Angular 21 cm power spectrum of a scaling distribution of cosmic string wakes

Hernández, Oscar F.; Wang, Yi; Brandenberger, Robert H.; Fong, Jenna E.

doi:10.1088/1475-7516/2011/08/014

Cited by 27 publications

(43 citation statements)

References 45 publications

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“…Even at a reduced amplitude, strings remain interesting to study. They could, for instance, be a source of observable B-mode polarization [12][13][14][15][16][17], gravitational waves [18][19][20], 21 cm radiation [21][22][23][24] or gravitational lensing [25,26]. A definitive detection of strings would greatly narrow down the inflationary parameter space and could be the only direct observational window into the very high energy physics that generates strings.…”

Section: Introductionmentioning

confidence: 99%

Cosmic string constraints from WMAP and the South Pole Telescope data

Dvorkin

Wyman

2011

Phys. Rev. D

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The predictions of the inflationary ΛCDM paradigm match today's high-precision measurements of the cosmic microwave background anisotropy extremely well. The same data put tight limits on other sources of anisotropy. Cosmic strings are a particularly interesting alternate source to constrain. Strings are topological defects, remnants of inflationary-era physics that persist after the big bang. They are formed in a variety of models of inflation, including string theory models such as brane inflation. We assume a "Nambu-Goto" model for strings, approximated by a collection of unconnected segments with zero width, and show that measurements of temperature anisotropy by the South Pole Telescope break a parameter degeneracy in the WMAP data, permitting us to place a strong upper limit on the possible string contribution to the CMB anisotropy: the power sourced by zero-width strings must be < 1.75% (95% CL) of the total or the string tension Gµ < 1.7 × 10 −7 . These limits imply that the best hope for detecting strings in the CMB will come from B-mode polarization measurements at arcminute scales rather than the degree scale measurements pursued for gravitational wave detection.

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Section: Introductionmentioning

confidence: 99%

Cosmic string constraints from WMAP and the South Pole Telescope data

Dvorkin

Wyman

2011

Phys. Rev. D

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“…[45]. Therefore, the angular power spectrum of 21 cm fluctuations can give the limit on Gµ by measuring the spectrum due to loops.…”

Section: Discussionmentioning

confidence: 99%

“…Cosmological 21 cm signatures due to cosmic strings have been investigated in several papers [42][43][44][45][46]. It is wellknown that a cosmic string produces overdense regions by inducing gravitational collapse of baryons onto the string wake.…”

Section: Introductionmentioning

confidence: 99%

21 cm angular spectrum of cosmic string loops

Tashiro

2013

Phys. Rev. D

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The 21 cm signatures induced by moving cosmic string loops are investigated. Moving cosmic string loops seed filamentary nonlinear objects. We analytically evaluate the differential 21 cm brightness temperature from these objects. We show that the brightness temperature reaches 200 mK for a loop whose tension is about the current upper limit, Gµ ∼ 10 −7 . We also calculate the angular power spectrum, assuming scaling in loop distribution. We find that the angular power spectrum for Gµ > 10 −8 at z = 30 or Gµ > 10 −10 at z = 20 can dominate the spectrum of the primordial density fluctuations. Finally we show that a future SKA-like observation has the potential to detect the power spectrum due to loops with Gµ = 10 −8 at z = 20.

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“…This computation of Delta can now be applied to either condition (17) or (18). For example, using the "Local delta condition" (18), we find that the disruption redshift, the redshift when ∆(k 3 (z), z) = 1 depends only logarithmically on the wake thickness and hence on the value of Gµ.…”

Section: Local Delta Conditionmentioning

confidence: 99%

“…Whereas overall cosmic strings are a sub-dominant component to structure formation, string wakes can nevertheless give rise to prominent signatures in position space maps. They give rise to a network of edges in CMB temperature maps across which the temperature jumps [8], rectangles in the sky with a specific CMB polarization signal (statistically equal E-mode and B-mode polarization with a polarization angle which is uniform over the rectangle and whose amplitude has a linear gradient [16]), and thin wedges of extra absorption or emission in 21cm redshift maps [17] (see also [12,18]). These features are most prominent at high redshifts when string wakes are already nonlinear fluctuations but the Gaussian fluctuations are still in their linear regime.…”

Section: Introductionmentioning

confidence: 99%

Disruption of cosmic string wakes by Gaussian fluctuations

2016

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We study the stability of cosmic string wakes against the disruption by the dominant Gaussian fluctuations which are present in cosmological models. We find that for a string tension given by Gµ = 10 −7 wakes remain locally stable until a redshift of z = 6, and for a value of Gµ = 10 −14they are stable beyond a redshift of z = 20. We study a global stability criterion which shows that wakes created by strings at times after teq are identifiable up to the present time, independent of the value of Gµ. Taking into account our criteria it is possible to develop strategies to search for the distinctive position space signals in cosmological maps which are induced by wakes.

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Angular 21 cm power spectrum of a scaling distribution of cosmic string wakes

Abstract: Cosmic string wakes lead to a large signal in 21 cm redshift maps at redshifts larger than that corresponding to reionization. Here, we compute the angular power spectrum of 21 cm radiation as predicted by a scaling distribution of cosmic strings whose wakes have undergone shock heating.

Cited by 27 publications

References 45 publications

Cosmic string constraints from WMAP and the South Pole Telescope data

Cosmic string constraints from WMAP and the South Pole Telescope data

21 cm angular spectrum of cosmic string loops

Disruption of cosmic string wakes by Gaussian fluctuations

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