Tag Archives: dark matter

BOSS Quasars Unveil a New Era in the Expansion History of the Universe

Berkeley Lab scientists and their Sloan Digital Sky Survey colleagues use quasars to probe dark energy over 10 billion years in the past

BOSS, the Baryon Oscillation Spectroscopic Survey, is mapping a huge volume of space to measure the role of dark energy in the evolution of the universe. BOSS is the largest program of the third Sloan Digital Sky Survey (SDSS-III) and has just announced the first major result of a new mapping technique, based on the spectra of over 48,000 quasars with redshifts up to 3.5, meaning that light left these active galaxies up to 11.5 billion years in the past.

“No technique for dark energy research has been able to probe this ancient era before, a time when matter was still dense enough for gravity to slow the expansion of the universe, and the influence of dark energy hadn’t yet been felt,” says BOSS principal investigator David Schlegel, an astrophysicist in the Physics Division of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). “In our own time, expansion is accelerating because the universe is dominated by dark energy. How dark energy effected the transition from deceleration to acceleration is one of the most challenging questions in cosmology.” (more…)

Read More

What’s Happening with the Higgs Boson

Berkeley Lab scientists, major contributors to the ATLAS experiment at the Large Hadron Collider, explain what the excitement is about

CERN, the European Organization for Nuclear Research headquartered in Geneva, Switzerland, will hold a seminar early in the morning on July 4 to announce the latest results from ATLAS and CMS, two major experiments at the Large Hadron Collider (LHC) that are searching for the Higgs boson. Both experimental teams are working down to the wire to finish analyzing their data, and to determine exactly what can be said about what they’ve found.

“We do not yet know what will be shown on July 4th,” says Ian Hinchliffe, a theoretical physicist in the Physics Division at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), who heads the Lab’s participation in the ATLAS experiment. “I have seen many conjectures on the blogs about what will be shown: these are idle speculation. Things are moving very fast this week, and it’s an exciting time at CERN. Many years of hard work are coming to fruition.” (more…)

Read More

The Search for Dark Matter Goes Deeper Underground

With LUX ZEPLIN Berkeley Lab researchers seek to increase the sensitivity of LUX, the most sensitive search for dark matter yet, by orders of magnitude

Although it’s invisible, dark matter accounts for at least 80 percent of the matter in the universe. No one knows what it is, but most scientists would bet on weakly interacting massive particles, or WIMPs. (more…)

Read More

Planck All-Sky Images Show Cold Gas and Strange Haze

New images from the Planck mission show previously undiscovered islands of star formation and a mysterious haze of microwave emissions in our Milky Way galaxy. The views give scientists new treasures to mine and take them closer to understanding the secrets of our galaxy.

Planck is a European Space Agency mission with significant NASA participation. (more…)

Read More

Physicists Set Strongest Limit on Mass of Dark Matter

Brown University physicists have set the strongest limit for the mass of dark matter, the mysterious particles believed to make up nearly a quarter of the universe. The researchers report in Physical Review Letters that dark matter must have a mass greater than 40 giga-electron volts. The distinction is important because it casts doubt on recent results from underground experiments that have reported detecting dark matter

PROVIDENCE, R.I. [Brown University] — If dark matter exists in the universe, scientists now have set the strongest limit to date on its mass. (more…)

Read More

NASA Telescope Helps Confirm Nature of Dark Energy

PASADENA, Calif. — A five-year survey of 200,000 galaxies, stretching back seven billion years in cosmic time, has led to one of the best independent confirmations that dark energy is driving our universe apart at accelerating speeds. The survey used data from NASA’s space-based Galaxy Evolution Explorer and the Anglo-Australian Telescope on Siding Spring Mountain in Australia.

The findings offer new support for the favored theory of how dark energy works — as a constant force, uniformly affecting the universe and propelling its runaway expansion. They contradict an alternate theory, where gravity, not dark energy, is the force pushing space apart. According to this alternate theory, with which the new survey results are not consistent, Albert Einstein’s concept of gravity is wrong, and gravity becomes repulsive instead of attractive when acting at great distances. (more…)

Read More

Search for Dark Matter Narrowed by New Data From XENON100

*Collaboration reveals results from 100-day experiment*

Today, scientists from the XENON collaboration announced the result from their search for the elusive component of our universe known as dark matter. After analyzing one hundred days of data taken with the XENON100 experiment, they see no evidence for the existence of Weakly Interacting Massive Particles (WIMPs), the leading candidates for the mysterious dark matter. The XENON100 experiment is operated deep underground at the Gran Sasso National Laboratory of the Italian National Institute for Physics (INFN). (more…)

Read More

Herschel Measures Dark Matter for Star-Forming Galaxies

PASADENA, Calif. — The Herschel Space Observatory has revealed how much dark matter it takes to form a new galaxy bursting with stars. Herschel is a European Space Agency cornerstone mission supported with important NASA contributions.

The findings are a key step in understanding how dark matter, an invisible substance permeating our universe, contributed to the birth of massive galaxies in the early universe. (more…)

Read More