Several possible scenarios are possible depending on the properties of dark energy; one is that the Universe will end in a so-called big rip. This interesting topic was recently explored by five researchers from the University of Science and Technology of China, the Institute of Theoretical Physics at the Chinese Academy of Sciences, Northeastern University, and Peking University. Their work, entitled "Dark energy and fate of the Universe", was published in Sci China-Phys Mech Astron 2012, Vol. 55 No. 7.
For millennia, human beings have been pondering two ultimate questions: "Where do we come from?" and "Where are we going?" Over that time, these questions have spurred theological and philosophical debate. Thanks to the rapid development of modern cosmology in the past three decades, scientists nowadays have obtained some important clues to answer these questions. The standard "inflation + hot big bang" framework has been developed to explain the origin of the Universe. However, to forecast the destiny of the Universe, researchers have realized that the nature of dark energy is key.In the absence of a consensus on what dark energy is, a phenomenological description of the equation-of-state parameter w—the ratio of pressure and density of dark energy—provides an important means for investigating dark energy dynamics. Properties of dark energy will decide the ultimate fate of the Universe. In particular, if w
To foresee that fate, it is important to choose an appropriate parameterization that covers the overall expansion history of the Universe. The most popular Chevallier-Polarski-Linder (CPL) parameterization, in fact, is not suitable in predicting the future evolution of the Universe because in this form w will diverge when the redshift parameter approaches -1. Thus, the authors invoke a divergence-free parameterization, called the Ma-Zhang (MZ) parameterization, to predict the evolution of the Universe.
One of the more intriguing questions is: "If a doomsday exists, how far are we from it?" After constraining the MZ parameter space via a Markov Chain Monte Carlo method, the authors found that by using the current observational data tBR – t0 = 103.5 Gyr for the best-fit result, and tBR – t0 = 16.7 Gyr at the 95.4% confidence level (CL) lower limit. Here tBR denotes the time of the big rip, and t0 denotes the present day. "In other words, at worst (95.4% CL), the time remaining before the Universe ends in a big rip is 16.7 Gyr", said the authors.Thus the constrained parameter space indicates that it is very likely that in the future w
However, from what we already know of the dynamical properties of dark energy, one thing is all very clear, we still have a very long future ahead.
See the article: http://phys.scichina.com:8084/Jwk_sciG_en/EN/abstract/abstract506891.shtml#
Zhang Xin | EurekAlert!
Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore
Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Information Technology
05.12.2016 | Earth Sciences