Related papers: The Hubble Constant
This paper discusses the methodology necessary to measure the Hubble constant Ho to a high degree of accuracy based upon Doppler tracking of spacecraft in the solar system. Using this methodology with available published data we determine a…
In a series of articles, we have shown that the newly discovered plasma-redshift cosmology gives a simpler, more accurate and consistent explanation of many cosmological phenomena than the big-bang cosmology. The SNe Ia observations are in…
Over the past decade, supernovae have emerged as some of the most powerful tools for measuring extragalactic distances. A well developed physical understanding of type II supernovae allow them to be used to measure distances independent of…
Six of the principal galaxy distance indicators are discussed: Cepheid variables, the Tully-Fisher relation, the Dn-sigma relation, Surface Brightness Fluctuations, Brightest Cluster Galaxies, and Type Ia Supernovae. The role they play in…
The direct, empirical determination of the local value of the Hubble constant (H0) has markedly advanced thanks to improved instrumentation, measurement techniques, and distance estimators. However, combining determinations from different…
The Cepheid period-luminosity relation is the primary distance indicator used in most determinations of the Hubble constant. The tip of the red giant branch (TRGB) is an alternative basis. Using the new ANU SkyMapper Telescope, we calibrate…
For the quadruple gravitational lens PG 1115+080, we combine recent measurements of the time delays with new lens models to determine the Hubble constant H_0. We explore the effects of systematic uncertainties in the lens models on the…
The Hubble constant ($H_0$) tension is one of the biggest challenges in modern cosmology. This consists of the discrepancy, at around $5\sigma$, between the local value of $H_0$ measured through Supernovae Ia (SNe Ia) constrained with the…
We determine the distance to 38 clusters of galaxies in the redshift range 0.14 < z < 0.89 using X-ray data from Chandra and Sunyaev-Zeldovich Effect data from the Owens Valley Radio Observatory and the Berkeley-Illinois-Maryland…
We present an improved measurement of the Hubble constant (H_0) using the 'inverse distance ladder' method, which adds the information from 207 Type Ia supernovae (SNe Ia) from the Dark Energy Survey (DES) at redshift 0.018 < z < 0.85 to…
The Hubble constant value is currently known to 10% accuracy unless assumptions are made for the cosmology (Sandage et al. 2006). Gravitational lens systems provide another probe of the Hubble constant using time delay measurements.…
Twenty years after the discovery that the expansion of the Universe is accelerating, a new finding is now challenging our understanding of the cosmos. Recent studies have shown that the Hubble constant, the speed of expansion measured…
In this review, the status of measurements of the matter density (Omega), the vaccuum energy density or cosmological constant (Lambda), the Hubble constant (H0), and ages of the oldest measured objects (t0) are summarized. Measurements of…
A brief history of the determination of the Hubble constant H_0 is given. Early attempts following Lemaitre (1927) gave much too high values due to errors of the magnitude scale, Malmquist bias and calibration problems. By 1962 most authors…
There are irreducible differences between the Hubble constant measured locally and the global value. They are due to density perturbations and finite sample volume (cosmic variance) and finite number of objects in the sample (sampling…
The Hubble constant inferred from the 6-parameter fit to the CMB power spectrum conflicts with the value obtained from direct measurements via type Ia supernova and Cepheids observations. We write down effective operators involving spin-0,…
The bias in the determination of the Hubble parameter and the Hubble constant in the modern Universe is discussed. It could appear due to statistical processing of data on galaxies redshifts and estimated distances based on some statistical…
A linearity test shows H_0 to decrease by 7% out to 18000 km/s. The value at 10000 km/s is a good approximation to the mean value of Ho over very large scales. The construction of the extragalactic distance scale is discussed. Field…
We assess the robustness of the two highest rungs of the "cosmic distance ladder" for Type Ia supernovae and the determination of the Hubble-Lema\^itre constant. In this analysis, we hold fixed Rung 1 as the distance to the LMC determined…
1. We find that any two distance moduli measurements for the same galaxy differ from each other by 2.07 times the reported one sigma uncertainty on average. 2. This average difference between distance moduli measurements of the same galaxy…