Can Self-Ordering Scalar Fields explain the BICEP2 B-mode signal?

Abstract

We show that self-ordering scalar fields (SOSF), i.e. non-topological cosmic defects arising after a global phase transition, cannot explain the B-mode signal recently announced by BICEP2. We compute the full $C_{\ell }^B$ angular power spectrum of B-modes due to the vector and tensor perturbations of SOSF, modeled in the large-N limit of a spontaneous broken global O(N) symmetry. We conclude that the low-$\ell$ multipoles detected by BICEP2 cannot be due mainly to SOSF, since they have the wrong spectrum at low multipoles. As a byproduct we derive the first cosmological constraints on this model, showing that the BICEP2 B-mode polarization data admits at most a 2-3% contribution from SOSF in the temperature anisotropies, similar to (but somewhat tighter than) the recently studied case of cosmic strings.

14 pages, 5 figures

References in corpus (43)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Planck 2013 results. I. Overview of products and scientific results
• BICEP2 I: Detection Of B-mode Polarization at Degree Angular Scales
• Cosmic strings
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Power Spectra and WMAP-Derived Parameters
• Signature of Gravity Waves in Polarization of the Microwave Background
• A Probe of Primordial Gravity Waves and Vorticity
• Planck 2013 results. XV. CMB power spectra and likelihood
• The Atacama Cosmology Telescope: Cosmological Parameters from the 2008 Power Spectra
• The number of cosmic string loops
• Planck 2013 results. XXV. Searches for cosmic strings and other topological defects
• Theory and Numerics of Gravitational Waves from Preheating after Inflation
• Toward an Understanding of Foreground Emission in the BICEP2 Region
• A Gravitational Wave Background from Reheating after Hybrid Inflation
• Gravitational-Wave Stochastic Background from Kinks and Cusps on Cosmic Strings
• A measurement of secondary cosmic microwave background anisotropies with two years of South Pole Telescope observations
• A stochastic background of gravitational waves from hybrid preheating
• Power Spectra in Global Defect Theories of Cosmic Structure Formation
• Cosmic Structure Formation with Topological Defects
• Gravitational Waves from Abelian Gauge Fields and Cosmic Strings at Preheating
• Exact Scale-Invariant Background of Gravitational Waves from Cosmic Defects
• Signals of Inflationary Models with Cosmic Strings
• CMB polarization as a direct test of Inflation
• Cosmic Microwave Background Anisotropies from Scaling Seeds: Global Defect Models
• The Gravitational Wave Spectrum from Cosmological B-L Breaking
• Gravitational waves from self-ordering scalar fields
• A Nearly Scale Invariant Spectrum of Gravitational Radiation from Global Phase Transitions
• Doppler Peaks in the Angular Power Spectrum of the Cosmic Microwave Background: A Fingerprint of Topological Defects
• Did BICEP2 see vector modes? First B-mode constraints on cosmic defects
• Can topological defects mimic the BICEP2 B-mode signal?
• The CMB temperature bispectrum induced by cosmic strings
• Can primordial magnetic fields be the origin of the BICEP2 data?
• Remarks about the Tensor Mode Detection by the BICEP2 Collaboration and the Super-Planckian Excursions of the Inflaton Field
• CMB temperature trispectrum of cosmic strings
• Cosmic String Power Spectrum, Bispectrum and Trispectrum
• Detecting and distinguishing topological defects in future data from the CMBPol satellite
• On the degeneracy between primordial tensor modes and cosmic strings in future CMB data from Planck
• The local B-polarization of the CMB: a very sensitive probe of cosmic defects
• Non-Gaussianity from Self-Ordering Scalar Fields
• Gravitational Waves from Global Second Order Phase Transitions
• Cosmic Microwave Background temperature and polarization anisotropies from the large-N limit of global defects
• A note of clarification: BICEP2 and Planck are not in tension
• Signatures of Topological Defects in the Microwave Sky: An Introduction

Cited by in corpus (13)

• Cosmological Backgrounds of Gravitational Waves
• Bouncing Cosmologies: Progress and Problems
• Primordial Gravitational Waves from Axion-Gauge Fields Dynamics
• Gravitational Waves and Scalar Perturbations from Spectator Fields
• BICEP2 implications for single-field slow-roll inflation revisited
• Constraining topological defects with temperature and polarization anisotropies
• Inflation without quantum gravity
• Gravitational waves as a probe of SUSY scale
• Probing early-universe phase transitions with CMB spectral distortions
• Reheating signature in the gravitational wave spectrum from self-ordering scalar fields
• Primordial magnetic fields from self-ordering scalar fields
• Constraining primordial vector mode from B-mode polarization
• Weak lensing from self-ordering scalar fields