Can Topological Defects Mimic the BICEP2 B-Mode Signal?

Joanes Lizarraga*, Jon Urrestilla, David Daverio, Mark Hindmarsh, Martin Kunz, Andrew R. Liddle

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


We show that the B-mode polarization signal detected at low multipoles by BICEP2 cannot be entirely due to topological defects. This would be incompatible with the high-multipole B-mode polarization data and also with existing temperature anisotropy data. Adding cosmic strings to a model with tensors, we find that B modes on their own provide a comparable limit on the defects to that already coming from Planck satellite temperature data. We note that strings at this limit give a modest improvement to the best fit of the B-mode data, at a somewhat lower tensor-to-scalar ratio of r similar or equal to 0.15.

Original languageEnglish
Article number171301
Number of pages3
JournalPhysical Review Letters
Issue number17
Publication statusPublished - 29 Apr 2014



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