Warmhole or a Supermassive Blackhole

           Artist's impression of a supermassive black hole consuming matter from its accretion disk.

Although we have a pretty good idea that our galaxy contains a supermassive black hole at its core, there could be another — albeit rather exotic — explanation for our observations of Sagittarius A*. It might be a wormhole.

This is according to two researchers who explore the possibility in a new paper submitted to the arXiv pre-print service. Although their work is purely theoretical, Zilong Li and Cosimo Bambi of Fudan University in Shanghai have identified a specific emission signature surrounding their hypothetical wormhole, a signature that may be detected by a sophisticated instrument that will soon be attached to one of the world’s most powerful telescopes.

ANALYSIS: Wormhole Time Travel ‘Possible’ (If You’re a Photon)

Sagittarius A* (or Sgr A*) is a region in the Milky Way’s core that generates powerful radio waves and astronomers have long suspected that it is the location of a black hole approximately 4 million times the mass of our sun. It wasn’t until astronomers were able to track stars orbiting close to the suspected black hole’s event horizon, however, that the supermassive black hole was confirmed to be there.

But supermassive black holes are a conundrum.

Now we know what signature our supermassive black hole generates, astronomers have discovered that the majority of other galaxies also possess supermassive black holes in their cores. Even when looking into the furthest cosmological distances at the youngest known galaxies, they also appear to host these black hole behemoths.

For a black hole to gain so much mass, it’s logical to think they need lots of time to pile on the mass — eating interstellar gas, stars and other galactic material. But to explain the earliest supermassive black holes in the youngest galaxies, there had to be some as-yet to be understood rapid growth mechanism.

ANALYSIS: Spooky Connection: Wormholes and the Quantum World

According to Li and Bambi, however, to explain our observations of Sgr A* and other galaxies’ cores, a primordial consequence of Einstein’s general theory of relativity may be called into play instead, thereby sidestepping the puzzle of how supermassive black holes grew so big so quickly.

“While of exotic nature, at least some kinds of primordial WHs (wormholes) can be viable candidates to explain the supermassive objects at the center of galaxies,” they write. “These objects have no solid surface, and therefore they may mimic the presence of an event horizon. They would have been produced in the early Universe and grown during inflation, so they could explain their presence even at very high redshift.”

High redshift galaxies are the youngest galaxies we can observe; where the galactic light has traveled billions of light-years, with frequencies shifted to the reddest part of the electromagnetic spectrum.

The type of wormhole that can mimic a black hole could only have been formed during the Big Bang, exerting a mass millions of times our sun’s mass, possibly explaining why the earliest galaxies appear to have supermassive black holes in their cores; they may not be black holes at all, they could in fact be gargantuan wormholes, linking disparate regions of space and time. (Though whether they can be traversed would likely remain a mystery.)

ANALYSIS: Stephen Hawking’s Time Machine

This may sound like some theoretical fun and games bordering on science fiction, but Li and Bambi have identified a powerful new instrument that could be used to differentiate emissions from space plasma surrounding the Sgr A* black hole or hypothetical wormhole.

GRAVITY will soon be installed at the ESO’s Very Large Telescope (VLT) in the Atacama Desert in Chile and will be used to observe the galactic center with unprecedented precision. The researchers hope to analyze emission data from energized gases (or plasma) that could be found around the object inside Sgr A*. Should the object in fact be a wormhole, that plasma will generate a very different signature as the hypothetical wormhole will be physically smaller than a supermassive black hole.

By modeling a hot blob of plasma trapped in the warped spacetime surrounding a black hole and a wormhole, Li and Bambi noticed two very different emission signatures that both cases will generate. A wormhole would generate a “very narrow emission line,” whereas a black hole would have spectra that is “broad and skewed as a result of special and general relativistic effects,” they write.

It is rare that such exotic theories could be supported or disproved by an instrument that will be commissioned within a couple of years, but it will be very exciting to see whether the plasma emissions around the object in Sgr A* are more black hole-like or wormhole-like. And although the chances are slim, if the latter is detected, it could re-write our understanding of the Cosmos.

Source: arXiv via arXiv blog

Are we gona find Dark Sector

Dwarf planet could illuminate the dark sector

Could a dwarf planet in the Kuiper belt reveal antigravity?

A dwarf-planet candidate called UX25 and its tiny satellite could provide the first evidence of a new cosmological model that includes antigravity, say Alberto Vecchiato and Mario Gai of the Astrophysical Observatory of Turin in Italy. The model dispenses with concepts such as dark matter, dark energy and cosmic inflation, and the astronomers say that it could be tested by observing the motion of the two objects as they move through the outer solar system.

In 1915 Albert Einstein's fledgling general theory of relativity received a major credibility boost when it was used to explain a discrepancy in Mercury's orbit that could not be accounted for by Newtonian physics alone. Now, nearly a century later, Vecchiato and Gai have calculated that UX25 and its tiny satellite – which orbit the Sun in the Kuiper belt beyond Neptune – could be used as a "natural laboratory" to test an ambitious new model of the universe.

Gravitational charges

Developed by CERN physicist Dragan Hajdukovic, the model is based upon the concept that empty space – also known as the quantum vacuum – is not really empty at all. Instead, it consists of "virtual" matter and antimatter particles that constantly blink in and out of existence. Hajdukovic's idea is that these particles have opposing gravitational charges, similar to positive and negative electrical charges. He further predicts that in the presence of a gravitational field, virtual particles in the quantum vacuum will generate a secondary gravitational field that has an amplifying effect. The end result is that galaxies and other objects will appear to have stronger gravitational fields than would be predicted by the mass of their stars alone – a discrepancy that most astronomers explain by invoking the hypothetical and mysterious substance known as dark matter.

In Hajdukovic's new model of the universe, there is also no need for dark energy, the enigmatic force that scientists think is causing the universe to expand at an accelerated rate. The idea is that if virtual particles have gravitational charges, then space–time itself is imbued with a small charge that causes objects to repel each other. His theory would also negate the need for cosmic inflation, a theorized rapid swelling of the early universe when space–time itself expanded faster than the speed of light. "My theory provides encouraging initial answers to many different fundamental questions in physics," says Hajdukovic.

Distant elliptical orbits

Hajdukovic has previously suggested that his theory could be tested if a minor planet with a small satellite that has an elliptical orbit can be found. The system would need to be located far from the Sun and other massive bodies.

Now, Vecchiato and Gai suggest that Hajdukovic's model can be tested by using existing ground and space telescopes to observe the UX25 system – which is about 43 times farther from the Sun than is the Earth. "The properties of quantum vacuums described in Hajdukovic's theory would apply an additional [gravitational] force on UX25, perturbing the orbit of the system," Vecchiato explained tophysicsworld.com.

Wobbling moon

Hajdukovic's model predicts that the wobble, or "precession rate", of UX25's tiny moon around the dwarf planet should be larger than is predicted by classical physics. Where Newtonian physics predicts a precession rate of 0.0064 arc seconds – too small to be observed with current methods – Hajdukovic's theory predicts that the rate should be 0.23 arc seconds per period – just enough to be detectable by NASA's Hubble Space Telescope and the soon-to-be-launched James Webb Space Telescope.

According to Vecchiato and Gai, a large ground-based telescope such as the Very Large Telescope might also be able to make the necessary observations of UX25.

Evidence for Hajdukovic's theory would result in a dramatic change in perspective for physicists, says Gai. "Most scientists today think quantum physics is mainly restrained to the microscopic world...In this case, the natural microscopic behaviour of empty space would result in a cumulative, long-range effect acting up to cosmic scales."

The proposal appears on the arXiv preprint server.

About the author

Ker Than is a science writer based in the US

Brtish cosmologists are puzzled: they predict that the Universe should not have lasted for more than a second. This startling conclusion is the result of combining the latest observations of the sky with the recent discovery of the Higgs boson. Robert Hogan of King's College London (KCL) will present the new research on 24 June at the Royal Astronomical Society's National Astronomy Meeting in Portsmouth.

After the Universe began in the Big Bang, it is thought to have gone through a short period of rapid expansion known as 'cosmic inflation'. Although the details of this process are not yet fully understood, cosmologists have been able to make predictions of how this would affect the Universe we see today.

In March 2014, researchers from the BICEP2 collaboration claimed to have detected one of these predicted effects. If true, their results are a major advance in our understanding of cosmology and a confirmation of the inflation theory, but they have proven controversial and are not yet fully accepted by cosmologists.

In the new research, scientists from KCL have investigated what the BICEP2 observations mean for the stability of the Universe. To do this, they combined the results with recent advances in particle physics. The detection of the Higgs boson by the Large Hadron Collider was announced in July 2012; since then, much has been learnt about its properties.

Measurements of the Higgs boson have allowed particle physicists to show that our universe sits in a valley of the 'Higgs field', which describes the way that other particles have mass. However, there is a different valley which is much deeper, but our universe is preventing from falling into it by a large energy barrier.

The problem is that the BICEP2 results predict that the universe would have received large 'kicks' during the cosmic inflation phase, pushing it into the other valley of the Higgs field within a fraction of a second. If that had happened, the universe would have quickly collapsed in a Big Crunch.

"This is an unacceptable prediction of the theory because if this had happened we wouldn't be around to discuss it" said Hogan, who is a PhD student at KCL and led the study.

Perhaps the BICEP2 results contain an error. If not, there must be some other -- as yet unknown -- process which prevented the universe from collapsing.

"If BICEP2 is shown to be correct, it tells us that there has to be interesting new particle physics beyond the standard model" Hogan said.

higgs mechanish

Brief History of the Higgs Mechanism

A Brief History of the Higgs Mechanism: The scientific work behind the Higgs boson

The electroweak theory, which unifies the electromagnetic and weak interactions of elementary particles, has, since 1970, received experimental support to a precision unprecedented in the history of science. This unification involves a close relationship between the massless photon, which carries the long-range electromagnetic force, and the W and Z vector bosons, which carry the short-range weak force and must therefore be very massive. Prior to the invention of the Higgs mechanism, it was not known how to formulate a consistent relativistic field theory with a local symmetry which could contain both massless and massive force carriers.

In 1962, Goldstone’s theorem had shown that spontaneous breaking of symmetry in a relativistic field theory results in massless spin-zero bosons, which are excluded experimentally. In a paper published in Physics Letters on 15 September 1964 (received on 27 July 1964), Peter Higgs showed that Goldstone bosons need not occur when a local symmetry is spontaneously broken in a relativistic theory (1). Instead, the Goldstone mode provides the third polarisation of a massive vector field. The other mode of the original scalar doublet remains as a massive spin-zero particle – the Higgs boson.

Higgs wrote a second short paper describing what came to be called “the Higgs model” and submitted it to Physics Letters, but it was rejected on the grounds that it did not warrant rapid publication. Higgs revised the paper and submitted it to Physical Review Letters, where it was accepted (2), but the referee, who turned out to be Yoichiro Nambu, asked Higgs to comment on the relation of his work to that of Francois Englert and Robert Brout, which was published in Physical Review Letters on 31 August 1964, the same day his paper was received. Higgs had been unaware of their work, because the Brussels group did not send preprints to Edinburgh. Higgs’ revised paper drew attention to the possibility of a massive spin-zero boson in its final paragraph. During October 1964, Higgs had discussions with Gerald Guralnik, Carl Hagen and Tom Kibble, who had discovered how the mass of non-interacting vector bosons can be generated by the Anderson mechanism (4).

The previous year, Philip Anderson had pointed out that, in a superconductor where the local gauge symmetry is broken spontaneously, the Goldstone (plasmon) mode becomes massive due to the gauge field interaction, whereas the electromagnetic modes are massive (Meissner effect) despite the gauge invariance (5). However, he did not discuss any relativistic model and so, since Lorentz invariance was a crucial ingredient of the Goldstone theorem, he did not demonstrate that it could be evaded. In Higgs’ second 1964 paper (2) he referred to Anderson’s work in a way which implied that Anderson knew about the non-relativistic counterpart of the Higgs boson. In fact, Anderson didn’t and it was not until 1981 that an unexpected feature of the Raman spectrum of NbSe2 was understood to be due to “a massive collective mode which exists in all superconductors – the oscillation of the amplitude of the superconducting gap” (6), the only Higgs boson  to be discovered experimentally before 2012.

The search for the Higgs boson became a major objective of experimental particle physics. Although the best fit to all the electroweak precision measurements gave its mass between 52 and 110 GeV, it was excluded below 114 GeV. Its mass could not exceed 1 TeV if the electroweak theory itself is to remain valid up to this energy scale, precisely the range that is within reach CERN’s Large Hadron Collider. We know now that the ATLAS and CMS have found a Higgs-like boson at a mass of around 126 GeV which increasingly looks like having all the properties of the Standard Model Higgs boson.

Peter Higgs’ work was a crucial step on the road to a unified theory of the forces of Nature and is clearly basis for an experimental programme to look at further details of the discovered particle and its extensions beyond the Standard Model.

(1) P.W. Higgs, Phys. Lett. 12 (1964) 132

(2) P.W. Higgs, Phys. Rev. Lett. 13 (1964) 508

(3) F. Englert and R. Brout, Phys. Rev. Lett. 13 (1964) 321

(4) G.S. Guralnik, C.R. Hagen and T.W.B. Kibble, Phys. Rev. Lett. 13 (1964) 585

(5) P.W. Anderson, Phys. Rev. 130 (1963) 439

(6) P.B. Littlewood and C.M. Varma, Phys. Rev. Lett. 47 (1981) 811

Time Travel

Using photons, scientists have simulated a way that quantum particles could travel through a wormhole back in time.

Image: edobric/Shutterstock

Physicists at the University of Queensland in Australia have used photons - single particles of light - to simulate quantum particles travelling through time and study their behaviour.

They were hoping to find out more about whether time travel would be possible at the quantum level - a theory first predicted in 1991.

In the study, the researchers simulated the behaviour of a single photon that travels through a wormhole and interacts with its older self. This is known as a closed timelike curve - a closed path in space-time that returns to the same starting point in space but at an earlier time. Their study is published in Nature Communications.

They did this by making use of a mathematical equivalence between two cases, lead author Martin Ringbauer told The Speaker. 

In the first case, photon one "travels trough a wormhole into the past, then interacts with its older version,” Ringbauer explained. And in the second case, photon two travels through normal space-time, but interacts with another photon that is trapped inside a closed timelike curve forever.

"We used single photons to do this but the time-travel was simulated by using a second photon to play the part of the past incarnation of the time travelling photon," said University of Queensland physics professor Tim Ralph. 

The research will hopefully help researchers bridge the gap between two critical theories, said Ringbuaer.

"The question of time travel features at the interface between two of our most successful yet incompatible physical theories – Einstein's general relativity and quantum mechanics," Ringbuaer explained.

"Einstein's theory describes the world at the very large scale of stars and galaxies, while quantum mechanics is an excellent description of the world at the very small scale of atoms and molecules,” he added.

According to Einstein’s theory, it could be possible to travel back in time by following a closed timelike curve. However physicists and philosophers have struggled with this theory given the paradoxes such as the grandparents paradox, where a time traveller could prevent their grandparents from meeting, thus preventing the time traveller’s birth in the first place.

But in 1991 it was suggested that time travel in the quantum world would avoid these kinds of paradoxes because the properties of quantum particles are “fuzzy” and “uncertain” - and this is the one of the first times anyone has simulated the behaviour of such a scenario.

“We see in our simulation (as was predicted in 1991) how many effects become possible, which are forbidden in standard quantum mechanics,” said Ringbauer. “For example it is possible to perfectly distinguish different states of a quantum system, which are usually only partially distinguishable. This makes quantum cryptography breakable and violates Heisenberg’s uncertainty principle. We also show that photons behave differently, depending on how they were created in the first place.”

Are we getting closer

A team of quantum-computing experts in the US and Switzerland has published a paper in Science that casts doubt over the ability of the D-Wave Two quantum processor to perform certain computational tasks. The paper, which first appeared as a preprint earlier this year, concludes that the processor – built by the controversial Canadian firm D-Wave Systems – offers no advantage over a conventional computer when it is used to solve a benchmark computing problem.

While the researchers say that their results do not rule out the possibility that the processor can outperform conventional computers when solving other classes of problems, their work does suggest that evaluating the performance of a quantum computer could be a much trickier task than previously thought. D-Wave has responded by saying that the wrong benchmark problem was used to evaluate its processor, while the US–Swiss team now intends to do more experiments using different benchmarks

read more on         http://physicsworld.com/cws/article/news/2014/jun/20/is-d-wave-quantum-computer-actually-a-quantum-computer