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 Tune your radio: galaxies sing while forming stars
21.02.2017 | Max-Planck-Institut für Radioastronomie

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>