A cosmic string is a hypothetical 1-dimensional topological defect in the fabric of spacetime. 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. 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. In cosmology, a topological defect is a (often) stable configuration of matter predicted by some theories to form at phase transitions in the very early universe. ... Jump to: navigation, search This article may be too technical for most readers to understand. ... In its most common usage, the term phase change indicates that a substance has changed among the three classical phases of matter: solid, liquid and gas. ...

Cosmic strings, if they exist, would be extremely thin with diameters on the same order as a proton. They would have immense density, however, and so would represent significant gravitational sources. A cosmic string 1.6 kilometers in length would exert more gravity than the Earth. 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. Superclusters are large groups of smaller galaxy groups and clusters, and are among the largest structures of the cosmos. ...

A 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. These loops have a finite lifespan due to decay via gravitational radiation. In physics, a gravitational wave consists of energy transmitted in the form of a wave through the gravitational field of space-time. ...

Other types of topological defects in spacetime are domain walls, monopoles, and textures. A domain wall is a theoretical 2-dimensional singularity. ... In physics, magnetic monopole is a term describing a hypothetical particle that could be quickly clarified to a person familiar with magnets but not electromagnetic theory as a magnet with only one pole. In more accurate terms, it would have net magnetic charge. Interest in the concept stems from particle...

Observational evidence

Cosmic strings were once thought to be an explanation of the large scale structure of the universe, but all what is known today through galaxy surveys and precision measurements of the cosmic microwave background fits an evolution out of random, gaussian fluctations. These precison observations therefore tend to rule out a significant role of cosmic strings. Astronomy and cosmology examine the universe to understand the large-scale structure of the cosmos. ... WMAP image of the CMB anisotropy,Cosmic microwave background radiation(June 2003) The cosmic microwave background radiation (CMB) is a form of electromagnetic radiation that fills the whole of the universe. ...

A recent discovery of a "double galaxy" Capodimonte-Sternberg lens candidate 1 (CSL-1) has some interesting implications for cosmic string theory. 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 in the sky. NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 56,000 light years in diameter and approximately 60 million light years distant. ... Note: as an adjective (stressed on the second syllable instead of the first), august means honorable. ... 2003(MMIII) is a common year starting on Wednesday of the Gregorian calendar. ... The Royal Astronomical Society (RAS) began as the Astronomical Society of London in 1820 to support astronomical research (mainly carried on at the time by gentleman astronomers rather than professionals). ...

The cosmic string producing this double image should be detectable in precision measurements of the cosmic microwave background but at the spatial resolution of WMAP, the result is inconclusive. Re-examination with the PLANCK detector will decide the issue. Alternate meaning: WMAP (AM) Artist depiction of the WMAP satellite at the L2 point The Wilkinson Microwave Anisotropy Probe (WMAP) is a NASA satellite whose mission is to survey the sky to measure the temperature of the radiant heat left over from the Big Bang. ... The Planck Surveyor is the third Medium-Sized Mission (M3) of ESAs Horizon 2000 Scientific Programme. ...

A second piece of evidence supporting string theory is a phenomenon observed in observations of the "double quasar" called Q0957+561A,B. 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. The gravitational lens effect of this intermediate galaxy bends the quasar's light so that it follows two paths of different lengths to Earth. 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). This view, taken with infrared light, is a false-color image of a quasar-starburst tandem with the most luminous starburst ever seen in such a combination. ... The Twin Quasar (Double Quasar) or Old Faithful is also known as Q0957+561, or QSO 0957+561. ... Dennis Walsh was a British astronomer, born 12 June 1933 into a poor family in Manchester, England. ... Jump to: navigation, search This page refers to the year 1979. ... This article is in need of attention from an expert on the subject. ...

However, a team of astronomers at the Harvard-Smithsonian Centre for Astrophysics led by Rudolph Schild studied the quasar and found that during the period between September 1994 and July 1995 the two images appeared to have no time delay; changes in the brightness of the two images occurred simultaneously on four separate occasions. Schild and his team believe that the only explanation for this observation is that a cosmic string passed between the Earth and the quasar during that time period traveling at very high speed and oscillating with a period of about 100 days. Their findings were published in Volume 422 of Astronomy and Astrophysics in August 2004. September is the ninth month of the year in the Gregorian Calendar and one of four Gregorian months with 30 days. ... Jump to: navigation, search 1994 was a common year starting on Saturday of the Gregorian calendar, and was designated the International year of the Family. ... July is the seventh month of the year in the Gregorian Calendar and one of seven Gregorian months with the length of 31 days. ... 1995 was a common year starting on Sunday of the Gregorian calendar. ... Astronomy and Astrophysics (often referred to as A&A) is a European Journal, publishing papers on theoretical, observational and instrumental astronomy and astrophysics. ... 2004(MMIV) is a leap year starting on Thursday of the Gregorian calendar. ...

External link

• http://www.damtp.cam.ac.uk/user/gr/public/cs_interact.html
• astro-ph/0302547 CSL-1: a chance projection effect or serendipitous discovery of a gravitational lens induced by a cosmic string?
• astro-ph/0406434 Anomalous Fluctuations in Observations of Q0957+561 A,B: Smoking Gun of a Cosmic String?
• astro-ph/0410073 Cosmic strings reborn?
• astro-ph/0503120 Signatures of Cosmic Strings in the Cosmic Microwave Background
• astro-ph/0506400 Further spectroscopic observations of the CSL-1 object