The peculiar velocity field: constraining the tilt of the Universe

Abstract

A large bulk flow, which is in tension with the Lambda Cold Dark Matter ($\Lambda$CDM) cosmological model, has been observed. In this paper, we provide a physically plausible explanation of this bulk flow, based on the assumption that some fraction of the observed dipole in the cosmic microwave background is due to an intrinsic fluctuation, so that the subtraction of the observed dipole leads to a mismatch between the cosmic microwave background (CMB) defined rest frame and the matter rest frame. We investigate a model that takes into account the relative velocity (hereafter the tilted velocity) between the two frames, and develop a Bayesian statistic to explore the likelihood of this tilted velocity. By studying various independent peculiar velocity catalogs, we find that: (1) the magnitude of the tilted velocity $u$ is around 400 km/s, and its direction is close to what is found from previous bulk flow analyses; for most catalogs analysed, u=0 is excluded at about the $2.5\sigma$ level;(2) constraints on the magnitude of the tilted velocity can result in constraints on the duration of inflation, due to the fact that inflation can neither be too long (no dipole effect) nor too short (very large dipole effect); (3) Under the assumption of a super-horizon isocurvature fluctuation, the constraints on the tilted velocity require that inflation lasts at least 6 e-folds longer (at the 95% confidence interval) than that required to solve the horizon problem. This opens a new window for testing inflation and models of the early Universe from observations of large scale structure.

arXiv comment7 pages, 7 figures, match the published version in Phys.Rev.D

References in corpus (26)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Cosmological Results from High-z Supernovae
• The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances
• Consistently Large Cosmic Flows on Scales of 100 Mpc/h: a Challenge for the Standard LCDM Cosmology
• A measurement of large-scale peculiar velocities of clusters of galaxies: results and cosmological implications
• A new measurement of the bulk flow of X-ray luminous clusters of galaxies
• Cosmic Flows on 100 Mpc/h Scales: Standardized Minimum Variance Bulk Flow, Shear and Octupole Moments
• Reconstructed Density and Velocity Fields from the 2MASS Redshift Survey
• The Atacama Cosmology Telescope: A Measurement of the Cosmic Microwave Background Power Spectrum at 148 and 218 GHz from the 2008 Southern Survey
• Cosmic flow from 2MASS redshift survey: The origin of CMB dipole and implications for LCDM cosmology
• Streaming motions of galaxy clusters within 12000 km/s - V. The peculiar velocity field
• Angular Power Spectra of the Millimeter Wavelength Background Light from Dusty Star-forming Galaxies with the South Pole Telescope
• Superhorizon Perturbations and the Cosmic Microwave Background
• Redshift-Distance Survey of Early-Type Galaxies: Spectroscopic Data
• The peculiar motions of early-type galaxies in two distant regions - VII. Peculiar velocities and bulk motions
• Seeking the Local Convergence Depth. V. Tully-Fisher Peculiar Velocities for 52 Abell Clusters
• Redshift-distance Survey of Early-type Galaxies: the ENEARc Cluster Sample
• Redshift-Distance Survey of Early-type Galaxies. I. Sample Selection, Properties and Completeness
• The Motions of Clusters of Galaxies and the Dipoles of the Peculiar Velocity Field
• The LCO/Palomar 10,000 km/sec Cluster Survey. II. Constraints on Large-Scale Streaming
• Gauging the cosmic microwave background
• Dipole Anisotropy from an Entropy Gradient
• Cosmic Microwave Background Dipole induced by double inflation
• A Test for Large-Scale Systematic Errors in Maps of Galactic Reddening
• Scale of Homogeneity of the Universe from WMAP
• Determining the motion of the solar system relative to the cosmic microwave background using type Ia supernovae

Cited by in corpus (58)

• Dark energy two decades after: Observables, probes, consistency tests
• Cosmic flows in the nearby universe from Type Ia Supernovae
• Testing $\Lambda$CDM at the lowest redshifts with SN Ia and galaxy velocities
• The 6dF Galaxy Velocity Survey: Cosmological constraints from the velocity power spectrum
• Analyzing the Large-Scale Bulk Flow using CosmicFlows4: Increasing Tension with the Standard Cosmological Model
• The 6dF Galaxy Survey: Bulk Flows on $50-70h^{-1}$ Mpc scales
• 2MTF VI. Measuring the velocity power spectrum
• CMB Imprints of a Pre-Inflationary Climbing Phase
• Probing the anisotropic expansion from supernovae and GRBs in a model-independent way
• The Sloan Digital Sky Survey Peculiar Velocity Catalogue
• Cosmic bulk flows on 50 {h}^{-1}Mpc scales: A Bayesian hyper-parameter method and multishells likelihood analysis
• Improving constraints on the growth rate of structure by modelling the density-velocity cross-correlation in the 6dF Galaxy Survey
• Searching for Modified Gravity: Scale and Redshift Dependent Constraints from Galaxy Peculiar Velocities
• Dipolar modulation in number counts of WISE-2MASS sources
• Probing bulk flow with nearby SNe Ia data
• Evaluating bulk flow estimators for CosmicFlows-4 measurements
• An estimation of local bulk flow with the maximum-likelihood method
• No evidence for bulk velocity from type Ia supernovae
• Power Spectrum Estimation from Peculiar Velocity Catalogues
• Large-scale Cosmic Flows from Cosmicflows-2 Catalog
• Isotropy of low redshift type Ia Supernovae: A Bayesian analysis
• The multipole expansion of the local expansion rate
• Detected fluctuations in SDSS LRG magnitudes: Bulk flow signature or systematic?
• Complementarity of Peculiar Velocity Surveys and Redshift Space Distortions for Testing Gravity
• Studying the Peculiar Velocity Bulk Flow in a Sparse Survey of Type-Ia SNe
• Bulk flow and shear in the local Universe: 2MTF and COSMICFLOWS-3
• Using peculiar velocity surveys to constrain the growth rate of structure with the wide-angle effect
• Constraining the local variance of $H_0$ from directional analyses
• Wide angle effects for peculiar velocities
• Beyond the Boost: Measuring the intrinsic dipole of the CMB using the spectral distortions of the monopole and quadrupole
• Growth-rate measurement with type-Ia supernovae using ZTF survey simulations
• Finsler geometric perspective on the bulk flow in the universe
• Testing the minimum variance method for estimating large-scale velocity moments
• Double-Kasner Spacetime: Peculiar Velocities and Cosmic Jets
• Constraining cosmology with pairwise velocity estimator
• Constraints on Pre-inflation Fluctuations in a Nearly Flat Open ΛCDM Cosmology
• Cosmic Flow Measurement and Mock Sampling Algorithm of Cosmicflows-4 Tully-Fisher Catalogue
• Detectability of Cosmic Dark Flow in the Type Ia Supernova Redshift-Distance Relation
• Cosmology with Peculiar Velocities: Observational Effects
• Peculiar Transverse Velocities of Galaxies from Quasar Microlensing. Tentative Estimate of the Peculiar Velocity Dispersion at $z\sim 0.5$
• Independent constraints on local non-Gaussianity from the peculiar velocity and density fields
• Probing the rest-frame of the Universe with near-IR cosmic infrared background
• Planck intermediate results. LIII. Detection of velocity dispersion from the kinetic Sunyaev-Zeldovich effect
• Forecast for growth-rate measurement using peculiar velocities from LSST supernovae
• Friction forces in cosmological models
• Yet another sample of RFGC galaxies
• Is the local Hubble flow consistent with concordance cosmology?
• Constraining the optical depth of galaxies and velocity bias with cross-correlation between kinetic Sunyaev-Zeldovich effect and peculiar velocity field
• Velocities hasten to tell us about the Universe
• Statistical effects of the observer's peculiar velocity on source number counts
• A CMB Gibbs sampler for localized secondary anisotropies
• A probabilistic framework for cosmological inference of peculiar velocities
• Constraints on the birth of the universe and origin of cosmic dark flow
• Anchors no more: Using peculiar velocities to constrain $H_0$ and the primordial Universe without calibrators
• Squared-field cross-correlation between kinetic Sunyaev-Zel'dovich effect and 21-cm intensity mapping
• Cosmic Dipoles from Large-Scale Structure Surveys
• Galaxy number-count dipole and superhorizon fluctuations
• First constraints on the intrinsic CMB dipole and our velocity with Doppler and aberration