Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

“Planck” Puts Einstein to the Test

05.03.2015

Data analysis of satellite mission on dark energy and theory of gravitation

Researchers, including physicists from Heidelberg University, have gained new insights into dark energy and the theory of gravitation by analysing data from the “Planck” satellite mission of the European Space Agency (ESA).

Their results demonstrate that the standard model of cosmology remains an excellent description of the universe. Yet when the Planck data is combined with other astronomical observations, several deviations emerge. Further studies must determine whether these anomalies are due to measurement uncertainties or undiscovered physical correlations, which would also challenge Einstein’s theory of gravitation. Thus, the analysis of the Planck data gives major impetus for research during future space missions.

From 2009 to 2013, the ESA’s Planck satellite took measurements of the so-called cosmic microwave background (CMB). The CMB is radiation that originated approx. 13 billion years ago, about 380,000 years after the Big Bang.

Due to the expansion of the universe, this light is still observable today at microwave wavelengths across the entire sky. Between 2009 and 2013, Planck surveyed the sky to map this ancient light in unprecedented detail. Now several research articles on the Planck data have been published. The Cosmology research group of the Institute for Theoretical Physics (ITP) at Heidelberg University participated in one of these studies.

“Precise measurements of cosmic microwave radiation reveal minute differences in temperature. On a celestial map, these temperature fluctuations look like small specks. Every speck is a region of somewhat higher or lower temperature,” explains Dr. Valeria Pettorino, junior research group leader at the ITP. Prior findings point to only six parameters that describe the development of the universe after the Big Bang with relative accuracy, using what is known as the standard model of cosmology.

The temperature differences of the cosmic microwave background have allowed researchers to identify these parameters with extreme accuracy. One of them accounts for so-called dark energy, which comprises about 70 per cent of the total energy of the universe and is responsible for its accelerated expansion.

Research into dark energy is still in its infancy. Even though the data from the cosmic microwave background shows that dark energy is required, its composition remains unclear. Using the latest satellite data, the Planck researchers have put various theories to the test that take dark energy into account and are based on modified gravitation – and hence also call into question the theory of gravitation postulated in Albert Einstein’s theory of relativity.

They employed a broad spectrum of methods and other measurement data, including Baryonic Acoustic Oscillations, which are density waves from the early universe, local measurements of the Hubble constant, which specifies the universe’s rate of expansion at the present day, as well as a certain group of supernovae or exploding stars.

From the Planck data the scientists were able to determine just how much dark energy existed in the past. “Surprisingly, the amount of early dark energy was significantly less than we expected. So far, it had been assumed that dark energy comprised a maximum of one per cent of all energy at the time the microwave background radiation was released. But the new Planck results indicate that it could have been no more than 0.4 per cent,” explains Dr. Pettorino. “That’s a big problem for the theoretical models of dark energy which predicted a considerably higher amount of energy for the early universe,” adds Dr. Matteo Martinelli, postdoc at the ITP.

Furthermore, the analysis of the Planck data also revealed small disruptions in gravity itself that are not completely consistent with the standard model of cosmology. Even though these deviations are tiny and vary depending on the dataset studied, they call for further testing and investigation with other sets of data. “Further study might enable us to find out whether we are really dealing with deviations from Einstein’s law of gravity that require a return to the drawing board,” says Valeria Pettorino.

According to the physicist, the analyses are of key importance to cosmological research on dark energy and gravitation. They can give invaluable impetus to upcoming satellite missions, such as the 2020 Euclid mission planned by the ESA and NASA. The astronomical institutes of Heidelberg University will again be major participants in this mission.

Original publication:
Planck 2015 results. XIV. Dark energy and modified gravity.
http://www.cosmos.esa.int/documents/387566/522789/Planck_2015_Results_XIV_Dark_E...

Contact:
Dr. Valeria Pettorino
Institute for Theoretical Physics
Phone +49 6221 54-9414
v.pettorino@thphys.uni-heidelberg.de

Communications and Marketing
Press Office
Phone +49 6221 54-2311
presse@rektorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw - Informationsdienst Wissenschaft

More articles from Physics and Astronomy:

nachricht Seeing the quantum future... literally
16.01.2017 | University of Sydney

nachricht Airborne thermometer to measure Arctic temperatures
11.01.2017 | Moscow Institute of Physics and Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>