January 10, 2013
The ‘New Physics’ Model of Dark Energy Nixed
Last month, a group of European astronomers, using a massive radio telescope in Germany, made the most accurate measurement of the proton-to-electron mass ratio ever accomplished and found that there has been no change in the ratio to one part in 10 million at a time when the universe was about half its current age, around 7 billion years ago. When University of Arizona astronomy professor Rodger Thompson put this new measurement into his calculations, he found that it excluded almost all of the dark energy models using the commonly expected values or parameters.
The research Thompson completed showed that a popular alternative to Albert Einstein’s theory for the acceleration of the expansion of the universe does not fit newly obtained data on a fundamental constant, the proton to electron mass ratio. Thompson’s findings, reported Jan. 9 at the American Astronomical Society meeting in Long Beach, Calif., impact our understanding of the universe and point to a new direction for the further study of its accelerating expansion.
To explain the acceleration of the expansion of the universe, astrophysicists have invoked dark energy – a hypothetical form of energy that permeates all of space. A popular theory of dark energy, however, does not fit new results on the value of the proton mass divided by the electron mass in the early universe.
Thompson computed the predicted change in the ratio by the dark energy theory (generally referred to as rolling scalar fields) and found it did not fit the new data. UA alumnus Brian Schmidt, along with Saul Perlmutter and Adam Reiss, won the 2011 Nobel Prize in Physics for showing that the expansion of the universe is accelerating rather than slowing down as previously thought. The acceleration can be explained by reinstating the “cosmological constant” into Einstein’s theory of General Relativity.
Read more: The 'New Physics' Model of Dark Energy Nixed — Daily Galaxy.