#hubble-constant — Public Fediverse posts
Live and recent posts from across the Fediverse tagged #hubble-constant, aggregated by home.social.
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The Local Distance Network - A community consensus report on the measurement of the #HubbleConstant at ∼1% precision: https://www.aanda.org/component/article?access=doi&doi=10.1051/0004-6361/202557993 - the result is 73.5+/-0.8 (essentially 74, as I've said for years :-) km/s/Mpc, in huge tension with the CMBR -> A community-built distance network sharpens the Hubble constant and broadens the evidence behind the “Hubble tension” / The Local Universe’s Expansion Rate Is Clearer Than Ever, but Still Doesn’t Add Up: https://www.issibern.ch/hubble-constant-press-release/ / https://noirlab.edu/public/news/noirlab2611/?lang
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Cosmological Models Are In Trouble After Recent Studies on Dark Energy - YouTube
https://www.youtube.com/watch?v=NK-4TViTilU -
The Stochastic Siren - Astrophysical Gravitational-Wave Background Measurements of the #HubbleConstant: https://arxiv.org/abs/2503.01997 -> Illinois and UChicago physicists develop a new method to measure the expansion rate of the universe: https://physics.illinois.edu/news/Hubble-tension-expansion-rate-of-universe
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Munich astronomers imaged and modelled an exceptionally rare #supernova that could provide a new, independent way to measure how fast the #universe is expanding: http://go.tum.de/991366 🌌
#hubbleconstant #cosmicexpansion #cosmology #astrophysics
📷C. Saulder
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Join us for the latest lecture of "Wissenschaft für Alle"!
What is the #HubbleConstant and how is it determined? Find out with Andreas Flörs (GSI/FAIR) 🌌
German only.Online or on site as usual: Wednesday, 25 February 2026, 2 PM
Online event: https://gsi-fair.zoom.us/j/98465545116#success
Meeting-Code: wfa
On site registration: https://indico.gsi.de/event/23430/registrations/7199/
Location: GSI/FAIR #Darmstadt© NASA, ESA, CSA, STScI
#lecture #science #WissenschaftfürAlle #WfA #particleaccelerator #space -
So I’m reading an article in New Scientist about problems nailing down the #HubbleConstant and I thought, if the universe is expanding, as in adding new space where there already is some, why isn’t everything expanding with it? All I can think of is, it’s gravity doing it, keeping localized bits of matter together, from subatomic particles to galaxies in size, essentially fighting an epic, mythic battle against The Expansion. Which side are dark energy & dark matter on?
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Prof. Wendy Freedman recognized with 2026 Franklin Institute Award in Physics
Pioneering cosmologist honored for landmark measurements of the Hubble Constant.
https://news.uchicago.edu/story/prof-wendy-freedman-recognized-2026-franklin-institute-award-physics
#Cosmology #WendyFreedman #HubbleConstant #Astronomy #Astrophysics #Astrodon #science #news #UChicago
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Carnegie Supernova Project - Fast-Declining Type Ia Supernovae as Cosmological Distance Indicators: https://arxiv.org/abs/2509.07093 -> thread https://x.com/DScol/status/1965783510469546370 -> the #HubbleConstant is ... 75!
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The Perfect Host: JWST Cepheid Observations in a Background-Free SN Ia Host Confirm No Bias in Hubble-Constant Measurements
by Adam Riess and co-authors
https://arxiv.org/abs/2509.01667 -
in the #arXiv
Prior-free cosmological parameter estimation of Cosmicflows-4
The analysis suggests a Hubble constant value of 75.8±0.4 km/s /Mpc, exacerbating (or independently confirming) the existing "Hubble Tension".
by Chaimongkol Duangchan and co-authors
https://arxiv.org/abs/2507.22236#Cosmology #Cosmicflows #HubbleConstant #HubbleTension #Astrophysics #Astrodon #galaxies #physics #science
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Webb telescope helps refines Hubble constant, suggesting resolution rate debate
https://phys.org/news/2025-05-webb-telescope-refines-hubble-constant.html
#HackerNews #WebbTelescope #HubbleConstant #SpaceScience #Astronomy #News #Debate
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The Complete Sample of Available SNe Ia Luminosity Calibrations from the TRGB Observed with either HST or JWST: https://arxiv.org/abs/2504.08921 (spoiler: the 'local' #HubbleConstant is really 72 to 73 km/s/Mpc) -> thread https://x.com/DScol/status/1912184923894526047
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Do ongoing tensions leave room for new physics?
One century after Edwin Hubble revealed his astonishing discovery of a cosmos beyond the Milky Way, the most precise measurements still can’t agree on how fast galaxies are moving.
By Wendy Freedman
https://www.nature.com/articles/d41586-025-00896-5#HubbleTension #HubbleConstant #Physics #Astronomy #Astrophysics #Astrodon #Science #STEM
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Turning the #Hubble tension into a crisis: New measurement confirms #universe is expanding too fast for current models
The universe is expanding faster than predicted by theoretical models, and faster than can be explained by our current understanding of #physics.
They arrived at a value for the #HubbleConstant of 76.5 kilometers per second per megaparsec which matches existing measurements, but not as our current understanding of physics predicts it.
https://phys.org/news/2025-01-hubble-tension-crisis-universe-fast.html -
How fast is the Universe expanding? This astronomer took cosmology closer to an answer
Wendy Freedman is part of Nature’s 10, a list of people who shaped science in 2024.
https://www.nature.com/articles/d41586-024-03899-w
#Cosmology #HubbleTension #HubbleConstant #Science #Nature #astronomer #astronomi #astrophysics #STEM #WomeninSTEM #Womeninscience #Universe
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JWST Validates HST Distance Measurements - Selection of Supernova Subsample Explains Differences in JWST Estimates of Local H0: https://iopscience.iop.org/article/10.3847/1538-4357/ad8c21 -> Webb telescope's largest study of universe expansion confirms challenge to cosmic theory: https://hub.jhu.edu/2024/12/09/webb-telescope-hubble-tension-universe-expansion/preview/ - the findings offer a crucial cross-check for previous Hubble Space Telescope measurements of the universe's mysterious expansion. #HubbleConstant
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Webb Researchers Discover Lensed Supernova, Confirm Hubble Tension
#Cosmology #JWST #HubbleConstant #HubbleTension #Universe #Astrodon #science #news
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On France Culture today: The Hubble Tension
... in an interview by the excellent Celine Loozen I talk about our Cosmicflows-4 measurement of the Hubble Constant, as well as the value inferred from Ho'oleilana, that are both exacerbating the tension.
▶ at t=33:30 https://www.radiofrance.fr/franceculture/podcasts/la-science-cqfd/constante-de-hubble-la-tension-monte-7710009
#Cosmology #Hubble #HubbleConstant #HubbleTension #Hooleilana #science #Astrodon
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in the #arXiv
DESI Peculiar Velocity Survey – Fundamental Plane
by Khaled Said and co-authors
https://arxiv.org/abs/2408.13842#Cosmology #galaxies #cosmicflows #astronomy #astrophysics #astrodon #science #STEM #DESI #FundamentalPlane #HubbleConstant #TullyFisher
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Status Report on the Chicago-Carnegie Hubble Program (CCHP) - Three Independent Astrophysical Determinations of the #HubbleConstant Using the James Webb Space Telescope: https://arxiv.org/abs/2408.06153 -> Space telescope data reignite debate over how fast universe is expanding—and whether ‘new physics’ is needed: https://www.science.org/content/article/space-telescope-data-reignite-debate-over-how-fast-universe-expanding-and-whether-new - triple measurement of the Hubble constant using JWST suggests unidentified biases may account for disparate results.
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Difference ways of measuring the Hubble Constant still don't agree with each other, yet.
"A long-awaited study of the cosmic expansion rate suggests that when it comes to the Hubble tension, cosmologists are still missing something."
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Back in April I posted about a meeting at the Royal Society in London called Challenging the Standard Cosmological Model, some of which I attended virtually. In that post I mentioned that Wendy Freedman gave a talk related to the ongoing issue of the Hubble Tension, i.e. the discrepancy between different types of measurement of the Hubble Constant, usually characterized as local measurements (using stellar distance indicators) and larger-scale measurements (chiefly Planck). There are quite a few posts about this issue on this blog. Anyway, Wendy Freedman mention in her talk that her latest work on stellar distances suggested a value of 69.1 ± km s-1 Mpc-1, which reduces the tension with Planck significantly. At the time, however, there was no paper explaining how this number was derived.
Yesterday there appeared on arXiv a preprint by Freedman et al. which summarizes the recent results. The abstract is here:
We present the latest results from the Chicago Carnegie Hubble Program ( CCHP) to measure the Hubble constant using data from the James Webb Space Telescope (JWST). This program is based upon three independent methods: (1) Tip of the Red Giant Branch (TRGB) stars, (2) JAGB (J-Region Asymptotic Giant Branch) stars, and (3) Cepheids. Our program includes 10 nearby galaxies, each hosting Type Ia supernovae (SNe Ia), suitable for measuring the Hubble constant (H0). It also includes NGC 4258, which has a geometric distance, setting the zero point for all three methods. The JWST observations have significantly higher signal-to-noise and finer angular resolution than previous observations with the Hubble Space Telescope (HST). We find three independent values of H0 = 69.85 ± 1.75 (stat) ± 1.54 (sys) for the TRGB, H0 = 67.96 ± 1.85 (stat) ± 1.90 (sys) km s-1 Mpc-1 for the JAGB, and H0 = 72.05 ± 1.86 (stat) ± 3.10 (sys) for Cepheids. Tying into SNe Ia, and combining these methods adopting a flat prior, yields our current estimate of H0 = 69.96 ± 1.05 (stat) ± 1.12 (sys) km s-1 Mpc-1. The distances measured using the TRGB and the JAGB method agree at the 1% level, but differ from the Cepheid distances at the 2.5-4% level. The value of H0 based on these two methods with JWST data alone is H0 = 69.03 ± 1.75 (total error) km s-1 Mpc-1. These numbers are consistent with the current standard ΛCDM model, without the need for the inclusion of additional new physics. Future JWST data will be required to increase the precision and accuracy of the local distance scale.
You can read the full paper on arXiv here. A summary of the summary is that of the three methods they use, two give lower values of the Hubble constant and one (Cepheids) gives a higher value but with larger errors. The number quoted in the Royal Society talk was presumably preliminary as it doesn’t match any of the numbers in the abstract, but the point remains.
You can see the reduction in scatter in the new JWST measurements in this Figure (old on the left and new on the right).
On the face of it, these results suggest that the Hubble tension is greatly reduced. I am sure, however, that advocates of a higher value will have been preparing their ripostes and it’s just a matter of time before they arrive on the arXiv too!
https://telescoper.blog/2024/08/14/hubble-tension-reduced/
#arXiv240806153 #HubbleConstant #HubbleTension #JWST #WendyFreedman
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Everything you wanted to know about The Hubble Constant Tension
Editors Eleonora Di Valentino, Dillon Brout
https://link.springer.com/book/10.1007/978-981-99-0177-7
#Cosmology #HubbleTension #HubbleConstant #Astronomy #Astrophysics #Astrodon #science #STEM #book #sciencebook
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A Population II TRGB-SBF Route to H0 with HST and JWST
by Brent Tully, tomorrow at @astroIAP
http://www.iap.fr/vie_scientifique/journal-clubs/resumes.php?nom_seminaire=Journal-club%20Univers&numero=4427#BrentTully #HubbleConstant #Cosmology #universe #Hubble #space #telescope #HST #JWST #galaxies #astronomy #astrophysics #astrodon #science #seminar #conference #news #Paris #IAP #astroIAP #STEM
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Introducing the Mass Hyperplane (MH), to measure the peculiar velocities of 2496 galaxies at z < 0.12 from the GAMA sample
by Mustafa Burak Dogruel and co-authors
https://arxiv.org/abs/2405.10866#Cosmology #galaxies #MassHyperplane #TullyFisher #FundamentalPlane #cosmicflows #PeculiarVelocities #Hubble #HubbleConstant #GAMA #arXiv #astroph #astronomy #astrophysics #astrodon #science #STEM
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#FredAdams - #Ultimate #Questions: Do They #Evolve?
https://www.youtube.com/watch?v=ozKhWgTYAkw
#Philosophy #PhilosophyOfScience #Science #PhilosophyOfCosmology #Cosmology #Omega #Universe #CosmologicalConstant #Hubble #HubbleConstant #Expansion #BigBang #Astronomy #Astrophysics #Dark Energy #DarkMatter #Multiverse #CloserToTruth #RobertKuhn
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Bulk Flow Motion Detection in the Local Universe with Pantheon+ Type Ia Supernovae
... with a new measurement of the Hubble Constant.
by Maria Lopes, Armando Bernui, Camila Franco, and Felipe Avila
https://iopscience.iop.org/article/10.3847/1538-4357/ad3735 #openaccess
#cosmology #bulkflow #supernovae #HubbleConstant #DipoleRepeller #SouthPoleWall #astronomy #astrophysics #astrodon
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World’s top cosmologists convene to question conventional view of the universe
Meeting at London’s Royal Society will scrutinise basic model first formulated in 1922 that universe is a vast, even expanse with no notable features.
#cosmology #conference #London #RAS #universe #astronomy #astrophysics #astrodon #science #bigring #galaxies #HubbleConstant