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A new method, based on the absorption of very high-energy gamma-rays by the cosmic infrared background, is proposed to constrain the value of the Hubble constant. As this value is both fundamental for cosmology and still not very well…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-19 A. Gorecki , A. Barrau , J. Grain , E. Memola

We introduce a novel way of measuring $H_0$ from a combination of independent geometrical datasets, with no need of calibration nor of the choice of a cosmological model. We build on the {\it distance duality relation} which sets the ratio…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-20 Fabrizio Renzi , Alessandra Silvestri

We use 28 Hubble parameter, $H(z)$, measurements at intermediate redshifts $0.07 \leq z \leq 2.3$ to determine the present-day Hubble constant $H_0$ in four cosmological models. We measure $H_0 = 68.3^{ +2.7}_{ -2.6 }, 68.4^{ +2.9 }_{ -3.3…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-26 Yun Chen , Suresh Kumar , Bharat Ratra

In this work, we constrain the Hubble constant parameter, $H_0$, using a combination of the Pantheon sample and galaxy clusters (GC) measurements from minimal cosmological assumptions. Assuming the validity of the cosmic distance duality…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-27 L. R. Colaço , M. S. Ferreira , R. F. L. Holanda , J. E. Gonzalez , Rafael C. Nunes

We present a simultaneous analysis of 18 galaxy lenses with time delay measurements. For each lens we derive mass maps using pixelated simultaneous modeling with shared Hubble constant. We estimate the Hubble constant to be 66_{-4}^{+6}…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-05 Danuta Paraficz , Jens Hjorth

Recent developments in the determination of H0 are reviewed in the context of the 3 following questions: 1) What is required to measure an accurate value of H0? Given the wide range of H0 values quoted in the current literature, is there…

Astrophysics · Physics 2007-05-23 Wendy L. Freedman

The Hubble constant ($H_0$) is one of the most important parameters in the standard $\rm \Lambda CDM$ model. The measurements given by the main two methods show a gap larger than $4\sigma$, which is known as Hubble tension. Fast radio…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-18 D. H. Gao , Q. Wu , J. P. Hu , S. X. Yi , X. Zhou , F. Y. Wang , Z. G. Dai

We establish a cosmological-model-independent method to determine the Hubble constant $H_0$ from the localized fast radio bursts (FRBs) and the Hubble parameter measurements from cosmic chronometers and obtain a first such determination…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-12 Yang Liu , Hongwei Yu , Puxun Wu

For 100 years since galaxies were found to be flying apart from each other, astronomers have been trying to determine how fast. The expansion, characterized by the Hubble constant, H0, is confused locally by peculiar velocities caused by…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-23 R. Brent Tully

Using comoving distance $d_c$ and angular diameter distance $d_A$, we recalculate parameters describing kinematical state of the universe, still combining the kinematical model of universe but not relying on dynamical equations for gravity.…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-27 Hai Huang , Long Huang

Although cosmologists have been trying to determine the value of the Hubble constant for nearly 65 years, they have only succeeded in limiting the range of possibilities: most of the current observational determinations place the Hubble…

Astrophysics · Physics 2009-10-22 J. G. Bartlett , A. Blanchard , J. Silk , M. S. Turner

Bidirectional relativistic proper motions of radio components of nearby extragalactic sources give a strong constraint on the determination of the Hubble constant $H_0$. Under the assumption that the real velocity of radio components of…

Astrophysics · Physics 2009-10-31 Yi-Ping Qin

We present a determination of the Hubble constant from the joint, free-form analysis of 8 strongly, quadruply lensing systems. In the concordance cosmology, we find $H_0 = 71.8^{+3.9}_{-3.3}\,\mathrm{km}\,\mathrm{s}^{-1}\,\mathrm{Mpc}^{-1}$…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-22 Philipp Denzel , Jonathan P. Coles , Prasenjit Saha , Liliya L. R. Williams

By coupling observations of type Ia supernovae with results obtained from the best available numerical models we constrain the Hubble constant, independently of any external calibrators. We find an absolute lower limit of Ho > 50 km/s/Mpc.…

Astrophysics · Physics 2009-11-10 M. Stritzinger , B. Leibundgut

We generalise the procedure for joint estimation of cosmological parameters to allow freedom in the relative weights of various probes. This is done by including in the joint Likelihood function a set of 'Hyper-Parameters', which are dealt…

Astrophysics · Physics 2007-05-23 Ofer Lahav

The final efforts of the HST Key Project on the Extragalactic Distance Scale are presented. Four distance indicators, the Surface Brightness Fluctuation method, the Fundamental Plane for early-type galaxies, the Tully-Fisher relation and…

Considerable progress has been made in determining the Hubble constant over the past two decades. We discuss the cosmological context and importance of an accurate measurement of the Hubble constant, and focus on six high-precision…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Wendy L. Freedman , Barry F. Madore

The Megamaser Cosmology Project inferred a value for the Hubble constant given by $H_0=73.9 \pm 3.0 $ km/sec/Mpc. This value was obtained using Bayesian inference by marginalizing over six nuisance parameters, corresponding to the…

Instrumentation and Methods for Astrophysics · Physics 2025-06-23 Shubham Barua , Vyaas Ramakrishnan , Shantanu Desai

We present a new method to estimate the Hubble constant H_0 from the measured time delays in quadruply imaged gravitational lens systems. We show how it is possible to get an estimate of H_0 without the need to completely reconstruct the…

Astrophysics · Physics 2009-11-07 V. F. Cardone , S. Capozziello , V. Re , E. Piedipalumbo

A measurement of the expansion rate of the Universe (that is the Hubble constant, H0) is derived here using the gamma-ray attenuation observed in the spectra of gamma-ray sources produced by the interaction of extragalactic gamma-ray…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-19 A. Domínguez , F. Prada
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