We present a novel approach to disentangle two key contributions to the
largest-scale anisotropy of the galaxy distribution: (i) the intrinsic dipole
due to clustering and anisotropic geometry, and (ii) the kinematic dipole due
to our peculiar velocity. Including the redshift and angular size of galaxies,
in addition to their fluxes and positions allows us to measure both the
direction and amplitude of our velocity independently of the intrinsic dipole
of the source distribution. We find that this new approach applied to future
galaxy surveys (LSST and Euclid) and a SKA radio continuum survey allows to
measure our velocity ($= v/c$) with a relative error in the amplitude
$\sigma(\beta)/1.3 - 4.5\%$ and in direction, $þeta_\beta \sim
0.9^\circ - 3.9^\circ$, well beyond what can be achieved when analysing
only the number count dipole. We also find that galaxy surveys are able to
measure the intrinsic large-scale anisotropy with a relative uncertainty of
$5\%$ (excluding cosmic variance). Our method enables two simultaneous
tests of the Cosmological Principle: comparing the observations of our peculiar
velocity with the CMB dipole, and testing for a significant intrinsic
anisotropy on large scales which indicates effects beyond the standard
cosmological model.
Description
A new test of the Cosmological Principle: measuring our peculiar velocity and the large scale anisotropy independently
%0 Generic
%1 nadolny2021cosmological
%A Nadolny, Tobias
%A Durrer, Ruth
%A Kunz, Martin
%A Padmanabhan, Hamsa
%D 2021
%K tifr
%T A new test of the Cosmological Principle: measuring our peculiar
velocity and the large scale anisotropy independently
%U http://arxiv.org/abs/2106.05284
%X We present a novel approach to disentangle two key contributions to the
largest-scale anisotropy of the galaxy distribution: (i) the intrinsic dipole
due to clustering and anisotropic geometry, and (ii) the kinematic dipole due
to our peculiar velocity. Including the redshift and angular size of galaxies,
in addition to their fluxes and positions allows us to measure both the
direction and amplitude of our velocity independently of the intrinsic dipole
of the source distribution. We find that this new approach applied to future
galaxy surveys (LSST and Euclid) and a SKA radio continuum survey allows to
measure our velocity ($= v/c$) with a relative error in the amplitude
$\sigma(\beta)/1.3 - 4.5\%$ and in direction, $þeta_\beta \sim
0.9^\circ - 3.9^\circ$, well beyond what can be achieved when analysing
only the number count dipole. We also find that galaxy surveys are able to
measure the intrinsic large-scale anisotropy with a relative uncertainty of
$5\%$ (excluding cosmic variance). Our method enables two simultaneous
tests of the Cosmological Principle: comparing the observations of our peculiar
velocity with the CMB dipole, and testing for a significant intrinsic
anisotropy on large scales which indicates effects beyond the standard
cosmological model.
@misc{nadolny2021cosmological,
abstract = {We present a novel approach to disentangle two key contributions to the
largest-scale anisotropy of the galaxy distribution: (i) the intrinsic dipole
due to clustering and anisotropic geometry, and (ii) the kinematic dipole due
to our peculiar velocity. Including the redshift and angular size of galaxies,
in addition to their fluxes and positions allows us to measure both the
direction and amplitude of our velocity independently of the intrinsic dipole
of the source distribution. We find that this new approach applied to future
galaxy surveys (LSST and Euclid) and a SKA radio continuum survey allows to
measure our velocity ($\beta = v/c$) with a relative error in the amplitude
$\sigma(\beta)/\beta \sim 1.3 - 4.5\%$ and in direction, $\theta_{\beta} \sim
0.9^{\circ} - 3.9^{\circ}$, well beyond what can be achieved when analysing
only the number count dipole. We also find that galaxy surveys are able to
measure the intrinsic large-scale anisotropy with a relative uncertainty of
$\lesssim 5\%$ (excluding cosmic variance). Our method enables two simultaneous
tests of the Cosmological Principle: comparing the observations of our peculiar
velocity with the CMB dipole, and testing for a significant intrinsic
anisotropy on large scales which indicates effects beyond the standard
cosmological model.},
added-at = {2021-06-11T08:42:00.000+0200},
author = {Nadolny, Tobias and Durrer, Ruth and Kunz, Martin and Padmanabhan, Hamsa},
biburl = {https://www.bibsonomy.org/bibtex/20288a4d3f45ab79145d4cfe9c19754a6/citekhatri},
description = {A new test of the Cosmological Principle: measuring our peculiar velocity and the large scale anisotropy independently},
interhash = {43891d2f8850b495991259ed87d0aeb4},
intrahash = {0288a4d3f45ab79145d4cfe9c19754a6},
keywords = {tifr},
note = {cite arxiv:2106.05284Comment: 28 pages, 10 figures, 1 table},
timestamp = {2021-06-11T08:42:00.000+0200},
title = {A new test of the Cosmological Principle: measuring our peculiar
velocity and the large scale anisotropy independently},
url = {http://arxiv.org/abs/2106.05284},
year = 2021
}