Lumps in the throat

Dasgupta, Keshav; Firouzjahi, Hassan; Gwyn, Rhiannon

doi:10.1088/1126-6708/2007/04/093

Cited by 22 publications

(31 citation statements)

References 74 publications

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“…Two examples that have attracted considerable interest are semilocal strings [10][11][12] and cosmic necklaces [13]. For the latter these claims have been made both in the context of brane inflation [14][15][16] and in string theory itself [17,18]. This is the third report on an ongoing project which is addressing some of these issues.…”

Section: Introductionmentioning

confidence: 93%

Evolution of cosmic necklaces and lattices

Martins

2010

Phys. Rev. D

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Previously developed analytic models for the evolution of cosmic string and monopole networks are applied to networks of monopoles attached to two or more strings; the former case is usually known as cosmic necklaces. These networks are a common consequence of models with extra dimensions such as brane inflation. Our quantitative analysis agrees with (and extends) previous simpler estimates, but we will also highlight some differences. A linear scaling solution is usually the attractor solution for both the radiation and matter-dominated epochs, but other scaling laws can also exist, depending on the universe's expansion rate and the network's energy loss mechanisms.

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Section: Introductionmentioning

confidence: 93%

Evolution of cosmic necklaces and lattices

Martins

2010

Phys. Rev. D

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“…The power of these constraints would be reduced if the strings could be made unstable. This is the basic motivation behind semilocal strings: a duplication of the complex scalar field φ in the Abelian-Higgs action (4), occurring naturally in a range of inflation models (Urrestilla et al 2004;Dasgupta et al 2004Dasgupta et al , 2007Achucarro et al 2006), transforms the stable cosmic strings into non-topological semilocal strings (Vachaspati & Achucarro 1991) as the vacuum manifold becomes S 3 , which is simply-connected. The existence and stability of the semilocal strings is thus a question of dynamics rather than due to the topology of the vacuum manifold.…”

Section: Semi-local Stringsmentioning

confidence: 99%

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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“…(10); and (b) one imposes the two charge conservation conditions (18) and (23). An immediate corollary of this is that p; q strings meeting at a junction automatically satisfy the triangle inequalities between the i , namely i 0.…”

Section: Constraints On P; Q-string Junction Formationmentioning

confidence: 99%

Collision of cosmic superstrings

et al. 2008

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We study the formation of three-string junctions between p; q-cosmic superstrings, and collisions between such strings and show that kinematic constraints analogous to those found previously for collisions of Nambu-Goto strings apply here too, with suitable modifications to take account of the additional requirements of flux conservation. We examine in detail several examples involving collisions between strings with low values of p and q, and also examine the rates of growth or shrinkage of strings at a junction. Finally, we briefly discuss the formation of junctions for strings in a warped space, specifically with a Klebanov-Strassler throat, and show that similar constraints still apply with changes to the parameters taking account of the warping and the background flux.

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Lumps in the throat

Cited by 22 publications

References 74 publications

Evolution of cosmic necklaces and lattices

Evolution of cosmic necklaces and lattices

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

Collision of cosmic superstrings

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