Leverage on small-scale primordial non-Gaussianity through cross-correlations between CMB $E$-mode and $\mu$-distortion anisotropies

Abstract

Multi-field inflation models and non-Bunch-Davies vacuum initial conditions both predict sizeable non-Gaussian primordial perturbations and anisotropic $\mu$-type spectral distortions of the cosmic microwave background (CMB) blackbody. While CMB anisotropies allow us to probe non-Gaussianity at wavenumbers $k\simeq 0.05\mathrm{Mp}{\mathrm{c}}^{-1}$, $\mu$-distortion anisotropies are related to non-Gaussianity of primordial perturbation modes with much larger wavenumbers, $k\simeq 740\mathrm{Mp}{\mathrm{c}}^{-1}$. Through cross-correlations between CMB and $\mu$-distortion anisotropies, one can therefore shed light on the aforementioned inflation models. We investigate the ability of a future CMB satellite imager like LiteBIRD to measure $\mu T$ and $\mu E$ cross-power spectra between anisotropic $\mu$-distortions and CMB temperature and $E$-mode polarization anisotropies in the presence of foregrounds, and derive LiteBIRD forecasts on $f_{\mathrm{NL}}^{\mu }(k\simeq 740\mathrm{Mp}{\mathrm{c}}^{-1})$. We show that $\mu E$ cross-correlations with CMB polarization provide more constraining power on $f_{\mathrm{NL}}^{\mu }$ than $\mu T$ cross-correlations in the presence of foregrounds, and the joint combination of $\mu T$ and $\mu E$ observables adds further leverage to the detection of small-scale primordial non-Gaussianity. We find that LiteBIRD would detect $f_{\mathrm{NL}}^{\mu }=4500$ at $5\sigma$ significance after foreground removal, and achieve a minimum error of $\sigma (f_{\mathrm{NL}}^{\mu }=0)\simeq 800$ at 68\% CL by combining CMB temperature and polarization. Due to the huge dynamic range of wavenumbers between CMB and $\mu$-distortion anisotropies, such large $f_{\mathrm{NL}}^{\mu }$ values would still be consistent with current CMB constraints in the case of very mild scale-dependence of primordial non-Gaussianity. Anisotropic spectral distortions thus provide a new path, complementary to CMB $B$-modes, to probe inflation with LiteBIRD.

arXiv comment17 pages, 11 figures, updated to match version accepted by MNRAS

References in corpus (56)

• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Interstellar Dust Grains
• The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
• Toward a halo mass function for precision cosmology: the limits of universality
• Acoustic Signatures in the Primary Microwave Background Bispectrum
• The universal galaxy cluster pressure profile from a representative sample of nearby systems (REXCESS) and the Y_SZ-M_500 relation
• MASTER of the CMB Anisotropy Power Spectrum: A Fast Method for Statistical Analysis of Large and Complex CMB Data Sets
• The Primordial Inflation Explorer (PIXIE): A Nulling Polarimeter for Cosmic Microwave Background Observations
• The Three--Point Correlation Function of the Cosmic Microwave Background in Inflationary Models
• Determination of Inflationary Observables by Cosmic Microwave Background Anisotropy Experiments
• Electric Dipole Radiation from Spinning Dust Grains
• Planck 2018 results. IV. Diffuse component separation
• The evolution of CMB spectral distortions in the early Universe
• Relativistic Corrections to the Sunyaev-Zel'dovich Effect for Clusters of Galaxies
• Large-scale structure, the cosmic microwave background, and primordial non-gaussianity
• Planck 2013 results. XXX. Cosmic infrared background measurements and implications for star formation
• A full sky, low foreground, high resolution CMB map from WMAP
• The pre-launch Planck Sky Model: a model of sky emission at submillimetre to centimetre wavelengths
• CMB at 2x2 order: the dissipation of primordial acoustic waves and the observable part of the associated energy release
• Running Non-Gaussianities in DBI Inflation
• Astrophysics with the Spatially and Spectrally Resolved Sunyaev-Zeldovich Effects: A Millimetre/Submillimetre Probe of the Warm and Hot Universe
• Separation of anomalous and synchrotron emissions using WMAP polarization data
• CMB and SZ effect separation with Constrained Internal Linear Combinations
• Planck 2018 results. XII. Galactic astrophysics using polarized dust emission
• Power Spectrum Constraints from Spectral Distortions in the Cosmic Microwave Background
• A determination of the Spectra of Galactic components observed by WMAP
• LiteBIRD: JAXA's new strategic L-class mission for all-sky surveys of cosmic microwave background polarization
• Scale-dependent non-Gaussianity probes inflationary physics
• Reionization and cosmic microwave background distortions: a complete treatment of second order Compton scattering
• A fast and accurate method for computing the Sunyaev-Zeldovich signal of hot galaxy clusters
• Which spectral distortions does $\Lambda$CDM actually predict?
• A New Window on Primordial non-Gaussianity
• Scale-dependent bias of galaxies and mu-type distortion of the cosmic microwave background spectrum from single-field inflation with a modified initial state
• A needlet ILC analysis of WMAP 7-year data: estimation of CMB temperature map and power spectrum
• Taking the Universe's Temperature with Spectral Distortions of the Cosmic Microwave Background
• A generalized local ansatz and its effect on halo bias
• The synergy between CMB spectral distortions and anisotropies
• Prospects for Measuring Cosmic Microwave Background Spectral Distortions in the Presence of Foregrounds
• Spectral distortion constraints on photon injection from low-mass decaying particles
• Peeling off foregrounds with the constrained moment ILC method to unveil primordial CMB $B$-modes
• Unavoidable CMB spectral features and blackbody photosphere of our Universe
• Probing the scale dependence of non-Gaussianity with spectral distortions of the cosmic microwave background
• Can we neglect relativistic temperature corrections in the Planck thermal SZ analysis?
• Quantum Suppression of Alignment in Ultrasmall Grains: Microwave Emission from Spinning Dust will be Negligibly Polarized
• The y-sky: diffuse spectral distortions of the cosmic microwave background
• Evolution of CMB spectral distortion anisotropies and tests of primordial non-Gaussianity
• Mapping the relativistic electron gas temperature across the sky
• Extracting foreground-obscured $\mu$-distortion anisotropies to constrain primordial non-Gaussianity
• Spectral distortion anisotropies from single-field inflation
• Primordial non-Gaussianity with $\mu$-type and $y$-type spectral distortions: exploiting Cosmic Microwave Background polarization and dealing with secondary sources
• Sensitivity forecasts for the cosmological recombination radiation in the presence of foregrounds
• Correlating CMB Spectral Distortions with Temperature: what do we learn on Inflation?
• Cosmological constraints from $\mu E$ cross-correlations
• Measuring primordial anisotropic correlators with CMB spectral distortions
• CMB $\mu T$ cross-correlations as a probe of PBH scenarios
• FSD: Frequency Space Differential measurement of CMB spectral distortions

Cited by in corpus (2)

• CMB spectral distortions revisited: a new take on $\mu$ distortions and primordial non-Gaussianities from FIRAS data
• Non-Gaussianity constraints from Planck spectral distortion cross-correlations