Tag

Anisotropy

All articles tagged with #anisotropy

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

science29 days ago•7 min saved

New analysis hints the universe isn’t accelerating after all

A reanalysis of Pantheon+ Type Ia supernovae, including a correction for the ages of progenitor stars, finds the cosmic expansion may be slowing instead of accelerating and that the apparent acceleration varies with direction. This challenges the dark energy paradigm, though other studies still support acceleration. The Rubin Observatory’s LSST is expected to provide a decisive test with a much larger supernova sample.

via Science Daily|

#anisotropy #cosmic-acceleration #dark-energy

technology2 months ago•32 min saved

SHIFT printing turns hydrogel droplets into aligned microfibers for anisotropic 3D bioprinting

Researchers report SHIFT, a new extrusion-based method that converts discrete hydrogel particles into aligned subvoxel microfibers during printing, producing highly anisotropic fibers (5–30 μm) in situ. Demonstrated with a dual-phase gelatin–poloxamer ink, SHIFT enables integration into 3D bioprinting and microfibre spinning, supporting long myotube formation in vitro and accelerated skeletal muscle regeneration in volumetric muscle loss models.

via Nature|

#3d-printing #anisotropy #hydrogels

space-and-astronomy2 months ago•51 min saved

Cosmic Acceleration May Be an Illusion, Cosmology Faces a Fresh Challenge

New analysis of Type Ia supernovae data, with progenitor-age corrections from the Pantheon+ catalog, suggests the universe’s expansion may be mildly anisotropic and not accelerating uniformly in all directions. If younger supernova progenitors are fainter after standardization, distant observations could mimic acceleration, meaning the apparent cosmic acceleration could be a local, directional effect tied to our motion through the cosmos. This challenges the isotropy assumed in ΛCDM and raises doubts about dark energy's role, while also intersecting with the ongoing Hubble tension between local and early-universe expansion rates.

via Yahoo|

#anisotropy #dark-energy #hubble-tension

science2 months ago•6 min saved

Cosmic Web Suggests Universe Isn’t Uniform at Largest Scales

A DESI-based map of the universe hints at anisotropy: galaxies show directional patterns that persist at gigaparsec scales, challenging the long-held cosmological principle that the cosmos is uniform and isotropic. Results are provocative but require replication with larger datasets before altering models of dark energy/matter.

via Metro.co.uk|

#anisotropy #cosmological-principle #cosmology

science2 months ago•15 min saved

Earth’s Hidden Core Within a Core Revealed by Seismic Echoes

ANU seismologists in 2023 provided evidence that Earth contains an innermost inner core—a roughly 1,300-km-diameter iron sphere with crystal orientation different from the surrounding inner core—reconstructed from global seismic echoes after large earthquakes. This fifth, hidden layer tightens the picture of Earth's deep structure and may reflect an early-formed core or a different iron phase; the same seismic approach is now used to study rocky planets like Mars.

via Space Daily|

#anisotropy #earths-core #innermost-inner-core

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

science5 months ago•8 min saved

Hidden Layer in Earth's Core Could Rewrite Our Understanding of the Planet's Center

Seismic analyses suggest an innermost inner core about 650 kilometers across, forming a distinct central region with different iron-crystal alignment, which may reflect past cooling events and implies Earth's center is more complex than the traditional four-layer model, potentially prompting a rewrite of core formation history.

via SciTechDaily|

#anisotropy #anu #earth-core