea of neutrinos should have been present when helium was made. The
new WMAP data agree with that prediction, along with precise
measurements of neutrino properties made by Earth-bound particle
colliders.
Another breakthrough derived from WMAP data is clear evidence the
first stars took more than a half-billion years to create a cosmic
fog. The data provide crucial new insights into the end of the “dark
ages,” when the first generation of stars began to shine. The glow
from these stars created a thin fog of electrons in the surrounding
gas that scatters microwaves, in much the same way fog scatters the
beams from a car’s headlights.
“We now have evidence that the creation of this fog was a drawn-out
process, starting when the universe was about 400 million years old
and lasting for half a billion years,” said WMAP team member Joanna
Dunkley of the University of Oxford in the U.K. and Princeton
University in Princeton, N.J. “These measurements are currently
possible only with WMAP.”
A third major finding arising from the new WMAP data places tight
constraints on the astonishing burst of growth in the first trillionth
of a second of the universe, called “inflation”, when ripples in the
very fabric of space may have been created. Some versions of the
inflation theory now are eliminated. Others have picked up new
support.
“The new WMAP data rule out many mainstream ideas that seek to
describe the growth burst in the early universe,” said WMAP principal
investigator, Charles Bennett, of The Johns Hopkins University in
Baltimore, Md. “It is astonishing that bold predictions of events in
the first moments of the universe now can be confronted with solid
measurements.”
The five-year WMAP data were released this week, and results were
issued in a set of seven scientific papers submitted to the
Astrophysical Journal. For further information, see
http://wmap.gsfc.nasa.gov.
Prior to the release of the new five-year data, WMAP already had made
a pair of landmark finds. In 2003, the probe’s determination that
there is a large percentage of dark energy in the universe erased
remaining doubts about dark energy’s very existence. That same year,
WMAP also pinpointed the 13.7 billion year age of the universe.
Additional WMAP science team institutions are: the Canadian Institute
for Theoretical Astrophysics, Columbia University, University of
British Columbia, ADNET Systems, University of Chicago, Brown
University, and UCLA.
For related images to this story, please visit on the Web:
http://www.nasa.gov/topics/universe/features/wmap_five.html
Is the CMB Cold Spot a gate to extra dimensions?
Authors: J.A.R. Cembranos, A. de la Cruz-Dombriz, A. Dobado, A.L. Maroto
(Submitted on 5 Mar 2008)
Abstract: One of the most striking features found in the cosmic microwave background data is the presence of an anomalous Cold Spot (CS) in the temperature maps made by the Wilkinson Microwave Anisotropy Probe (WMAP). This CS has been interpreted as the result of the presence of a collapsing texture, perhaps coming from some early universe Grand Unified Theory (GUT) phase transition.
In this work we propose an alternative explanation based on a completely different kind of texture which appears in a natural way in a broad class of brane-world models. This type of textures known as brane-skyrmions can be understood as holes in the brane which make possible to pass through them along the extra-dimensional space. The typical scales needed for the proposed brane-skyrmions to correctly describe the observed CS can be as low as the electroweak scale.
Comments: 4 pages
Subjects: Astrophysics (astro-ph); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics – Phenomenology (hep-ph)
Report number: FTPI-MINN-08/09, UMN-TH-2640/08
Cite as: arXiv:0803.0694v1 [astro-ph]
Submission history
From: Antonio Lopez Maroto [view email]
[v1] Wed, 5 Mar 2008 16:23:55 GMT (9kb)
http://arxiv.org/abs/0803.0694
Doughnut-shaped Universe: Astronomers say Universe is small
and finite
Nature May 23, 2008
Ulm University scientists have
found evidence suggesting that the
Universe is small and finite, and
shaped like a 3-torus (doughnut).
They used three techniques to
compare predictions of how the
cosmic microwave background’s
temperature fluctuations in
different areas of the sky should
match up in both an infinite
Universe and a doughnut one….
http://www.kurzweilai.net/email/newsRedirect.html?newsID=8758&m=25748
A full sky, low foreground, high resolution CMB map from WMAP
Authors: J. Delabrouille, J.-F. Cardoso, M. Le Jeune, M. Betoule, G. Fay, F. Guilloux
(Submitted on 4 Jul 2008)
Abstract: The WMAP satellite has made available high quality maps of the sky in five frequency bands ranging from 22 to 94 GHz, with the main scientific objective of studying the anisotropies of the Cosmic Microwave Background (CMB). These maps, however, contain a mixture of emissions from various astrophysical origins, superimposed on CMB emission.
The objective of the present work is to make a high resolution CMB map in which contamination by such galactic and extra-galactic foregrounds, as well as by instrumental noise, is as low as possible. The method used is an implementation of a constrained linear combination of the channels with minimum error variance, and of Wiener filtering, on a frame of spherical wavelets called needlets, allowing localised filtering in both pixel space and harmonic space. We obtain a low contamination low noise CMB map at the resolution of the WMAP W channel, which can be used for a range of scientific studies. We obtain also a Wiener-filtered version with minimal integrated error.
The resulting CMB maps offer significantly better rejection of galactic foregrounds than previous CMB maps from WMAP data. They can be considered as the most precise full-sky CMB temperature maps to-date.
Comments: Submitted to A&A, 24 pages, 15 figures. For pdf file with full resolution figures, and for data products, see this http URL
Subjects: Astrophysics (astro-ph)
Cite as: arXiv:0807.0773v1 [astro-ph]
Submission history
From: Jacques Delabrouille [view email]
[v1] Fri, 4 Jul 2008 15:01:39 GMT (786kb,D)
http://arxiv.org/abs/0807.0773
Pulsars as the Source of the WMAP Haze
Authors: Manoj Kaplinghat, Daniel J. Phalen, Kathryn M. Zurek
(Submitted on 5 May 2009 (v1), last revised 9 Sep 2009 (this version, v2))
Abstract: The WMAP haze is an excess in the 22 to 93 GHz frequency bands of WMAP extending about 10 degrees from the galactic center. We show that synchrotron emission from electron-positron pairs injected into the interstellar medium by the galactic population of pulsars with energies in the 1 to 100 GeV range can explain the frequency spectrum of the WMAP haze and the drop in the average haze power with latitude.
The same spectrum of high energy electron-positron pairs from pulsars, which gives rise to the haze, may also generate the observed excesses in AMS, HEAT and PAMELA.
We discuss the spatial morphology of the pulsar synchrotron signal and its deviation from spherical symmetry, which may provide an avenue to determine the pulsar contribution to the haze.
Comments: 18 pages, 4 figures. Corrected errors in fig 1-3 and added discussion of the detailed spatial morphology of the haze signal
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics – Phenomenology (hep-ph)
Report number: MCTP-09-12
Cite as: arXiv:0905.0487v2 [astro-ph.HE]
Submission history
From: Daniel Phalen [view email]
[v1] Tue, 5 May 2009 18:44:57 GMT (27kb)
[v2] Wed, 9 Sep 2009 14:39:29 GMT (221kb)
http://arxiv.org/abs/0905.0487
September 16, 2009
What! No Parallel Universe? Cosmic Cold Spot Just Data Artifact
Written by Nancy Atkinson
Rats! Another perplexing space mystery solved by science. New analysis of the famous “cold spot” in the cosmic microwave background reveals, and confirms, actually, that the spot is just an artifact of the statistical methods used to find it.
That means there is no supervoid lurking in the CMB, and no parallel universe lying just beyond the edge of our own. What fun is that?
Back in 2004, astronomers studying data from the Wilkinson Microwave Anisotropy Probe (WMAP) found a region of the cosmic microwave background in the southern hemisphere in the direction of the constellation of Eridanus that was significantly colder than the rest by about 70 microkelvin. The probability of finding something like that was extremely low.
If the Universe really is homogeneous and isotropic, then all points in space ought to experience the same physical development, and appear the same. This just wasn’t supposed to be there.
Some astronomers suggested the spot could be a supervoid, a remnant of an early phase transition in the universe. Others theorized it was a window into a parallel universe.
Well, it turns out, it wasn’t there.
Full article here:
http://www.universetoday.com/2009/09/16/what-no-parallel-universe-cosmic-cold-spot-just-data-artifact/
NASA’S WMAP Project Completes Satellite Operations Mission Observed Universe’s Oldest Light
http://www.spaceref.com/news/viewpr.html?pid=31790
“After nine years of scanning the sky, the Wilkinson Microwave Anisotropy Probe (WMAP) space mission has concluded its observations of the cosmic microwave background, the oldest light in the universe. The spacecraft has not only given scientists their best look at this remnant glow, but also established the scientific model that describes the history and structure of the universe.”