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"Everything should be as simple as it is, but not simpler", Albert Einstein
Browsing All Posts filed under »DARK MATTER«
Secrets Of The Dark Universe: Simulating The Sky
An astonishing 99.6% of our Universe is dark. Observations indicate that the Universe consists of 70% of a mysterious dark energy and 25% of a yet-unidentified dark matter component, and only 0.4% of the remaining ordinary matter is visible. Understanding the physics of this dark sector is the foremost challenge in cosmology today. Sophisticated simulations […]
Twist in dark matter tale hints at shadow Milky Way
April 11, 2013
THE HUNT for some of the most wanted stuff in the universe took a new twist this week with the first results from a high-profile, space-based dark matter detector. The results are inconclusive, but, if combined with recent theory, they hint at something exciting. Could the universe have a dark side, complete with its own […]
Double-Disk Dark Matter
March 12, 2013
JiJi Fan, Andrey Katz, Lisa Randall, Matthew Reece Based on observational tests and constraints on halo structure, dark matter is generally taken to be cold and essentially collisionless. On the other hand, given the large number of particles and forces in the visible world, a more complex dark sector could be a reasonable or even […]
Ground-Based Instruments Could Detect Cosmic Wall Structures
January 14, 2013
Invisible sheetlike structures, which might pervade space and contribute to dark matter or dark energy, could be revealed as they pass by Earth-based detectors. One of the potential explanations for the Universe’s mysterious dark matter and dark energy is a cosmic latticework of energetic “domain walls.” In Physical Review Letters, a team proposes the first […]
Direct Detection of Dark Matter through Quantum Decoherence
December 22, 2012
C. Jess Riedel Astrophysical and cosmological observations suggest that the majority of mass in the universe is made up of invisible dark matter. Although various pieces of indirect evidence about its nature have been collected, the direct detection of dark matter has eluded experimental searches despite extensive effort. If the mass of dark matter is […]
The underground lab searching for wimps
November 18, 2012
At Gran Sasso National Laboratory, nearly a mile beneath an Italian mountain range, physicists are trying to isolate the particles they believe hold the universe together Drive west along Italy’s Autostrada 24 and you will come to the Gran Sasso mountain range 80 miles before Rome. This is one of Italy’s most spectacular national parks […]
ATLAS Experiment: Search for dark matter candidates
October 23, 2012
Search for dark matter candidates and large extra dimensions in events with a jet and missing transverse momentum with the ATLAS detector A search for new phenomena in events with a high-energy jet and large missing transverse momentum is performed using data from proton-proton collisions at sqrt(s)=7 TeV with the ATLAS experiment at the Large […]
Dark Energy and Dark Matter as Inertial Effects
October 16, 2012
Serkan Zorba A rigidly rotating model of the universe is postulated. It is shown that dark energy and dark matter are cosmic inertial effects resulting from such a cosmic rotation, corresponding to centrifugal and a combination of centrifugal and the Coriolis forces, respectively. The physics and the cosmological and galactic parameters obtained from the model […]
Dark matter effect might be explained …
September 18, 2012
… by modified way to calculate inertial mass One of the first observations suggesting the existence of an invisible dark matter came in 1933 when astronomer Fritz Zwicky noticed that galaxy clusters were more energetic than they should be, according to the mass of visible stars in them, and he proposed dark matter to explain […]
Heavy photons are too light to be behind dark matter
September 15, 2012
SADLY, dark matter is not made of light. That may sound obvious, but many physicists were hoping that photons – particles of light – could help us to piece together the nature of the mysterious stuff thought to make up 85 per cent of the universe’s matter. Instead, readings from Vitor Cardoso of the Technical […]
Dark-matter hope fades in microwave haze
September 10, 2012
The latest results from the Planck space telescope have confirmed the presence of a microwave haze at the centre of the Milky Way. However, the haze appears to be more elongated than originally thought, which casts doubt over previous claims that annihilating dark matter is the cause of the emissions. A roughly spherical haze of […]
Gravitational Field Equations and Theory of Dark Energy and Dark Matter
September 7, 2012
Mathematicians offer unified theory of dark matter, dark energy, altering Einstein field equations A pair of mathematicians—one from Indiana University and the other from Sichuan University in China—have proposed a unified theory of dark matter and dark energy that alters Einstein’s equations describing the fundamentals of gravity. Shouhong Wang, a professor in the IU College […]
Plenty of dark matter near the Sun
August 9, 2012
Astronomers at the University of Zürich and the ETH Zürich, together with other international researchers, have found large amounts of invisible “dark matter” near the Sun. Their results are consistent with the theory that the Milky Way Galaxy is surrounded by a massive “halo” of dark matter, but this is the first study of its […]
XENON100 sets record limits for dark matter
July 18, 2012
Scientists from the XENON collaboration announced a new result from their search for dark matter. The analysis of data taken with the XENON100 detector during 13 months of operation at the Gran Sasso Laboratory (Italy) provided no evidence for the existence of Weakly Interacting Massive Particles (WIMPs), the leading dark matter candidates. Two events being […]
Dark matter filament found, scientists say
July 5, 2012
By Amina Khan, Los Angeles Times The mysterious stuff called dark matter is thought to act as the spider silk for the cosmic web of the universe. But although it makes up most of the matter in the universe, scientists have been able to find only clumps of it in the web’s galaxy-filled “nodes,” not […]
Machian gravity and the giant galactic forces
June 30, 2012
Santanu Das One of the main motivations behind formulating the general theory of relativity was to provide a mathematical description to the Machian gravity’s principle. However, soon after its formulation, it was realized that the theory does not follow Mach’s principle. As the theoretical predictions were matching with the observations, Einstein believed that the theory […]
Dark matter tracks could give earliest view of Universe
June 21, 2012
By Jason Palmer Researchers have come up with a way to glimpse the infant Universe by decoding the earliest ripples in its light. They say this can be achieved by capturing the specific radio wavelength of 21cm from the heavens. The trick is to tell the difference between 21cm waves from our galaxy and those […]
Euclid telescope to probe dark universe
June 20, 2012
Europe has given the final go-ahead to a space mission to investigate the “dark universe”. The Euclid telescope will look deep into the cosmos for clues to the nature of dark matter and dark energy. These phenomena dominate the Universe, and yet scientists concede they know virtually nothing about them. European Space Agency (Esa) member states made […]
Is Dark Matter a Glimpse of a Deeper Level of Reality?
June 11, 2012
(……) String theorists and other would-be unifiers of physics face a basic problem. The theories they seek to unify, quantum field theory and Einstein’s general theory of relativity, are well-grounded and well-tested, yet mutually incompatible. Reconciling them will demand that some deeply held intuition must give way. One such intuition is that the world exists […]
Crisis averted: Dark matter was there all along
May 24, 2012
by Lisa Grossman Fans of dark matter can rest easy. A study published last month raised eyebrows by suggesting that our cosmic neighbourhood is empty of the extra mass needed to hold the galaxy together. But a re-analysis shows that the dark matter was there all along. Dark matter is the mysterious, invisible stuff that makes up 83 […]
Matière noire: polémique entre astrophysiciens
May 24, 2012
Nous ne voyons pas de matière noire dans notre coin de Galaxie, clamait une équipe d’astrophysiciens. Vos travaux sont «incorrects» les tance une autre équipe, dans un article soumis à la critique des pairs sur le site arXiv.org qui vient leur répliquer de manière assez sévère. Dessin: la vision classique de la matière noire dans notre galaxie. L’affaire démarre […]
Aberration features in directional dark matter detection
May 11, 2012
Nassim Bozorgnia, Graciela B. Gelmini, Paolo Gondolo The motion of the Earth around the Sun causes an annual change in the magnitude and direction of the arrival velocity of dark matter particles on Earth, in a way analogous to aberration of stellar light. In directional detectors, aberration of weakly interacting massive particles (WIMPs) modulates the […]
Serious Blow to Dark Matter Theories?
April 18, 2012
New study finds mysterious lack of dark matter in Sun’s neighbourhood The most accurate study so far of the motions of stars in the Milky Way has found no evidence for dark matter in a large volume around the Sun. According to widely accepted theories, the solar neighbourhood was expected to be filled with dark […]
Dark Matter Annihilation at the Fermi Large Area Telescope?
April 17, 2012
A Tentative Gamma-Ray Line from Dark Matter Annihilation at the Fermi Large Area Telescope Christoph Weniger The observation of a gamma-ray line in the cosmic-ray fluxes would be a smoking-gun signature for dark matter annihilation or decay in the Universe. We present an improved search for such signatures in the data of the Fermi Large […]
Dark Matter collisions with the Human Body
April 9, 2012
Katherine Freese, Christopher Savage We investigate the interactions of Weakly Interacting Massive Particles (WIMPs) with nuclei in the human body. We are motivated by the fact that WIMPs are excellent candidates for the dark matter in the Universe. Our estimates use a 70 kg human and a variety of WIMP masses and cross-sections. The contributions […]
Fermi Provides New Insights on Dark Matter
April 2, 2012
http://youtu.be/i5ucytz2C7I There’s more to the cosmos than meets the eye. About 80 percent of the matter in the universe is invisible to telescopes, yet its gravitational influence is manifest in the orbital speeds of stars around galaxies and in the motions of clusters of galaxies. Yet, despite decades of effort, no one knows what this […]
Dark Matter Core Defies Explanation
March 2, 2012
This composite image shows the distribution of dark matter, galaxies, and hot gas in the core of the merging galaxy cluster Abell 520, formed from a violent collision of massive galaxy clusters. The natural-color image of the galaxies was taken with NASA’s Hubble Space Telescope and with the Canada-France-Hawaii Telescope in Hawaii. Superimposed on the […]
Axion Dark Matter and Cosmological Parameters
February 23, 2012
Blame dark matter underdog for mystery missing lithium by David Shiga AN UNDERDOG dark-matter particle could explain why the universe seems strangely low on lithium. If the idea holds up, it will be a boon in the hunt for dark matter, the stuff needed to account for 80 per cent of the universe’s matter. In the […]
Stars containing dark matter should look different from other stars
February 20, 2012
Finding evidence for dark matter – the unknown substance that theoretically makes up 23% of the universe – has been one of the biggest challenges in modern cosmology. Several experiments are underway to detect dark matter candidates known as Weakly Interacting Massive Particles (WIMPs) as they travel through the Earth. And experiments at the Large […]
How to spot a dark-matter galaxy
January 18, 2012
by Lisa Grossman If we could don dark matter glasses and look at the universe around us, we might see thousands of miniature galaxies swarming about the luminous spirals that make up the Milky Way and Andromeda. We can’t – but we have the next best thing. A technique known as gravitational lensing has allowed […]
What Higgs result means for dark matter conspiracy
December 21, 2011
RECENT hints of a featherweight Higgs boson don’t just take us nearer to a complete standard model of physics. The results affect a possible link between the Higgs and dark matter, the invisible stuff making up 80 per cent of the universe’s matter. The Higgs is the last remaining hole in the standard model, the […]
Searching for Dark Matter in Exoplanet Data
December 10, 2011
Our galaxy could be filled with asteroid-size black holes that presumably formed shortly after the big bang. If they exist in large numbers, these so-called primordial black holes would serve as the dark matter that keeps stars gravitationally glued inside galaxies. None of these primordial black holes have been detected so far, but a new […]
The Axion Dark Matter eXperiment
December 7, 2011
Dmitry Lyapustin The Axion is a particle arising from the Peccei-Quinn solution to the strong CP problem. Peccei-Quinn symmetry breaking in the early universe could produce a large number of axions which would still be present today, making the axion a compelling dark matter candidate. The goal of the Axion Dark Matter eXperiment (ADMX) is […]
Dark matter particles may be heavyweights after all
November 30, 2011
by Lisa Grossman - newscientist.com Dark matter is slowly running out of places to hide. Two new looks at the gamma-ray sky suggest that if the mysterious matter is a particle, it is heavier than 40 gigaelectronvolts, about 44 times the mass of a proton. That contradicts hints from three experiments on Earth that pointed to a lightweight dark matter […]
Quantum vacuum and dark matter
November 28, 2011
Dragan Slavkov Hajdukovic Abstract Recently, the gravitational polarization of the quantum vacuum was proposed as alternative to the dark matter paradigm. In the present paper we consider four benchmark measurements: the universality of the central surface density of galaxy dark matter haloes, the cored dark matter haloes in dwarf spheroidal galaxies, the nonexistence of dark […]
Lectures on Cosmology and Particle Physics
October 20, 2011
by Sean Carroll Lecture One: Introduction to Cosmology http://youtu.be/vUNtO2r_-eo Lecture Two: Dark Matter http://youtu.be/Gq-lGX2PRrc Lecture Three: Dark Energy http://youtu.be/cYVj2RhXxeU Lecture Four: Thermodynamics and the Early Universe http://youtu.be/178mMnGvWs0 Lecture Five: Inflation and Beyond http://youtu.be/M1PeXaMqKto
Dark matter mystery deepens
October 17, 2011
Like all galaxies, our Milky Way is home to a strange substance called dark matter. Dark matter is invisible, betraying its presence only through its gravitational pull. Without dark matter holding them together, our galaxy’s speedy stars would fly off in all directions. The nature of dark matter is a mystery — a mystery that […]
How a Team of Enthusiasts Are Mapping Dark Matter
October 11, 2011
Earthly skills like handwritten signature verification turn out to be useful on a cosmological scale as well When the Euclid mission lifts off at the end of this decade, it will map galaxy clusters in infrared and visible light, helping to blueprint the large-scale structure of the universe. And a bunch of amateur science geeks […]
Dark Matter and its Effects on Helioseismology
October 7, 2011
Ryan Hamerly, Alexander Kosovichev Helioseismology can be used to place new constraints on the properties of dark matter, allowing solar observations to complement more conventional dark matter searches currently in operation. During the course of its lifetime, the Sun accretes a sizeable amount of dark matter. This accreted matter affects the heat transport of the […]
Most ancient supernovas discovered
October 5, 2011
Supernovas — stars in the process of exploding — open a window onto the history of the elements of Earth’s periodic table as well as the history of the universe. All of those heavier than oxygen were formed in nuclear reactions that occurred during these explosions. The most ancient explosions, far enough away that their […]
Supernovae, Dark Energy, and the Accelerating Universe
October 4, 2011
Using very distant supernovae as standard candles, one can trace the history of cosmic expansion and try to find out what’s currently speeding it up. Saul Perlmutter For millennia, cosmology has been a theorist’s domain, where elegant theory was only occasionally endangered by inconvenient facts. Early in the 20th century, Albert Einstein gave us new […]
Could primordial black holes be dark matter?
September 21, 2011
“We know that about 25% of the matter in the universe is dark matter, but we don’t know what it is,” Michael Kesden tellsPhysOrg.com. “There are a number of different theories about what dark matter could be, but we think one alternative might be very small primordial black holes.” When many of us think about black […]
Dwarf galaxies suggest dark matter theory may be wrong
September 17, 2011
Scientists’ predictions about the mysterious dark matter purported to make up most of the mass of the Universe may have to be revised. Research on dwarf galaxies suggests they cannot form in the way they do if dark matter exists in the form that the most common model requires it to. That may mean that […]
Recent results on the low mass dark matter WIMP controversy
September 10, 2011
David B. Cline We review the confused situation concerning evidence for low-mass WIMPs. In the past one half year there have been new results concerning the existence of WIMPs at low mass including the new XENON 100, 100-day data, additional CDMS results, the publication of annual variation data from LVD and Borexino and new CoGeNT […]
Third experiment sees hints of dark matter
September 7, 2011
A third experiment has detected tantalising signs of dark matter. The finding raises more questions than answers, however, as two other experiments have found no sign of the mysterious stuff, which is thought to create the gravity that holds spinning galaxies together, accounting for about 85 per cent of all matter in the universe. The new […]
ERIS: World’s first realistic simulation of the formation of the Milky Way
August 30, 2011
— After nine months of number-crunching on a powerful supercomputer, a beautiful spiral galaxy matching our own Milky Way emerged from a computer simulation of the physics involved in galaxy formation and evolution. The simulation by researchers at the University of California, Santa Cruz, and the Institute for Theoretical Physics in Zurich solves a longstanding […]
Dark Energy, Dark Matter, Dark Force: Not Afraid Of The Dark
August 19, 2011
Sascha Vongehr The public repulsion against dark matter and dark energy is really annoying. Rob Knop at scientopia compares it to 17th century catholic church mentality; Ethan picks it up and bangs the dark matter explains everything drum although dark matter does not fit very well to galaxy rotation curves – Modified Newtonian Dynamics (MOND) fits much better: (From: Begeman, Broeils, […]
Dark matter may solve ‘radio filaments’ mystery
June 29, 2011
Unexplained “filaments” of radio-wave emission close to our galaxy’s centre may hold proof of the existence of dark matter, researchers have said. Dark matter is believed to make up most of the mass of our Universe, but it has yet to be definitively spotted. A report now suggests the filaments’ emission arises from dark matter […]
Fermi Space Telescope Fails to See Evidence Of Dark Matter
June 21, 2011
If dark matter fills the universe, astronomers should see the gamma rays it produces. That evidence has so far failed to materialise Among the most dramatic events in the universe are the death of stars as they collapse into black holes and the collision of black holes themselves. These events are so violent that they […]
New Data Still Have Scientists in Dark Over Dark Matter
June 8, 2011
A dark-matter experiment deep in the Soudan mine of Minnesota now has detected a seasonal signal variation similar to one an Italian experiment has been reporting for more than a decade. The new seasonal variation, recorded by the Coherent Germanium Neutrino Technology (CoGeNT) experiment, is exactly what theoreticians had predicted if dark matter turned out […]
April 26, 2013
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