Cosmic string constraints from WMAP and the South Pole Telescope data

Dvorkin, Cora; Wyman, Mark; Hu, Wayne

doi:10.1103/physrevd.84.123519

Cited by 79 publications

(79 citation statements)

References 66 publications

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“…The differences between the upper limits for the NAMBU and AHmimic models is compatible with those seen previously using WMAP 7-year and SDSS data . The upper limits from this version of the Planck likelihood are better than those computed from WMAP7+SPT (Dvorkin et al 2011) and WMAP7+ACT (Dunkley et al 2011) and are significantly better than those from WMAP7+SDSS . Based on the Planck "Blue Book" values for noise levels we predicted (Battye et al 2008) a limit of Gµ/c 2 < 6×10 −8 , while the present limit is about a factor of two worse than this.…”

Section: Power Spectrum Constraints On Cosmic Strings and Other Topolmentioning

confidence: 87%

“…These WMAP constraints can be improved by adding small-scale CMB anisotropy in a joint analysis. The Nambu-Goto strings limit improves to become Gµ/c 2 < 1.7 × 10 −7 (using SPT data, Dvorkin et al 2011) and field theory strings yield Gµ AH /c 2 < 4.2 × 10 −7 (Urrestilla et al 2011). Power-spectrum based constraints on global textures were studied in Bevis et al (2004) and , with the latter paper giving a 95% limit of Gµ/c 2 < 4.5 × 10 −6 .…”

Section: Introductionmentioning

confidence: 99%

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Planck2013 results. XXV. Searches for cosmic strings and other topological defects

Ade¹,

Aghanim²,

Armitage-Caplan³

et al. 2014

A&A

278

191

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Planck data have been used to provide stringent new constraints on cosmic strings and other defects. We describe forecasts of the CMB power spectrum induced by cosmic strings, calculating these from network models and simulations using line-of-sight Boltzmann solvers. We have studied Nambu-Goto cosmic strings, as well as field theory strings for which radiative effects are important, thus spanning the range of theoretical uncertainty in the underlying strings models. We have added the angular power spectrum from strings to that for a simple adiabatic model, with the extra fraction defined as f 10 at multipole = 10. This parameter has been added to the standard six parameter fit using COSMOMC with flat priors. For the Nambu-Goto string model, we have obtained a constraint on the string tension of Gµ/c 2 < 1.5 × 10 −7 and f 10 < 0.015 at 95% confidence that can be improved to Gµ/c 2 < 1.3 × 10 −7 and f 10 < 0.010 on inclusion of high-CMB data. For the Abelian-Higgs field theory model we find, Gµ AH /c 2 < 3.2 × 10 −7 and f 10 < 0.028. The marginalised likelihoods for f 10 and in the f 10 -Ω b h 2 plane are also presented. We have additionally obtained comparable constraints on f 10 for models with semilocal strings and global textures. In terms of the effective defect energy scale these are somewhat weaker at Gµ/c 2 < 1.1 × 10 −6 . We have made complementarity searches for the specific non-Gaussian signatures of cosmic strings, calibrating with all-sky Planck resolution CMB maps generated from networks of post-recombination strings. We have validated our non-Gaussian searches using these simulated maps in a Planck-realistic context, estimating sensitivities of up to ∆Gµ/c 2 ≈ 4 × 10 −7 . We have obtained upper limits on the string tension at 95% confidence of Gµ/c 2 < 9.0 × 10 −7 with modal bispectrum estimation and Gµ/c 2 < 7.8 × 10 −7 for real space searches with Minkowski functionals. These are conservative upper bounds because only post-recombination string contributions have been included in the non-Gaussian analysis.

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Section: Power Spectrum Constraints On Cosmic Strings and Other Topolmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Planck2013 results. XXV. Searches for cosmic strings and other topological defects

Ade¹,

Aghanim²,

Armitage-Caplan³

et al. 2014

A&A

278

191

View full text Add to dashboard Cite

show abstract

“…String tensions this large have already been excluded through directly limiting a string contribution to the CMB power spectrum [33,[46][47][48][49], Gµ 10 −6 − 10 −7 . However, for lower reconnection probability, e.g.…”

Section: Resultsmentioning

confidence: 99%

Improved limits on short-wavelength gravitational waves from the cosmic microwave background

Sendra

Smith

2012

Phys. Rev. D

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The cosmic microwave background (CMB) is affected by the total radiation density around the time of decoupling. At that epoch, neutrinos comprised a significant fraction of the radiative energy, but there could also be a contribution from primordial gravitational waves with frequencies greater than ∼ 10 −15 Hz. If this cosmological gravitational wave background (CGWB) were produced under adiabatic initial conditions, its effects on the CMB and matter power spectrum would mimic massless non-interacting neutrinos. However, with homogenous initial conditions, as one might expect from certain models of inflation, pre big-bang models, phase transitions and other scenarios, the effect on the CMB would be distinct. We present updated observational bounds for both initial conditions using the latest CMB data at small scales from the South Pole Telescope (SPT) in combination with Wilkinson Microwave Anisotropy Probe (WMAP), current measurements of the baryon acoustic oscillations, and the Hubble parameter. With the inclusion of the data from SPT the adiabatic bound on the CGWB density is improved by a factor of 1.7 to 10 6 Ωgwh 2 8.7 at the 95% confidence level (C. L.), with weak evidence in favor of an additional radiation component consistent with previous analyses. The constraint can be converted into an upper limit on the tension of horizon-sized cosmic strings that could generate this gravitational wave component, with Gµ 2 × 10 −7 at 95% C. L., for string tension Gµ. The homogeneous bound improves by a factor of 3.5 to 10 6 Ωgwh 2 1.0 at 95% C. L., with no evidence for such a component from current data.

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“…Cosmic strings can produce various observational phenomena, such as CMB anisotropies [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], CMB spectral distortions [19,20], early large scale structure formations [21][22][23][24][25], early reionization [26][27][28][29] and gravitational waves [30][31][32][33][34][35][36][37]. Since most observational effects due to strings are gravitational, we can set observational constraints on the strength of gravitational interactions of strings which is parametrized by the dimensionless number Gµ, where G is Newton's constant and µ is the mass per unit length (or tension) of string.…”

Section: Introductionmentioning

confidence: 99%

“…The current limit on Gµ is obtained from CMB anisotropy observations. WMAP and SPT data provide the limit Gµ < 1.7 × 10 −7 [16]. Recently Planck data updated the limit to Gµ < 1.5 × 10 −7 [18].…”

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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Cosmic string constraints from WMAP and the South Pole Telescope data

Cited by 79 publications

References 66 publications

Planck2013 results. XXV. Searches for cosmic strings and other topological defects

Planck2013 results. XXV. Searches for cosmic strings and other topological defects

Improved limits on short-wavelength gravitational waves from the cosmic microwave background

21 cm angular spectrum of cosmic string loops

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