CMB cold spot

[2] The radius of the "cold spot" subtends about 5°; it is centered at the galactic coordinate lII = 207.8°, bII = −56.3° (equatorial: α = 03h 15m 05s, δ = −19° 35′ 02″).

[citation needed] In the first year of data recorded by the Wilkinson Microwave Anisotropy Probe (WMAP), a region of sky in the constellation Eridanus was found to be colder than the surrounding area.

[4] Subsequently, using the data gathered by WMAP over 3 years, the statistical significance of such a large, cold region was estimated.

[5] Thus it appears unlikely, but not impossible, that the cold spot was generated by the standard mechanism of quantum fluctuations during cosmological inflation, which in most inflationary models gives rise to Gaussian statistics.

[11] Rudnick et al.[12] found a dip in NVSS galaxy number counts in the direction of the Cold Spot, suggesting the presence of a large void.

A 2017 study[19] reported surveys showing no evidence that associated voids in the line of sight could have caused the CMB Cold Spot and concluded that it may instead have a primordial origin.

[20][21] In December 2021, the Dark Energy Survey (DES), analyzing their data, put forward more evidence for the correlation between the Eridanus supervoid and the CMB cold spot.

[22][23] In late 2007, (Cruz et al.)[24] argued that the Cold Spot could be due to a cosmic texture, a remnant of a phase transition in the early Universe.

[3] Laura Mersini-Houghton said, "Standard cosmology cannot explain such a giant cosmic hole" and made the hypothesis that the WMAP cold spot is "... the unmistakable imprint of another universe beyond the edge of our own."

Existence of its counterpart, a Northern Cold Spot with almost identical randomness properties among other low-temperature regions is revealed."