![]() ![]() The result is that we see two images of the same quasar, one arriving a short time after the other (about 417.1 days later). The gravitational lens effect of this intermediate galaxy bends the quasar's light so that it follows two paths of different lengths to Earth. Originally discovered by Dennis Walsh, Bob Carswell, and Ray Weymann in 1979, the double image of this quasar is caused by a galaxy positioned between it and the Earth. Testa.Ī second piece of evidence supporting string theory is a phenomenon observed in observations of the "double quasar" called Q0957+561A,B. If the lensing by a cosmic string should be confirmed, it would provide the first measurements of energy scale of symmetry breaking and of the energy scale of grand unified theory."Īuthors of the paper also included: J. We propose an experimentum crucis to disentangle these two possible explanations. Extensive modelling shows in fact that cosmic strings are the only type of lens which (at least at low angular resolution) can produce undistorted double images of a background source. It can be interpreted either as the chance alignment of two identical galaxies at z= 0.46 or as the first case of gravitational lensing by a cosmic string. 1 is an extragalactic double source detected in the Osservatorio Astronomico di Capodimonte – Deep Field. In an article entitled "CSL-1: chance projection effect or serendipitous discovery of a gravitational lens induced by a cosmic string?" published in August 2003 in Volume 343, Issue 2 of "Monthly Notices of the Royal Astronomical Society," a group led by Mikhail Sazhin reported the accidental discovery of two seemingly identical galaxies very close together on the sky.įrom the abstract: "The Capodimonte–Sternberg–Lens candidate no. Other types of topological defects in spacetime are domain walls, monopoles, and textures.Ī recent discovery of a "double galaxy" has some interesting implications for cosmic string theory. Today precison observations of the large scale structure of the universe, directly using sky survey, or indirectly from observing the cosmic microwave background tend to rule out a significant role of cosmic strings. These loops have a finite lifespan due to decay via gravitational radiation. ![]() Cosmic strings would form a network of loops in the early universe, and their gravity could have been responsible for the original clumping of matter into galactic superclusters.Ī cosmic string's vibrations, which are thought to oscillate near the speed of light, can cause part of the string to pinch off into an isolated loop. A cosmic string 1.6 kilometers in length would exert more gravity than the Earth. ![]() They would have immense density, however, and so would represent significant gravitational sources. This is somewhat analogous to the boundaries that form between crystal grains in solidifying liquids, or the cracks that form when water freezes into ice.Ĭosmic strings, if they exist, would be extremely thin with diameters on the same order as a proton. ![]() Cosmic strings are hypothesized to form when different regions of spacetime undergo phase changes, resulting in domain boundaries between the two regions when they meet. A cosmic string is a hypothetical 1-dimensional topological defect in the fabric of spacetime. ![]()
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