A theory of a spot

Journal Article · Sat Jan 01 04:00:00 EST 2011 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2011/01/019· OSTI ID:22275267

Afshordi, Niayesh ^[1]; Slosar, Anže ^[2]; Wang, Yi ^[3]

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1. Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada)
2. Building 510A, Brookhaven National Laboratory, Upton, NY 11973 (United States)
3. Physics Department, McGill University, 3600 rue University, Montreal, H3A 2T8 (Canada)

We present a simple inflationary scenario that can produce arbitrarily large spherical underdense or overdense regions embedded in a standard Λ cold dark matter paradigm, which we refer to as bubbles. We analyze the effect such bubbles would have on the Cosmic Microwave Background (CMB). For super-horizon sized bubble in the vicinity of the last scattering surface, a signal is imprinted onto CMB via a combination of Sach-Wolfe and an early integrated Sach-Wolfe (ISW) effects. Smaller, sub-horizon sized bubbles at lower redshifts (during matter domination and later) can imprint secondary anisotropies on the CMB via Rees-Sciama, late-time ISW and Ostriker-Vishniac effects. Our scenario, and arguably most similar inflationary models, produce bubbles which are over/underdense in potential: in density such bubbles are characterized by having a distinct wall with the interior staying at the cosmic mean density. We show that such models can potentially, with only moderate fine tuning, explain the cold spot, a non-Gaussian feature identified in the Wilkinson Microwave Anisotropy Probe (WMAP) data by several authors. However, more detailed comparisons with current and future CMB data are necessary to confirm (or rule out) this scenario.

• OSTI ID: 22275267
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 01 Vol. 2011; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANISOTROPY
BUBBLES
COMPARATIVE EVALUATIONS
COSMOLOGICAL CONSTANT
COSMOLOGY
DENSITY
INFLATIONARY UNIVERSE
NONLUMINOUS MATTER
POTENTIALS
RED SHIFT
RELICT RADIATION
SCATTERING
SPHERICAL CONFIGURATION