It cannot be a good place to start: there is no such thing as dark energy.
Dark matter & energy are just that. Totally hypothetical phenomenons to fill the gaps in a cosmological model & very little is known about it.http://www.space.com/8588-dark-energy-dark-matter-exist-scientists-allege.htmlDark Energy and Dark Matter Might Not Exist, Scientists Allege
"It's such an important thing — the microwave background," said astrophysicist Tom Shanks of Durham University in England. "All the results in dark energy and dark matter in cosmology hang on it, and that's why I'm interested in checking the results."
"When we checked radio sources in the WMAP background, we found more smoothing than the WMAP team expected," Shanks told SPACE.com. "That would have big implications for cosmology if we were proven right."
If this smoothing error is larger than thought, it could indicate that fluctuations measured in the intensity of the CMB radiation are actually smaller than they originally appeared. The size of these fluctuations is a key parameter used to support the existence of dark matter and dark energy.
With smaller ripples, there would be no need to invoke exotic concepts like dark matter and dark energy to explain the CMB observations, Shanks said. The researchers will report their findings in an upcoming issue of the journal Monthly Notices of the Royal Astronomical Society.
http://www.bbc.com/news/science-environment-20300100Supersymmetry theorises the existence of more massive versions of particles that have already been detected.
If found, they might help explain the phenomenon known as dark matter.
However, researchers at the LHCb detector have dealt a serious blow to hopes of finding them.
If supersymmetry is not an explanation for dark matter, then theorists will have to find alternative ideas to explain those inconsistencies in the Standard Model. So far researchers who are racing to find evidence of so called "new physics" have run into a series of dead ends.
New Doubt about Dark Matter
Tantalizing ‘signals’ from a handful of recent high-energy searches for dark matter are more likely the product of conventional astrophysics than the first tentative detections of the universe’s missing mass, say skeptical astrophysicists.
“A decade ago, no [one] would make these claims without first checking and re-checking that it couldn’t be from some normal astrophysical source,” Stacy McGaugh, an astrophysicist at Case Western Reserve University in Cleveland, told Forbes. “Nowadays, the attitude seems to be that if you don’t immediately recognize what it is, it must be dark matter; [with] no penalty for ‘crying wolf’ over and over again.”
Even so, the theoretical stakes remain high.
That’s because for the better part of a century, cosmological “cold dark matter” has been needed to explain the gravitational dynamics of much of the cosmos’ visible matter; including the rotation rates of massive galaxies like our own.
“By a very large margin, the matter we do see directly in galaxies does not produce enough gravity to hold the galaxies together; dark matter is invoked to provide the extra gravity needed,” Mordehai Milgrom, a physicist at Israel’s Weizmann Institute, told Forbes. That is, Milgrom says, if the standard laws of physics are used to calculate gravity as we know it.
And because non-baryonic (or exotic) dark matter is theorized to only interact with normal matter primarily via gravity, dark matter’s detection has inherently been problematic.
The need to invoke dark matter at all stems either from the product of unseen exotic particles that lie well beyond the ken of known physics or is the result of new physics in which gravity behaves differently on the largest scales. Neither scenario is easily tested.
For decades, however, experimental physicists have used both laboratory and astronomical observations from ground and space to search for this missing component.
One of the most recent, as noted this month in the journal Physical Review Letters, involves x-ray emissions from both the Perseus galaxy cluster and the nearby Andromeda galaxy.
Using the European Space Agency’s XMM-Newton telescope, researchers from Switzerland’s EPFL Laboratory of Particle Physics and Cosmology and Leiden University in The Netherlands report that this observed excess of x-ray photons may represent signals of decay by sterile neutrinos. That is, heretofore unverified, hypothetical dark matter particles.
“We have been searching for such a signal since 2005,” Alexey Boyarsky, a professor of physics at Leiden University and the paper’s lead author, told Forbes. “The signal is at the lowest range of experimental sensitivity, and if it were easy to find, we would have found it long ago.”
Boyarsky points out that among the models that are consistent with the dark matter interpretation of this signal, the sterile neutrino is probably the simplest and one of the most natural. Such a particle, he says, can interact with normal matter only via quantum mechanical “mixing” with ordinary neutrinos.
Therefore, says Boyarsky, it is very hard to “catch.”
MIT physicist Paolo Zuccon counters that the sterile neutrino’s existence has also not been proven. “They guess its mass; they guess its properties; and, in particular, how it decays,” said Zuccon told Forbes. “All in all, this claim seems a little weak.”
Or as McGaugh puts it: “Based on those data, I would not claim to have detected anything. This looks like a classic case of the over-interpretation of noisy astronomical data.”
However, Zuccon himself has been involved in searches for this stealthy matter, using a spectrometer mounted on the exterior of the International Space Station (ISS).
Zuccon and colleagues analyzed two and a half years of data from the Alpha Magnetic Spectrometer (AMS), the ISS particle detector that recorded a flux of millions of cosmic rays from all over the galaxy. They found an excess of positrons (antiparticles of electrons) at energies of around 8 gigaelectron-volts (GeV) which the researchers say fits some dark matter models.
“But we are not yet in the position to discriminate between the dark matter hypothesis and an astrophysical source [such as] pulsars,” said Zuccon, who is involved with the AMS search. “Only more data from AMS and/or from other measurements will allow an answer.”
Yet as reported by Nature News earlier this month, ESA’s Planck telescope failed to find the imprint of similar positron excesses in the Cosmic Microwave Background, which logically should have been seen if dark matter particles were also colliding and annihilating at comparable rates in the primordial universe.
McGaugh says in the case of the MIT positron signals, the possible signature of dark matter would correspond to an upper energetic limit on the dark matter particle’s actual decay.
“If they see a [energetic] sharp edge like that which corresponds to a plausible dark matter particle, then I’ll get very interested,” said McGaugh. “Until then, they’ve got nothing that can’t be better understood as astrophysical.”
Hooper emphasizes that, in fact, he thinks the Fermi signal is still “well fit” by models of dark matter being annihilated in the galactic center.*
McGaugh disagrees.
“Until both known and un-anticipated astrophysical sources are excluded as reasons for the observed signal, claims about it being due to dark matter are exaggerated at best,” said McGaugh.
Dark matter theory persists in part because in cosmic large scale structure, its unseen presence seems to shape the makeup of clusters and superclusters of galaxies along filaments of the cosmic web. Thus, again, without invoking dark matter or alternative theories of gravity, such structure is hard to explain.
“This sanguine attitude has been around a long time,” said McGaugh. “Every five years for the past twenty years, I have heard the confident declaration ‘in five years, we’ll know what dark matter is.’ Obviously, that’s never happened.”
Serious blow to dark matter theory
http://www.eso.org/public/news/eso1217/#3Dark energy/dark matter pipe dream
http://davidpratt.info/cosmo.htm#c4