Suppressing CMB low multipoles with ISW effect

Abstract

Recent results of Planck data reveal that the power in the low multipoles of the CMB angular power spectrum, approximately up to $l=30$, is significantly lower than the theoretically predicted in the best fit $\Lambda$CDM model. In this paper we investigate the possibility of invoking the Integrated Sachs-Wolfe (ISW) effect to explain this power deficit at low multipoles. The ISW effect that originates from the late time expansion history of the universe is rich in possibilities given the limited understanding of the origin of dark energy (DE). It is a common understanding that the ISW effect adds to the power at the low multipoles of the CMB angular power spectrum. In this paper we carry out an analytic study to show that there are some expansion histories in which the ISW effect, instead of adding power, provides negative contribution to the power at low multipoles. Guided by the analytic study, we present examples of the features required in the late time expansion history of the universe that could explain the power deficiency through the ISW effect. We also show that an ISW origin of power deficiency is consistent, at present, with other cosmological observations that probe the expansion history such as distance modulus, matter power spectrum and the evolution of cluster number count. We also show that the ISW effect may be distinguished from power deficit originating from features in the PPS using the measurements of the CMB polarization spectrum at low multipoles expected from Planck. We conclude that the power at low multipoles of the CMB anisotropy could well be closely linked to Dark Energy puzzle in cosmology and this observation could be actually pointing to richer phenomenology of DE beyond the cosmological constant $\Lambda$. (abbreviated)

20 pages, 7 figures

References in corpus (5)

• Cosmic Microwave Background Quadrupole and Ellipsoidal Universe
• Ellipsoidal Universe Can Solve The CMB Quadrupole Problem
• ISW effect in Unified Dark Matter Scalar Field Cosmologies: an analytical approach
• Evidence for horizon-scale power from CMB polarization
• An analytic approach to the late ISW effect in a Lambda dominated universe

Cited by in corpus (17)

• Brans-Dicke cosmology with a $\Lambda$- term: a possible solution to $\Lambda$CDM tensions
• Quantum Gravity in the Sky: Interplay between fundamental theory and observations
• Primordial tensor modes of the early Universe
• The size of our causal Universe
• Joint Planck and WMAP Assessment of Low CMB Multipoles
• Tensor to scalar ratio and large scale power suppression from pre-slow roll initial conditions
• Revisiting a pre-inflationary radiation era and its effect on the CMB power spectrum
• Hint of a truncated primordial spectrum from the CMB large-scale anomalies
• A measurement of the scale of homogeneity in the Early Universe
• Symmetry Reduced Loop Quantum Gravity: A Bird's Eye View
• Explaining low l anomalies in the CMB power spectrum with resonant superstring excitations during inflation
• SCoPE: An efficient method of Cosmological Parameter Estimation
• Possible Evidence for Planck-Scale Resonant Particle Production during Inflation from the CMB Power Spectrum
• Cosmic Microwave Background Anisotropy numerical solution (CMBAns) I: An introduction to $C_l$ calculation
• Anisotropic power spectrum and the observed low-l power in PLANCK CMB data
• Addressing the DESI DR2 Phantom-Crossing Anomaly and Enhanced $H_0$ Tension with Reconstructed Scalar-Tensor Gravity
• Cosmic tango between the very small and the very large: Addressing CMB anomalies through Loop Quantum Cosmology