Planck 2013 results. XXV. Searches for cosmic strings and other topological defects
Ade, P. A. R.
Battaner López, Eduardo
Planck Collaboration
Cosmic background radiation
Cosmological parameters
Early Universe
Large-scale structure of Universe
Cosmology: theory
Cosmology: observations
Acknowledgements. The development of Planck has been supported by:
ESA; CNES and CNRS/INSU-IN2P3-INP (France); ASI, CNR, and INAF
(Italy); NASA and DoE (USA); STFC and UKSA (UK); CSIC, MICINN,
JA and RES (Spain); Tekes, AoF and CSC (Finland); DLR and MPG
(Germany); CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland);
RCN (Norway); SFI (Ireland); FCT/MCTES (Portugal); and PRACE (EU).
A description of the Planck Collaboration and a list of its members,
including the technical or scientific activities in which they have been
involved, can be found at http://www.sciops.esa.int/index.php?
project=planck&page=Planck_Collaboration. We also wish to acknowledge the use of the COSMOS supercomputer, part of the DiRAC HPC Facility
funded by STFC and the UK Large Facilities Capital Fund, use of the
Andromeda cluster of the University of Geneva, and resources of the National
Energy Research Scientific Computing Center.
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 f10 at multipole ℓ = 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/c2 < 1.5 × 10-7 and f10 < 0.015 at 95% confidence that can be improved to Gμ/c2 < 1.3 × 10-7 and f10 < 0.010 on inclusion of high-ℓ CMB data. For the Abelian-Higgs field theory model we find, GμAH/c2< 3.2 × 10-7 and f10 < 0.028. The marginalised likelihoods for f10 and in the f10–Ωbh2 plane are also presented. We have additionally obtained comparable constraints on f10 for models with semilocal strings and global textures. In terms of the effective defect energy scale these are somewhat weaker at Gμ/c2 < 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 ΔGμ/c2 ≈ 4 × 10-7. We have obtained upper limits on the string tension at 95% confidence of Gμ/c2 < 9.0 × 10-7 with modal bispectrum estimation and Gμ/c2 < 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.
2020-07-01T09:58:21Z
2020-07-01T09:58:21Z
2014-10-29
info:eu-repo/semantics/article
Ade, P. A., Aghanim, N., Armitage-Caplan, C., Arnaud, M., Ashdown, M., Atrio-Barandela, F., ... & Bartlett, J. G. (2014). Planck 2013 results. XXV. Searches for cosmic strings and other topological defects. Astronomy & Astrophysics, 571, A25. [https://doi.org/10.1051/0004-6361/201321621]
http://hdl.handle.net/10481/62805
10.1051/0004-6361/201321621
eng
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
info:eu-repo/semantics/openAccess
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