CMB bounds on tensor-scalar-scalar inflationary correlations

Abstract

The nonlinear interaction between one graviton and two scalars is enhanced in specific inflationary models, potentially leading to distinguishable signatures in the bispectrum of the cosmic microwave background (CMB) anisotropies. We develop the tools to examine such bispectrum signatures, and show a first application using WMAP temperature data. We consider several $\ell$-ranges, estimating the $g_{tss}$ amplitude parameter, by means of the so-called separable modal methodology. We do not find any evidence of a tensor-scalar-scalar signal at any scale. Our tightest bound on the size of the tensor-scalar-scalar correlator is derived from our measurement including all the multipoles in the range $2\le \ell \le 500$ and it reads $g_{tss}=-48\pm 28$ ($68\%$CL). This is the first direct observational constraint on the primordial tensor-scalar-scalar correlation, and it will be cross-checked and improved by applying the same pipeline to high-resolution temperature and polarization data from $Planck$ and forthcoming CMB experiments.

arXiv comment14 pages, 5 figures

References in corpus (35)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• Non-Gaussian features of primordial fluctuations in single field inflationary models
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results
• Non-Gaussianity from Inflation: Theory and Observations
• Acoustic Signatures in the Primary Microwave Background Bispectrum
• Second-Order Cosmological Perturbations from Inflation
• Primordial Non-Gaussianities from Inflation Models
• Planck 2015 results. XVII. Constraints on primordial non-Gaussianity
• Planck 2013 Results. XXIV. Constraints on primordial non-Gaussianity
• Non-Gaussianities in Single Field Inflation and their Optimal Limits from the WMAP 5-year Data
• Detection of Gravitational Lensing in the Cosmic Microwave Background
• Measuring primordial non-Gaussianity in the cosmic microwave background
• Hunting for Primordial Non-Gaussianity in the Cosmic Microwave Background
• Optimal limits on f_{NL}^{local} from WMAP 5-year data
• Primordial non-Gaussianity and Bispectrum Measurements in the Cosmic Microwave Background and Large-Scale Structure
• Scale-dependent gravitational waves from a rolling axion
• General CMB and Primordial Bispectrum Estimation I: Mode Expansion, Map-Making and Measures of f_NL
• The CMB Bispectrum
• Parity violation in the CMB bispectrum by a rolling pseudoscalar
• Primordial Non-Gaussianity in the Cosmic Microwave Background
• CMB Bispectrum from Primordial Scalar, Vector and Tensor non-Gaussianities
• Parity violation of primordial magnetic fields in the CMB bispectrum
• Parity Violation of Gravitons in the CMB Bispectrum
• Combining power spectrum and bispectrum measurements to detect oscillatory features
• Optimal limits on primordial magnetic fields from CMB temperature bispectrum of passive modes
• Efficient Wiener filtering without preconditioning
• Polyspectra searches for sharp oscillatory features in cosmic microwave sky data
• On CMB B-Mode Non-Gaussianity
• Observed parity-odd CMB temperature bispectrum
• CMB Scale Dependent Non-Gaussianity from Massive Gravity during Inflation
• General parity-odd CMB bispectrum estimation
• Using inpainting to construct accurate cut-sky CMB estimators
• Polarization bispectrum for measuring primordial magnetic fields

Cited by in corpus (10)

• The Simons Observatory: Science goals and forecasts
• Partially Massless Fields During Inflation
• Probing non-Gaussian Stochastic Gravitational Wave Backgrounds with LISA
• Tensor Non-Gaussianity Search: Current Status and Future Prospects
• Cross-correlations as a Diagnostic Tool for Primordial Gravitational Waves
• CMB B-mode non-Gaussianity: optimal bispectrum estimator and Fisher forecasts
• Probing parity-odd bispectra with anisotropies of GW $V$ modes
• Constraining graviton non-Gaussianity through the CMB bispectra
• Enhanced tensor non-Gaussianities in presence of a source
• Breaking parity: the case of the trispectrum from chiral scalar-tensor theories of gravity