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Hubble trouble or Hubble bubble?

The recent analysis of low-redshift supernovae (SN) has increased the apparent tension between the value of $H_0$ estimated from low and high redshift observations such as the cosmic microwave background (CMB) radiation. At the same time other observations have provided evidence of the existence of...

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Autor principal: Romano, Antonio Enea
Lenguaje:eng
Publicado: 2016
Materias:
Acceso en línea:https://dx.doi.org/10.1142/S021827181850102X
http://cds.cern.ch/record/2215645
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author Romano, Antonio Enea
author_facet Romano, Antonio Enea
author_sort Romano, Antonio Enea
collection CERN
description The recent analysis of low-redshift supernovae (SN) has increased the apparent tension between the value of $H_0$ estimated from low and high redshift observations such as the cosmic microwave background (CMB) radiation. At the same time other observations have provided evidence of the existence of local radial inhomogeneities extending in different directions up to a redshift of about $0.07$. About $40\%$ of the Cepheids used for SN calibration are directly affected because are located along the directions of these inhomogeneities. We derive a new simple formula relating directly the luminosity distance to the monopole of the density contrast, which does not involve any metric perturbation. We then use it to develop a new inversion method to reconstruct the monopole of the density field from the deviations of the redshift uncorrected observed luminosity distance respect to the $\Lambda CDM$ prediction based on cosmological parameters obtained from large scale observations. The inversion method confirms the existence of inhomogeneities whose effects were not previously taken into account because the $2M++$ density field maps used to obtain the peculiar velocity for redshift correction were for $z\leq 0.06$, which is not a sufficiently large scale to detect the presence of inhomogeneities extending up to $z=0.07$. The inhomogeneity does not affect the high redshift luminosity distance because the volume averaged density contrast tends to zero asymptotically, making the value of $H_0^{CMB}$ obtained from CMB observations insensitive to any local structure. The inversion method can provide a unique tool to reconstruct the density field at high redshift where only SN data is available, and in particular to normalize correctly the density field respect to the average large scale density of the Universe.
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spelling cern-22156452021-05-03T20:16:11Zdoi:10.1142/S021827181850102Xhttp://cds.cern.ch/record/2215645engRomano, Antonio EneaHubble trouble or Hubble bubble?astro-ph.COAstrophysics and AstronomyThe recent analysis of low-redshift supernovae (SN) has increased the apparent tension between the value of $H_0$ estimated from low and high redshift observations such as the cosmic microwave background (CMB) radiation. At the same time other observations have provided evidence of the existence of local radial inhomogeneities extending in different directions up to a redshift of about $0.07$. About $40\%$ of the Cepheids used for SN calibration are directly affected because are located along the directions of these inhomogeneities. We derive a new simple formula relating directly the luminosity distance to the monopole of the density contrast, which does not involve any metric perturbation. We then use it to develop a new inversion method to reconstruct the monopole of the density field from the deviations of the redshift uncorrected observed luminosity distance respect to the $\Lambda CDM$ prediction based on cosmological parameters obtained from large scale observations. The inversion method confirms the existence of inhomogeneities whose effects were not previously taken into account because the $2M++$ density field maps used to obtain the peculiar velocity for redshift correction were for $z\leq 0.06$, which is not a sufficiently large scale to detect the presence of inhomogeneities extending up to $z=0.07$. The inhomogeneity does not affect the high redshift luminosity distance because the volume averaged density contrast tends to zero asymptotically, making the value of $H_0^{CMB}$ obtained from CMB observations insensitive to any local structure. The inversion method can provide a unique tool to reconstruct the density field at high redshift where only SN data is available, and in particular to normalize correctly the density field respect to the average large scale density of the Universe.The recent analysis of low-redshift supernovae (SN) has increased the apparent tension between the value of H0 estimated from low and high redshift observations such as the cosmic microwave background (CMB) radiation. At the same time other observations have provided evidence of the existence of local radial inhomogeneities extending in different directions up to a redshift of about 0.07. About 40% of the Cepheids used for SN calibration are directly affected because they are located along the directions of these inhomogeneities. We compute with different methods the effects of these inhomogeneities on the low-redshift luminosity and angular diameter distance using an exact solution of the Einstein’s equations, linear perturbation theory and a low-redshift expansion. We confirm that at low redshift the dominant effect is the nonrelativistic Doppler redshift correction, which is proportional to the volume averaged density contrast and to the comoving distance from the center. We derive a new simple formula relating directly the luminosity distance to the monopole of the density contrast, which does not involve any metric perturbation. We then use it to develop a new inversion method to reconstruct the monopole of the density field from the deviations of the redshift uncorrected observed luminosity distance respect to the ΛCDM prediction based on cosmological parameters obtained from large scale observations. The inversion method confirms the existence of inhomogeneities whose effects were not previously taken into account because the 2M++ [G. Lavaux and M. J. Hudson, Mon. Not. R. Astron. Soc. 416 (2011) 2840] density field maps used to obtain the peculiar velocity [J. Carrick et al., Mon. Not. R. Astron. Soc. 450 (2015) 317] for redshift correction were for z ≤ 0.06, which is not a sufficiently large scale to detect the presence of inhomogeneities extending up to z = 0.07. The inhomogeneity does not affect the high redshift luminosity distance because the volume averaged density contrast tends to zero asymptotically, making the value of H0CMB obtained from CMB observations insensitive to any local structure. The inversion method can provide a unique tool to reconstruct the density field at high redshift where only SN data is available, and in particular to normalize correctly the density field respect to the average large scale density of the Universe.arXiv:1609.04081oai:cds.cern.ch:22156452016-09-13
spellingShingle astro-ph.CO
Astrophysics and Astronomy
Romano, Antonio Enea
Hubble trouble or Hubble bubble?
title Hubble trouble or Hubble bubble?
title_full Hubble trouble or Hubble bubble?
title_fullStr Hubble trouble or Hubble bubble?
title_full_unstemmed Hubble trouble or Hubble bubble?
title_short Hubble trouble or Hubble bubble?
title_sort hubble trouble or hubble bubble?
topic astro-ph.CO
Astrophysics and Astronomy
url https://dx.doi.org/10.1142/S021827181850102X
http://cds.cern.ch/record/2215645
work_keys_str_mv AT romanoantonioenea hubbletroubleorhubblebubble