Evidence for cosmic inflation wanes | Science/AAAS | News

Evidence for cosmic inflation wanes | Science/AAAS | News: Now, researchers from the European Space Agency's Planck spacecraft have shown that radiation from dust in our galaxy accounts for some, and possibly all, of the BICEP signal.

Backlash to Big Bang Discovery Gathers Steam - Scientific American

Backlash to Big Bang Discovery Gathers Steam - Scientific American: Spergel also says the BICEP2 team evidently failed to factor in contamination from the cosmic infrared background radiation that comes from distant, dusty galaxies. “When you do that,” Spergel says, “it’s probably enough to account for the entire signal they’re seeing.

Blockbuster Big Bang Result May Fizzle, Rumor Suggests | Science/AAAS | News

Blockbuster Big Bang Result May Fizzle, Rumor Suggests | Science/AAAS | News: To subtract the galactic foreground, BICEP researchers relied on a particular map of it generated by the European Space Agency's spacecraft Planck, which mapped the CMB across the entire sky from 2009 until last year. However, the BICEP team apparently interpreted the map as showing only the galactic emissions. In reality, it may also contain the largely unpolarized hazy glow from other galaxies, which has the effect of making the galactic microwaves coming from any particular point of the sky look less thoroughly polarized than they actually are. So using the map to strip out the galactic foreground may actually leave some of that foreground in the data where it could produce a spurious signal, Falkowski explains.

Cosmologists cast doubt on inflation evidence

Cosmologists cast doubt on inflation evidence: Inflation may very well be the cause—and Dent and company state right off the bat that "there is little doubt that inflation at the Grand Unified Scale is the best motivated source of such primordial waves" –  but there's also a possibility, however remote, that some other, later cosmic event is responsible for at least some if not all of the BICEP2 measurements.

Cosmologists Say Last Week’s Announcement About Gravitational Waves and Inflation May Be Wrong — The Physics arXiv Blog — Medium

Cosmologists Say Last Week’s Announcement About Gravitational Waves and Inflation May Be Wrong — The Physics arXiv Blog — Medium: Many cosmologists think that the same kind of phases changes occurred in the universe after inflation. Each phase change began in different regions at slightly different times...

This self-ordering process would have been hugely violent, generating its own gravitational waves that rippled through spacetime, albeit after inflation. Could this process be responsible for the polarisation that the BICEP2 team has measured?...

...a small improvement in the data could firmly rule out self-ordering as the origin of the signal.

First glimpse of big bang ripples from universe's birth - physics-math - 17 March 2014 - New Scientist

First glimpse of big bang ripples from universe's birth - physics-math - 17 March 2014 - New Scientist: Inflation should have stretched the very first gravitational waves created during the big bang, taking them from imperceptible wavelengths to a size we can detect in the CMB... Rippling gravitational waves would subtly change the polarisation pattern, twisting the CMB into distinctive swirls called B-modes...

"We see a big excess of power, and it looks exactly like the gravitational wave signal that we had been seeking," says Pryke. "There's a huge zoo of inflationary models, but if we look at the simplest ones, they would predict values in the ballpark that we're seeing..."

"If gravity were not quantised, inflation would not produce gravitational waves," says Guth.

Why I Still Doubt Inflation, in Spite of Gravitational Wave Findings | Cross-Check, Scientific American Blog Network

Why I Still Doubt Inflation, in Spite of Gravitational Wave Findings | Cross-Check, Scientific American Blog Network: ...inflation comes in so many different versions that it can give you “anything you want.” In other words, it cannot be falsified...

But here is what I’d like to see: First, corroboration of the BICEP2 findings by other groups and observatories. Second, experiments from high-energy physics that provide some sort of corroborating evidence of the driving mechanism of inflation. Third, an explanation of why the Alice’s Restaurant Problem isn’t still a problem. Fourth, an explanation of why only inflation, and not other more conventional physical phenomena, can account for the gravity-wave findings...

Did a hyper-black hole spawn the Universe? : Nature News & Comment

Did a hyper-black hole spawn the Universe? : Nature News : ...in the bulk universe the event horizon of a 4D black hole would be a 3D object — a shape called a hypersphere. When Afshordi’s team modeled the death of a 4D star, they found that the ejected material would form a 3D brane surrounding that 3D event horizon, and slowly expand.


The authors postulate that the 3D Universe we live in might be just such a brane — and that we detect the brane’s growth as cosmic expansion. “Astronomers measured that expansion and extrapolated back that the Universe must have begun with a Big Bang — but that is just a mirage,” says Afshordi.

The model also naturally explains our Universe’s uniformity...

Ultracold Big Bang experiment successfully simulates evolution of early universe

Ultracold Big Bang experiment successfully simulates evolution of early universe: Physicists have reproduced a pattern resembling the cosmic microwave background radiation in a laboratory simulation of the Big Bang, using ultracold cesium atoms in a vacuum chamber at the University of Chicago...


It turns out that under certain conditions, a cloud of atoms chilled to a billionth of a degree above absolute zero (-459.67 degrees Fahrenheit) in a vacuum chamber displays phenomena similar to those that unfolded following the Big Bang, Hung said.

"At this ultracold temperature, atoms get excited collectively. They act as if they are sound waves in air," he said. The dense package of matter and radiation that existed in the very early universe generated similar sound-wave excitations, as revealed by COBE, WMAP and the other experiments.

The synchronized generation of sound waves correlates with cosmologists' speculations about inflation in the early universe. "Inflation set out the initial conditions for the early universe to create similar sound waves in the cosmic fluid formed by matter and radiation," Hung said.

Ultracold Big Bang experiment successfully simulates evolution of early universe | UChicago News

Ultracold Big Bang experiment successfully simulates evolution of early universe | UChicago News: These excitations are called Sakharov acoustic oscillations, named for Russian physicist Andrei Sakharov, who described the phenomenon in the 1960s. To produce Sakharov oscillations, Chin’s team chilled a flat, smooth cloud of 10,000 or so cesium atoms to a billionth of a degree above absolute zero, creating an exotic state of matter known as a two-dimensional atomic superfluid.

Then they initiated a quenching process that controlled the strength of the interaction between the atoms of the cloud. They found that by suddenly making the interactions weaker or stronger, they could generate Sakharov oscillations.

The universe simulated in Chin’s laboratory measured no more than 70 microns in diameter, approximately the diameter as a human hair.

Swirls in the Afterglow of the Big Bang Could Set Stage for Major Discovery | Science/AAAS | News

Swirls in the Afterglow of the Big Bang Could Set Stage for Major Discovery | Science/AAAS | News . In a patch of sky, the random polarization pattern can be separated into two superimposed components: B-modes, in which the polarization forms right- or left-handed swirls, and E-modes, in which it does not. Whereas the coalescing of matter in the early universe can produce only E-modes, gravity waves rippling along during inflation should produce B-modes. The intensity of those "primordial" B-modes should reveal the energy density of the universe during inflation and help explain how it happened.

Cosmologist claims Universe may not be expanding : Nature News & Comment

Cosmologist claims Universe may not be expanding : Nature News: But, as Wetterich points out, the characteristic light emitted by atoms is also governed by the masses of the atoms' elementary particles, and in particular of their electrons. If an atom were to grow in mass, the photons it emits would become more energetic. Because higher energies correspond to higher frequencies, the emission and absorption frequencies would move towards the blue part of the spectrum. Conversely, if the particles were to become lighter, the frequencies would become redshifted.

Because the speed of light is finite, when we look at distant galaxies we are looking backwards in time — seeing them as they would have been when they emitted the light that we observe. If all masses were once lower, and had been constantly increasing, the colours of old galaxies would look redshifted in comparison to current frequencies, and the amount of redshift would be proportionate to their distances from Earth. Thus, the redshift would make galaxies seem to be receding even if they were not.

Planck shows almost perfect cosmos – plus axis of evil

Planck shows almost perfect cosmos – plus axis of evil: "The overall conclusion is that standard cosmology is an extremely good match to Planck data," said Efstathiou. "If I were an inflationary theorist I would be extremely happy."

...Planck reveals that one half of the universe has bigger variations than the other. Planck's detectors are over 10 times more sensitive and have about 2.5 times the angular resolution of WMAP's, giving cosmologists a much better look at this alignment. "We can be extremely confident that these anomalies are not caused by galactic emissions and not caused by instrumental effects..."

Daydreaming Beyond the Solar System with Warp Field Mechanics | Icarus Interstellar

Daydreaming Beyond the Solar System with Warp Field Mechanics | Icarus Interstellar: The loopholes, amazingly, can be found in mathematical equations. Those equations are tested using an instrument called the White-Juday Warp Field Interferometer. At JSC, Eagleworks has initiated an interferometer test bed that will try to generate and detect a microscopic instance of a little warp bubble...

By harnessing the physics of cosmic inflation, future spaceships crafted to satisfy the laws of these mathematical equations may actually be able to get somewhere unthinkably fast...

Dark matter, dark energy, dark… magnetism?

Dark matter, dark energy, dark… magnetism?:   In 2008 at the Complutense University of Madrid, Spain, they were playing with a particular version of a mutant gravity model called a vector-tensor theory, which they had found could mimic dark energy. Then came a sudden realisation. The new theory was supposed to be describing a strange version of gravity, but its equations bore an uncanny resemblance to some of the mathematics underlying another force. "They looked like electromagnetism," says Beltrán, now based at the University of Geneva in Switzerland. "We started to think there could be a connection."

So they decided to see what would happen if their mathematics described not masses and space-time, but magnets and voltages...

Crucially, inflation could also have boosted the new electromagnetic waves. Beltrán and Maroto found that this process would leave behind vast temporal modes: waves of electric potential with wavelengths many orders of magnitude larger than the observable universe. These waves contain some energy but because they are so vast we do not perceive them as waves at all.

Mathematics of Eternity Prove The Universe Must Have Had A Beginning - Technology Review

Mathematics of Eternity Prove The Universe Must Have Had A Beginning - Technology Review: Today, Audrey Mithani and Alexander Vilenkin at Tufts University in Massachusetts say that these models are mathematically incompatible with an eternal past. Indeed, their analysis suggests that these three models of the universe must have had a beginning too.

Their argument focuses on the mathematical properties of eternity--a universe with no beginning and no end. Such a universe must contain trajectories that stretch infinitely into the past.

However, Mithani and Vilenkin point to a proof dating from 2003 that these kind of past trajectories cannot be infinite if they are part of a universe that expands in a specific way.

Original spin: Was the universe born whirling? - space - 17 October 2011 - New Scientist

Original spin: Was the universe born whirling?: All other things being equal, you would have expected these galaxies generally to be spinning in random directions, according to local conditions when they formed. And that indeed was the case. In most sectors of the northern sky, equal numbers of galaxies were rotating to the right, or clockwise, and to the left, anticlockwise. But along one direction, at about 10 degrees to our own galaxy's spin axis, there were more left-handed spirals than right-handed ones...
"If this asymmetry is real, it means the universe has a net angular momentum..."
It is too early for him to have incorporated the details of the galaxy asymmetry into his work explicitly, but he sees a suggestive thread: an initially spinning universe brought on a parity-violating asymmetry in gravity that allowed matter to triumph over its antimatter rival. And that process left two marks behind: the axis of evil in the cosmic background radiation, and the inconspicuous alignment of galaxies that Longo has spotted.

Could the Big Bang have been a quick conversion of antimatter into matter?

Could the Big Bang have been a quick conversion of antimatter into matter?: ...Hajdukovic imagines the existence of a matter-antimatter repulsion that is significant only at short range; specifically, inside a black hole’s event horizon, or smaller than the Schwarzschild radius. Immediately after the gravitational Schwinger mechanism produces particle-antiparticle pairs, the repulsion force would cause a black hole to violently repel the opposite particle type. The result would be the conversion of nearly all matter into antimatter (or vice versa) in a very short time that depends on the size of the black hole.
Through calculations, Hajdukovic shows that the amount of matter that can be converted into antimatter (or vice versa) in one second could be up to 10128 kg, which is several orders of magnitude greater than the entire mass of the universe, about 1053 kg. If correct, it would mean that all of the matter in the universe could be converted into antimatter in a fraction of the Planck time...
... in his paper titled “Is dark matter an illusion created by the gravitational polarisation of the quantum vacuum,” he obtains a “striking equation” in agreement with observations and without invoking dark matter.

Gravity's bias for left may be writ in the sky - space - 05 March 2011 - New Scientist

Gravity's bias for left may be writ in the sky: The pair calculate that if gravity depended on just left or right-handed gravitons, that would have skewed the polarisation pattern in an obvious way. What's more, inflation would have stretched these effects to astronomical proportions, making them easily visible to astronomers...
Evidence of left-handed gravitons in the CMB would be "a triple discovery", says Lee Smolin of the Perimeter Institute in Waterloo, Ontario, Canada, who has worked with Magueijo and Benincasa on the subject. "It would confirm inflation, that gravity is quantum mechanical and that there is left-right asymmetry in quantum gravity."

Cosmos At Least 250x Bigger Than Visible Universe, Say Cosmologists� - Technology Review

Cosmos At Least 250x Bigger Than Visible Universe, Say Cosmologists� - Technology Review: "The breakthrough that Vardanyan and pals have made is to find a way to average the results of all the data in the simplest possible way. The technique they use is called Bayesian model averaging and it is much more sophisticated than the usual curve fitting that scientists often use to explain their data...

Instead of asking how well the model fits the data, its asks a different question: given the data, how likely is the model to be correct. This approach is automatically biased against complex models--it's a kind of statistical Occam's razor.