Tag

Hubble Constant

All articles tagged with #hubble constant

science1 month ago•60 min saved

Cosmic Speed Limit in Question: Rethinking How Fast the Universe Expands

Quanta Magazine’s The Joy of Why interview with Adam Riess traces how Type Ia supernovae revealed the universe’s accelerating expansion, explains the local vs. early-universe measurements of the Hubble constant, and frames the current Hubble tension that challenges the Lambda-CDM model. Riess discusses how standard candles and redshift work together to map expansion, the role of dark energy (potentially a cosmological constant), and how upcoming observatories like the Nancy Grace Roman Space Telescope, Rubin Observatory, Euclid, and JWST aim to resolve whether the tension signals new physics or hidden systematics.

via Quanta Magazine|

#cosmic-microwave-background #dark-energy #hubble-constant

science1 month ago•4 min saved

Neutron-Star Merger Brings Fresh Data to the Universe's Expansion Rate

An international team combined gravitational-wave data from a neutron-star collision with telescope and astrometric observations to measure the Hubble-Lemaitre Constant via the Cosmic Distance Ladder. Their result adds a late-Universe, gravitational-wave–based data point that loosely aligns with early-Universe (CMB) estimates, highlighting GW methods as a valuable but still less precise tool to help resolve the Hubble tension. More neutron-star mergers are needed to confirm the implications for cosmology.

via Universe Today|

#cosmic-distance-ladder #gravitational-waves #hubble-constant

space3 months ago•8 min saved

Five-image supernova could pin down the universe’s expansion speed

A rare gravitationally lensed, five-image superluminous supernova called SN Winny (SN 2025wny) offers a direct, one-step method to measure the Hubble constant by timing the delays between the multiple light paths, potentially resolving the universe’s expansion-rate disagreement.

via ScienceDaily|

#cosmology #gravitational-lensing #hubble-constant

science4 months ago•3 min saved

New Hubble Constant Precision Keeps Cosmology in Tension

An international team reports the most precise measurement of the Hubble constant to date (about 73.5 km/s/Mpc with ~1% accuracy). While tighter, the result reinforces the long-standing Hubble tension between local measurements and the standard cosmological model, raising the possibility of undiscovered physics or systematic issues and underscoring the need to reassess our understanding of the universe’s expansion.

via Futurism|

#astrophysics #cosmology #hubble-constant

space4 months ago•70 min saved

New Local Distance Network reinforces the Hubble tension, challenging standard cosmology

Space scientists assembled decades of local-universe distance measurements into the Local Distance Network, delivering the most precise direct measure of the Hubble constant to date (73.50 km/s/Mpc with ~1.1% uncertainty) and confirming the ongoing discrepancy between early- and late-universe expansion rates. By anchoring many distance indicators—from parallax stars and megamasers to Cepheids and thousands of galaxies—the study shows the Hubble tension persists, suggesting the standard cosmological model may be incomplete and could point to new physics, with future observatories potentially resolving the difference.

via Live Science|

#cosmology #distance-ladder #hubble-constant

science4 months ago•4 min saved

Cosmic Expansion Seems Faster Than Thought, Sparking Cosmology Questions

A global team using the cosmic distance ladder reports the universe is expanding at about 73.5 km/s per Mpc, faster than the previous ~67, a discrepancy that challenges current cosmology and could reveal gaps in our understanding of dark energy, gravity, or distance measurements.

via VICE|

#astronomy #astrophysics #cosmology

science4 months ago•6 min saved

Unified Measure of Cosmic Expansion Deepens Hubble Mystery

A study in Astronomy & Astrophysics presents the most precise combined value for the Hubble constant, about 73.5 km/s/Mpc (≈45.7 miles/s/Mpc), derived from a new distance-network framework that unifies multiple distance indicators. While it clarifies the measurement, the result reinforces the Hubble tension and suggests that cosmology may require new physics or revisions to current models.

via The Daily Galaxy|

#astronomy-and-astrophysics #cosmology #distance-indicators

space-and-spaceflight4 months ago•17 min saved

Unified Framework Tightens Hubble Constant, Keeps the Tension Alive

Astronomers developed a community-built, open-source distance network that merges local-universe distance measurements to produce a precise Hubble constant of 73.50 ± 0.81 km/s/Mpc. The result confirms, rather than resolves, the existing discrepancy with early-Universe measurements, reinforcing the Hubble tension and hinting at new physics beyond the standard cosmological model. The framework is designed for future testing with next-generation telescopes.

via Gizmodo|

#cosmology #dark-energy #distance-ladder

science4 months ago•7 min saved

Precise local expansion rate deepens the Hubble tension and hints at new physics

An international effort builds a highly precise local measurement of the Hubble constant (73.50 ± 0.81 km/s/Mpc), reinforcing the discrepancy with early-Universe predictions (~67–68) and strengthening the case that the Hubble tension may point to new physics beyond the standard cosmological model.

via ScienceDaily|

#cosmology #dark-energy #distance-ladder

science4 months ago•8 min saved

Constante de Hubble medida con precisión récord de ~1% aviva la posibilidad de nueva física

Un esfuerzo internacional reporta la medición directa más precisa de la tasa de expansión local: la constante de Hubble es 73.50 ± 0.81 km/s/Mpc (~1%), resultado de la red de distancias locales (H0DN) que combina diversas técnicas y datos de NOIRLab (CTIO y KPNO). Este hallazgo refuerza la tensión con las predicciones del Universo temprano, lo que podría indicar nueva física más allá del modelo cosmológico estándar.

via NOIRLab|

#cepheids #h0-tension #hubble-constant

science5 months ago•5 min saved

Gravitational lens splits distant supernova into four images to probe cosmic expansion

A distant Type I superluminous supernova, SN 2025wny at z=2.01, was gravitationally lensed by a foreground galaxy into four images arriving at different times. By analyzing these time delays and light curves, astronomers aim to refine measurements of the universe's expansion and shed light on dark energy, potentially addressing the Hubble tension.

via Indian Defence Review|

#dark-energy #gravitational-lensing #hubble-constant

science5 months ago•42 min saved

Cosmic hum from black hole mergers could refine the universe’s expansion

Physicists propose using the faint, unresolved gravitational-wave background from countless distant black-hole mergers as an independent way to measure the expansion rate of the universe (the Hubble constant), potentially helping resolve the Hubble tension. Even without directly detecting this background, current data already place bounds on H0; upcoming detector upgrades could turn this into a precise measurement, offering a new tool for cosmology while highlighting limitations tied to population models and large uncertainties.

via Yahoo|

#black-holes #cosmology #gravitational-wave-background

science5 months ago•100 min saved

Cosmic hum from black-hole mergers could recalibrate the universe’s expansion

Physicists propose using the faint gravitational-wave background produced by countless distant black-hole mergers as a new, gravity-based method to measure the Hubble constant, offering an independent path to addressing the Hubble tension. Current data already constrain H0 by showing the background’s absence rules out low values; future detector upgrades could turn this into a direct measurement, potentially confirming or challenging existing cosmology without relying on electromagnetic distance ladders or the CMB.

via Live Science|

#cosmology #gravitational-wave-background #gravitational-waves

science5 months ago•6 min saved

Cosmic Gravitational-Wave Hum Tightens the Hubble Constant Bounds

A new method uses the faint gravitational-wave background from unresolved distant black hole mergers—the stochastic siren—to constrain the Hubble constant. By linking merger rates to the observable universe’s size, a stronger background would indicate slower expansion; non-detections thus tighten limits, and when combined with data from individually observed mergers, the approach yields a more precise H0. With future, more sensitive detectors the gravitational-wave background could be detected and used to further refine cosmological measurements, potentially helping resolve the Hubble tension.

via SciTechDaily|

#cosmology #gravitational-waves #hubble-constant

astronomy5 months ago•57 min saved

Cosmic expansion could be measured by the universe's gravitational hum

Scientists propose using the stochastic gravitational-wave background—the faint, background hum from countless distant mergers—to measure the Hubble constant, offering an independent, multi‑messenger approach that could help resolve the long‑standing Hubble tension as gravitational‑wave detectors grow more sensitive.

via Space|

#astronomy #gravitational-waves #hubble-constant