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Desi

All articles tagged with #desi

science8 days ago•8 min saved

DESI's 47-Million Galaxy Map Challenges Standard Cosmology

The Dark Energy Spectroscopic Instrument (DESI) has completed its first five-year survey, producing the largest high-resolution 3D map of the universe to date. Covering 47 million galaxies and quasars across 11 billion years of cosmic history, the dataset is six times larger than all previous measurements combined. While the data initially aligned with the standard cosmological model, it required parameter values that differed from expectations, suggesting potential issues with the cosmological constant. This finding, though not yet statistically definitive, has sparked significant debate within the physics community regarding the nature of dark energy and the universe's expansion.

via Gizmodo|

#astronomy #cosmology #dark-energy

science28 days ago•4 min saved

DESI data hint at a more anisotropic universe

A DESI-based analysis of the 3D map of galaxies finds higher anisotropy in the universe’s large-scale structure than predicted by dark-matter–only simulations. The study computes, for each galaxy, how likely it is to find others at various distances and directions, then averages this to gauge directional differences. The result does not imply a cosmic center, but if confirmed it could challenge the assumption of isotropy and point to new physics—such as a time-varying dark energy, revised dark matter behavior, or modified gravity. Verification with DESI DR2 and Euclid data is key as researchers stress-test the findings.

via BBC Sky at Night Magazine|

#anisotropy #cosmology #dark-matter

science28 days ago•135 min saved

Cosmic Clues Suggest Dark Energy May Evolve Over Time

Astronomers compiled a catalog of nearly 3,000 Type Ia supernovae from the Dark Energy Survey and DESI data, finding hints that dark energy’s influence on cosmic expansion may change over time, challenging the standard model that assumes a fixed dark energy. By integrating three decades of observations into a single framework, the study suggests a possible link between gravity and quantum physics and points to future data from the DEBASS program to clarify whether dark energy evolves.

via Space|

#cosmology #dark-energy #desi

science1 month ago•6 min saved

The Universe’s Biggest Map Is Here—and You Can Explore It Online

DESI unveils the largest 3D map of the cosmos, spanning ~75% of the sky with 5.6 trillion pixels and ~4 billion objects; a free Legacy Imaging Surveys viewer lets the public explore the data while scientists study dark energy, with more results and AI-assisted analysis planned for 2027.

via WIRED|

#cosmology #dark-energy #desi

science1 month ago•4 min saved

Cosmic Expansion Gap Grows: Dark Energy May Be Evolving

Two long-standing methods for measuring the universe’s expansion—early-universe data from Planck and local observations of supernovae—remain at odds, a discrepancy known as the Hubble tension. New DESI results, when combined with other probes, hint that dark energy might not be a constant after all, challenging the simplest ΛCDM model. Riess and Leauthaud have warned that the standard cosmology could be cracking, even as some newer analyses (e.g., Lyman-alpha forest data) either align with or complicate this evolving picture. The cosmos’ expansion history thus remains an active, debated frontier.

via All That's Interesting|

#cosmology #dark-energy #desi

space1 month ago•134 min saved

Cosmic atlas maps 4 billion objects in the largest 2D sky survey

An international team released the largest 2D map of the universe, charting about 4 billion objects across three-quarters of the sky, using 13 years of data from the DESI Legacy Imaging Surveys and observations from the Dark Energy Camera (Blanco 4m), Mayall 4m, and Bok 2.3m telescopes, with data supplemented by WISE. The high‑resolution map spans visible and near‑infrared light and will guide future observatories, helping researchers find gravitational lenses, supernovae and dark‑matter/dark‑energy phenomena while informing projects like the Vera C. Rubin Observatory and the Nancy Grace Roman Space Telescope.

via Live Science|

#astronomy #cosmic-map #cosmology

space1 month ago•158 min saved

Cosmic Atlas: 5.6-Trillion-Pixel Map Reveals 4 Billion Objects Across Most of the Sky

Astronomers using the DESI Legacy Imaging Surveys have released the largest 2D map of the universe to date — a 5.6‑trillion‑pixel panorama spanning roughly three‑quarters of the sky and detailing nearly four billion celestial objects. Built from more than 263,000 telescope exposures over a decade and covering visible to near‑infrared wavelengths, the map provides the 2D foundation for DESI’s much larger 3D cosmic map and will aid dark‑energy studies, galaxy evolution research, and training AI systems for future observatories.

via Space|

#astronomy #cosmology #dark-energy

science3 months ago•16 min saved

Cosmic Isotropy Remains Intact as DESI Anomaly Fades with Proper Corrections

A claimed anisotropy in the DESI galaxy survey is shown to be an artifact from not accounting for redshift-space distortions. When comoving distances are used and distortions corrected, the data align with a homogeneous, isotropic universe, reaffirming the cosmological principle and the standard model of cosmology.

via Big Think|

#cosmology #desi #isotropy

science3 months ago•11 min saved

DESI data hint the cosmos isn't uniform at the largest scales

New DESI-based analysis finds directional patterns in the galaxy distribution that persist across billions of light-years, suggesting the universe may not be perfectly uniform on the largest scales. If confirmed, this challenges the cosmological principle and could force revisions to the standard Lambda-CDM model, including possibilities of more complex dark-matter interactions or larger-scale inhomogeneities. The observed patterns are stronger than those produced by simulations, underscoring the need for further data from DESI, Euclid and other surveys to verify the result and guide new theories of cosmic structure.

via The Conversation|

#cosmological-principle #cosmology #dark-matter

science3 months ago•4 min saved

Gigantic Cosmic Structures Challenge Isotropy at Grand Scales

New DESI data analysis finds galaxy distributions forming structures that extend to gigaparsec scales, appearing larger and more coherent than predicted by the standard Lambda-CDM cosmology and indicating persistent directional patterns. While this suggests a potential gap between theory and observation, scientists say there’s no agreed modification to ΛCDM yet; upcoming DESI releases and future surveys from Euclid and the Vera C. Rubin Observatory will help test these surprising findings.

via 404 Media|

#anisotropy #cosmology #desi

space-and-spaceflight4 months ago•17 min saved

Cosmic Acceleration Stands Firm Amid End-of-Universe Debates

A new MNRAS analysis reinforces that the universe’s expansion is still accelerating, countering a recent paper that argued measurement biases could mimic deceleration; after recalibrating for stellar ages, host-galaxy mass, and environmental factors, the results remain consistent with ongoing cosmic acceleration, underscoring the Big Freeze fate while highlighting ongoing scientific scrutiny of dark energy.

via Gizmodo|

#cosmic-acceleration #cosmology #dark-energy

space5 months ago•6 min saved

Five-Year Sky Survey Maps 47 Million Galaxies to Probe Dark Energy

The Dark Energy Spectroscopic Instrument (DESI) completed the most detailed cosmic survey to date, mapping more than 47 million galaxies and quasars across about 14,000 square degrees to create a 3D map of the universe. The dataset aims to test whether dark energy evolves over time and will be analyzed further before broader public access, with future observations planned to extend the coverage and duration into the 2030s.

via The Daily Galaxy|

#astronomy #cosmology #dark-energy

science5 months ago•5 min saved

April’s science images spotlight a detailed 3D map of the universe and other breakthroughs

April’s best science images span cosmic to terrestrial: the DESI project delivers the most detailed 3D map of the universe from 47 million galaxies and quasars, accompanied by Earth-bound highlights such as climate-threatened cherry blossoms in Japan, the discovery of a new endangered Liopholis mutawintji skink in Australia, a lab-grown dinosaur-collagen leather bag, insights into limb regeneration, advanced 3D imaging of coral skeletons with deep learning, and NASA’s Artemis II Moon fly-by with Space Launch System boosters.

via Nature|

#biodiversity #climate-change #desi

space5 months ago•5 min saved

Largest 3D Map of the Universe Deepens Cosmology Puzzle

DESI finished its first official survey, delivering the largest high‑resolution 3D map of the cosmos—47 million galaxies and 20 million stars across 11 billion years—unlocking a data trove that could test the constant nature of dark energy (lambda) and reveal potential evolution. While previous hints suggested possible tensions with the standard model, scientists emphasize careful error analysis and independent confirmation. With six data‑heavy paper batches planned and follow‑on surveys like Euclid and Rubin Observatory on the horizon, the DESI results are likely to refine or challenge current cosmology rather than settle it outright.

via Gizmodo|

#cosmology #dark-energy #desi

science5 months ago•37 min saved

Desi's 47 Million Galaxy Map Reveals the Cosmic Web and Dark Energy’s History

The Dark Energy Spectroscopic Instrument (DESI) at Kitt Peak National Observatory has produced the largest 3D map of the universe, charting about 47 million galaxies and more than 20 million Milky Way stars over a five-year survey. The map uncovers the cosmic web of filaments and voids and enables researchers to track how dark energy has shaped the universe’s expansion over the last 11 billion years, with DESI continuing observations through 2028 to expand the dataset and first full results anticipated in 2027.

via Yahoo|

#cosmic-web #dark-energy #desi