The KBC void and Hubble tension contradict $Λ$CDM on a Gpc scale $-$ Milgromian dynamics as a possible solution

Haslbauer, Moritz; Banik, Indranil; Kroupa, Pavel

doi:10.48550/arxiv.2009.11292

“…Our analysis is confirming the existence of a local underdensity surrounding us in different directions [1,16,17]. The probability of formation of such an inhomogeneity is low in the CDM framework, but modified gravity [18] could alleviate this problem.…”

Section: Introductionsupporting

confidence: 77%

$$H_0$$ tension or M overestimation?

Valle¹,

Enea²,

Carvajal³

2022

Eur. Phys. J. C

0

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There is a strong discrepancy between the value of the Hubble parameter $$H_0^P$$ H 0 P obtained from large scale observations such as the Planck mission, and the small scale value $$H_0^R$$ H 0 R , obtained from low redshift supernovae (SNe). The value of the absolute magnitude $$M^{Hom}$$ M Hom used as prior in analyzing observational data is obtained from low-redshift SNe, assuming a homogeneous Universe, but the distance of the anchors used to calibrate the SNe to obtain M would be affected by a local inhomogeneity, making it inconsistent to test the Copernican principle using $$M^{Hom}$$ M Hom , since M estimation itself is affected by local inhomogeneities. We perform an analysis of the luminosity distance of low redshift SNe, using different values of M, $$\{M^P,M^R\}$$ { M P , M R } , corresponding to different values of $$H_0$$ H 0 , $$\{H_0^P,H_0^R\}$$ { H 0 P , H 0 R } , obtained from the model independent consistency relation between $$H_0$$ H 0 and M which can be derived from the definition of the distance modulus. We find that the value of M can strongly affect the evidence of a local inhomogeneity. We analyze data from the Pantheon catalog, finding no significant statistical evidence of a local inhomogeneity using the parameters $$\{M^R,H_0^R\}$$ { M R , H 0 R } , confirming previous studies, while with $$\{M^P,H_0^P\}$$ { M P , H 0 P } we find evidence of a small local void, which causes an overestimation of $$M^R$$ M R with respect to $$M^P$$ M P . An inhomogeneous model with the parameters $$\{M^P,H_0^P\}$$ { M P , H 0 P } fits the data better than a homogeneous model with $$\{M^R,H_0^R\}$$ { M R , H 0 R } , resolving the apparent $$H_0$$ H 0 tension. Using $$\{M^P,H_0^P\}$$ { M P , H 0 P } , we obtain evidence of a local inhomogeneity with a density contrast $$-0.140 \pm 0.042 $$ - 0.140 ± 0.042 , extending up to a redshift of $$z_v =0.056 \pm 0.0002$$ z v = 0.056 ± 0.0002 , in good agreement with recent results of galaxy catalogs analysis (Wong et al. in The local hole: a galaxy under-density covering 90 mpc, 2021).

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“…This is interesting since all lenses should be subject to the same assumptions, so if there is a systematic, then all lenses are affected. Nevertheless, the descending trend in H 0 can be expected to be robust [22] and it has prompted various explanations [20,112]. However, it is possible that it is not a trend with lens redshift, but due to the line of sight (LOS) anisotropy as we outline here.…”

Section: Discussionmentioning

confidence: 89%

Does Hubble Tension Signal a Breakdown in FLRW Cosmology?

Krishnan,

Mohayaee,

Colgáin

et al. 2021

Preprint

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The tension between early and late Universe probes of the Hubble constant has motivated various new FLRW cosmologies. Here, we reanalyse the Hubble tension with a recent age of the Universe constraint. This allows us to restrict attention to matter and a dark energy sector that we treat without assuming a specific model. Assuming analyticity of the Hubble parameter H(z), and a generic low redshift modification to flat ΛCDM, we find that low redshift data (z 2.5) and well-motivated priors only permit a dark energy sector close to the cosmological constant Λ. This restriction rules out late Universe modifications within FLRW. We show that early Universe physics that alters the sound horizon can yield an upper limit of H0 ∼ 71 ± 1 km/s/Mpc. Since various local determinations may be converging to H0 ∼ 73 km/s/Mpc, a breakdown of the FLRW framework is a plausible resolution. We outline how future data, in particular strongly lensed quasar data, could also provide further confirmations of such a resolution."How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" -Sherlock Holmes

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“…Moreover, the Hubble tension is slightly alleviated but the jury is still out on the high value of the R19 measurement. The claim that its origin is a huge local void(Haslbauer, Banik, & Kroupa, 2020;Kim, Kang, Lee, & Jang, 1920) might be an alternative explanation.…”

mentioning

confidence: 99%

Rigorous derivation of dark energy and inflation as geometry effects in Covariant Canonical Gauge Gravity

Vasak,

Kirsch,

Struckmeier

2021

Preprint

0

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The cosmological implications of the Covariant Canonical Gauge Theory of Gravity (CCGG) are investigated. CCGG is a Palatini theory derived from first principles using the canonical transformation formalism in the covariant Hamiltonian formulation. The Einstein-Hilbert theory is thereby extended by a quadratic Riemann-Cartan term in the Lagrangian. Moreover, the requirement of covariant conservation of the stress-energy tensor leads to necessary presence of torsion. In the Friedman universe that promotes the cosmological constant to a time-dependent function, and gives rise to a geometrical correction with the EOS of dark radiation. The resulting cosmology, compatible with the ΛCDM parameter set, encompass)es bounce and bang scenarios with graceful exits into the late dark energy era. Testing those scenarios against low-observations shows that CCGG is a viable theory.

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The KBC void and Hubble tension contradict $Λ$CDM on a Gpc scale $-$ Milgromian dynamics as a possible solution

Cited by 3 publications

References 194 publications

$$H_0$$ tension or M overestimation?

Does Hubble Tension Signal a Breakdown in FLRW Cosmology?

Rigorous derivation of dark energy and inflation as geometry effects in Covariant Canonical Gauge Gravity

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