PSU: Mysterious Radio Signals Test General Relativity

bystander · Post by **bystander** » Thu Dec 31, 2015 5:48 pm

Mysterious Radio Signals from Space are a Much Better Test of Einstein's General Relativity
Penn State University | via EurekAlert | 2015 Dec 30

This illustration shows how two photons, one at a high frequency (nu_h) and another at a low frequency (nu_l), travel in curved space-time from their origin in a distant Fast Radio Burst (FRB) source until reaching the Earth. A lower-limit estimate of the gravitational pull that the photons experience along their way is given by the mass in the center of the Milky Way Galaxy. Credit: Purple Mountain Observatory, Chinese Academy of Sciences
A new way to test one of the basic principles underlying Einstein's theory of General Relativity using brief blasts of rare radio signals from space called Fast Radio Bursts is ten times, to one-hundred times better than previous testing methods that used gamma-ray bursts, according to a paper just published in the journal Physical Review Letters. The paper received additional highlighting as an "Editor's Suggestion" due to "its particular importance, innovation, and broad appeal," according to the journal's editors.

The new method is considered to be a significant tribute to Einstein on the 100th anniversary of his first formulation of the Equivalence Principle, which is a key component of Einstein's theory of General Relativity. More broadly, it also is a key component of the concept that the geometry of spacetime is curved by the mass density of individual galaxies, stars, planets, and other objects.

Fast Radio Bursts are super-brief blasts of energy -- lasting just a few milliseconds. Until now, only about a dozen Fast Radio Bursts have been detected on Earth. They appear to be caused by mysterious events beyond our Milky Way Galaxy, and possibly even beyond the Local Group of galaxies that includes the Milky Way. The new technique will be important for analyzing the abundance of observations of Fast Radio Bursts that advanced radio-signal observatories, now being planned, are expected to detect. ...

Testing Einstein's Equivalence Principle with Fast Radio Bursts - Jun-Jie Wei et al

Physical Review Letters 115:261101 (31 Dec 2015) DOI: 10.1103/PhysRevLett.115.261101
arXiv.org > astro-ph > arXiv:1512.07670 > 24 Dec 2015