CMB dipoles and other low-order multipoles in the quasispherical Szekeres model

Abstract

Several authors have previously shown that Gpc-scale void based on the spherically symmetric LTB model can provide a good fit to certain cosmological data, including the SNIa data, but it is only consistent with the observed CMB dipole if we are located very close to the center, in violation of the Copernican principle. In this work we investigate the more general quasispherical Szekeres model, which does not include spherical symmetry, in order to determine whether this option may be less constricting. We find that the observer is still constrained to a small region, but it is not as geometrically ``special'' as the center of an LTB void. Furthermore, whereas the quadrupole and octupole near the center of an LTB void are necessarily small, certain Szekeres models can include a significant quadrupole while still being consistent with the observed dipole, hinting that Szekeres models may be able give an explanation for the observed quadrupole/octupole anomalies.

14 pages, 8 figures, originally published in Phys. Rev. D in 2013

References in corpus (15)

• A general test of the Copernican Principle
• Cosmic clocks, cosmic variance and cosmic averages
• Confronting Lemaitre-Tolman-Bondi models with Observational Cosmology
• A Test of the Copernican Principle
• CMB anisotropies seen by an off-center observer in a spherically symmetric inhomogeneous universe
• Looking the void in the eyes - the kSZ effect in LTB models
• Testing the Void against Cosmological data: fitting CMB, BAO, SN and H0
• Scalar Perturbations on Lemaitre-Tolman-Bondi Spacetimes
• Linear kinetic Sunyaev-Zel'dovich effect and void models for acceleration
• Redshift Drift in LTB Void Universes
• Dark Energy or Apparent Acceleration Due to a Relativistic Cosmological Model More Complex than FLRW?
• Cosmic spherical void via coarse-graining and averaging non-spherical structures
• Redshift propagation equations in the ${\beta }^{\prime }\ne 0$ Szekeres models
• LTB universes as alternatives to dark energy: does positive averaged acceleration imply positive cosmic acceleration?
• Spatial and temporal tuning in void models for acceleration

Cited by in corpus (5)

• Planck CMB Anomalies: Astrophysical and Cosmological Secondary Effects and the Curse of Masking
• Effect of inhomogeneities on high precision measurements of cosmological distances
• On general-relativistic Lagrangian perturbation theory and its non-perturbative generalization
• Beyond relativistic Lagrangian perturbation theory. I. An exact-solution controlled model for structure formation
• Rotation, Embedding and Topology for the Szekeres Geometry