Subscribe free to our newsletters via your
. 24/7 Space News .


Subscribe free to our newsletters via your




















TIME AND SPACE
The expansion of the universe simulated
by Staff Writers
Geneva, Switzerland (SPX) Mar 10, 2016


The gravitational waves generated during the formation of structures in the universe are shown. The structures (distribution of masses) are shown as bright dots, gravitational waves by ellipses. The size of the ellipse is proportional to the amplitude of the wave and its orientation represents its polarization. Image courtesy Ruth Durrer, UNIGE. For a larger version of this image please go here.

The Universe is constantly expanding. It changes, creating new structures that merge. But how does our Universe evolve? Physicists at the University of Geneva (UNIGE), Switzerland, have developed a new code of numerical simulations that offers a glimpse of the complex process of the formation of structures in the Universe.

Based on Einstein's equations, they were able to integrate the rotation of space-time into their calculations and calculate the amplitude of gravitational waves, whose existence was confirmed for the first time on February 12, 2016. This study is published in the journal Nature Physics.

Until now, scientists studied the formation of large-scale cosmological structures based numerical simulations of Newtonian gravitation. These codes postulate that space itself does not change, it is said to be static, while time goes on.

The simulations that it allows are very precise if the matter in the Universe moves slowly (i.e., about 300 km per second). However, when the matter particles move at high speed, this code only allows approximate calculations.

Furthermore, it does not describe the fluctuations of dark energy. Constituting 70% of the total energy of the Universe (the remaining 30% is made of dark matter and ordinary matter), it is responsible for the accelerated expansion of the Universe. Therefore, it was necessary to find a new way to simulate the formation of cosmological structures and allow the study of these two phenomena.

The theory of general relativity applied
Ruth Durrer's team from the Department of Theoretical Physics in the Faculty of Science at UNIGE, has thus created a code, named gevolution, based on Einstein's Theory of general relativity.

Indeed, general relativity considers space-time as being dynamical, that is to say that space and time are constantly changing, unlike the static space of Newtonian theory. The goal was to predict the amplitude and the impact of gravitational waves and frame-dragging (the rotation of space-time) induced by the formation of cosmological structures.

To do so, the physicists from UNIGE analysed a cubic portion in space, consisting of 60 billion zones with each containing a particle (that is to say, a portion of a galaxy), in order to study the way they move with respect to their neighbors.

Thanks to the LATfield2 library (developed by David Daverio from UNIGE), which solves nonlinear partial differential equations, and the Supercomputer from the Swiss Supercomputer Center in Lugano, the researchers were able to study the motion of particles and calculate the metric (the measure of distances and time between two galaxies in the Universe) using Einstein's equations.

The resulting spectra of these calculations allow to quantify the difference between the results obtained by gevolution and those coming from Newtonian codes. This allows to measure the effect of frame-dragging and gravitational waves introduced by the formation of structure in the Universe.

Gravitational waves and frame-dragging predicted by gevolution
Indeed, frame-dragging and gravitational waves have never been included in simulations until the creation of the gevolution code. This opens the way for the comparison of simulation results of the evolution of the Universe with observations. With their new code, the physicists at UNIGE will be able to test the theory of general relativity on much larger scales than at present.

In order to open research to a maximum in this field, Professor Ruth Durrer and her team will make their gevolution code public. Perhaps soon light will be shed on the mysteries of dark energy.

.


Related Links
Universite de Geneve
Understanding Time and Space






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
TIME AND SPACE
Smoking Gun Uncovering Secret of Cosmic Bullets
Bonn, Germany (SPX) Mar 03, 2016
LOFAR, the low-frequency array radio telescope, normally receives weak radio waves from the distant universe. But now and then an ultra-short, bright radio pulse is observed somewhere in between AM and FM radio frequencies. This radio blast would appear as a short cracking sound in your car radio. While usually ignored, this radio signal is actually the last SOS of an elementary particle enterin ... read more


TIME AND SPACE
China to use data relay satellite to explore dark side of moon

NASA May Return to Moon, But Only After Cutting Off ISS

Lunar love: When science meets artistry

New Lunar Exhibit Features NASA's Lunar Reconnaissance Orbiter Imagery

TIME AND SPACE
Great tilt gave Mars a new face

Space simulation crew hits halfway mark til August re-entry

Proton-M carrier rocket assembled ahead of Mars Mission

Monster volcano gave Mars extreme makeover: study

TIME AND SPACE
First tomatoes, peas harvested from mock Martian farm

Sore, but no taller, astronaut Scott Kelly adjusts to Earth

Test Dummies to Help Assess Crew Safety in Orion

Commercial Crew: Building in Safety from the Ground Up in a Unique Way

TIME AND SPACE
Aim Higher: China Plans to Send Rover to Mars in 2020

China's lunar probe sets record for longest stay

China's ambition after space station

Sky is the limit for China's national strategy

TIME AND SPACE
International Space Station's '1-year crew' returns to Earth

Scott Kelly and Mikhail Kornienko return to Earth after One-Year Mission

Paragon wins NASA ISS water processor development contract

NASA's Science Command Post Supports Scott Kelly's Year In Space

TIME AND SPACE
SpaceX launches SES-9 satellite to GEO; but booster landing fails

US Space Company in Talks With India to Launch Satellite

Ariane 5 launch contributes to Ariane 6 development

At last second, SpaceX delays satellite launch again

TIME AND SPACE
Evidence found for unstable heavy element at solar system formation

Imaging Technique May Help Discover Earth-Like Planets Around Other Stars

Newly discovered planet in the Hyades cluster could shed light on planetary evolution

Imaging technique may help discover Earth-like planets

TIME AND SPACE
Electron-beam imaging can see elements that are 'invisible' to common methods

New radar system set for testing

Scaling up tissue engineering

UMass Amherst team offers new, simpler law of complex wrinkle patterns




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News








The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.