Tag

Cosmology

All articles tagged with #cosmology

science2 days ago•14 min saved

New Study Proposes 'Cosmic Lockdown' to Prevent Universe from Collapsing into False Vacuum

A new study suggests that quantum decoherence during the early universe’s rapid expansion may have 'locked' fields into their current states, preventing a catastrophic transition to a lower-energy 'true vacuum.' While this 'cosmic lockdown' mechanism offers a potential explanation for why the universe remains stable despite potentially existing in a metastable state, researchers caution that the model is simplified and does not yet confirm the long-term safety of the Higgs field.

via Gizmodo|

#cosmology #decoherence #false-vacuum

science-tech3 days ago•10 min saved

Supercomputer simulations confirm the Milky Way as a prime cosmic location for life

Researchers used the EAGLE supercomputer simulation to map the universe's most habitable regions, finding that the Sun's location in the Milky Way is among the safest and most chemically suitable spots for life. The study identifies 'Goldilocks zones' at galactic and circumstellar levels, avoiding extreme radiation, stellar collisions, and heavy element imbalances. While smaller galaxies are more hazardous, the Milky Way offers a stable environment where life-annihilating events are rare, suggesting our cosmic neighborhood is exceptionally favorable for biological emergence.

via theconversation.com|

#astrobiology #astrophysics #cosmology

science5 days ago•3 min saved

Primordial Magnetic Fields May Resolve Cosmic Expansion Discrepancy

New research suggests that extremely weak magnetic fields from the early universe could explain the discrepancy in measurements of the universe's expansion rate. By simulating how these fields influenced the formation of hydrogen, scientists found that they may have altered the timing of the universe becoming transparent, thereby shifting the inferred value of the Hubble constant. This finding offers a potential solution to the 'Hubble tension' and provides a window into physics at energies unattainable on Earth.

via ScienceDaily|

#cosmic-microwave-background #cosmology #hubble-tension

science6 days ago•120 min saved

MEGATRON Simulation Links First Stars to Milky Way's Chemical Fossils

A new high-resolution simulation called MEGATRON bridges the gap between early universe observations and local stellar chemistry. Led by researchers at the University of Bath, Chicago, and Paris, the project models the formation of the first stars and galaxies from 2023 to 2030. By tracking gas, radiation, and chemical evolution simultaneously, MEGATRON explains how Population III stars enriched the cosmos with heavy elements. The simulation successfully reproduces the 'iron plateau' in dwarf galaxies, suggesting that single massive stellar explosions seeded these systems with iron. This work provides a physical link between James Webb Space Telescope data of distant galaxies and the chemical fingerprints preserved in ancient Milky Way stars.

via Space|

#astrophysics #cosmology #galaxy-formation

science7 days ago•1 min saved

Cosmic Latte: The Beige Hue of the Universe

Astronomers have determined that the average color of the universe is a shade of beige known as 'cosmic latte' (hex code #FFF8E7). This finding, derived from analyzing 200,000 galaxies in the 2dF Galaxy Redshift Survey, indicates that the cosmos has become less blue over the past 10 billion years as redder stars have become more prevalent. The color was named through a public contest, with 'cosmic latte' winning against entries like 'skyvory' and 'univeige.'

via NASA Science (.gov)|

#astronomy #color-science #cosmology

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

science-and-tech10 days ago•24 min saved

New Helium Measurements Resolve Big Bang’s Weakest Evidence

Big Bang nucleosynthesis, historically the least precise of the four pillars of cosmology, has achieved unprecedented accuracy. New data from the LBT Yp Project measures primordial helium abundance to within 0.13%, surpassing previous limits and aligning with cosmic microwave background data.

via bigthink.com|

#big-bang-nucleosynthesis #cosmology #ethan-siegel

science11 days ago

Cosmic Latte: The Beige Average Color of the Universe

via NASA (.gov)|

#astronomy #cosmology #galaxy-survey

science14 days ago•4 min saved

Webb’s Little Red Dots Reveal Rapid Black Hole Growth in the Early Universe

Astronomers are using the James Webb Space Telescope to investigate 'little red dots,' a new class of objects in the early universe that may represent rapidly growing black holes. Recent simulations and observations suggest these objects formed within 500 million to 1.5 billion years after the Big Bang, challenging existing models of how supermassive black holes achieved their size so quickly. While some researchers propose they are 'black hole stars'—black holes enveloped in dense gas cocoons—others remain skeptical, noting that the data does not perfectly fit any single theoretical model.

via Gizmodo|

#astronomy #astrophysics #black-holes

science16 days ago•3 min saved

Simulations link early-universe red dots to rapid black hole growth

Researchers from the Max Planck Institute have published a study in Nature demonstrating that the mysterious 'little red dots' observed by the James Webb Space Telescope are likely the early growth phases of supermassive black holes. Using the ATERUI III supercomputer, the team simulated conditions in the early universe and found that intense ultraviolet radiation from nearby galaxies suppressed normal star formation, allowing massive stars to collapse into heavy black hole seeds. These seeds then accreted matter at super-Eddington rates, growing rapidly into the overmassive black holes seen in JWST data. This model provides a unified explanation for the abundance and properties of these objects without requiring exotic theories.

via Futura, le média qui explore le monde|

#astrophysics #cosmology #james-webb-space-telescope

space17 days ago•8 min saved

Cosmic Acceleration Under Scrutiny: New Supernova Catalog Hints Dark Energy May Evolve

A record 2,884 Type Ia supernovae form the largest catalog to date, integrated with DES data and reanalyzed across telescopes to create a consistent history of cosmic expansion; the results add to hints that dark energy may vary over time, challenging the standard constant-dark-energy model and aligning with DESI signals, with future surveys like DEBASS expected to provide further clarity.

via SciTechDaily|

#cosmology #dark-energy #dark-energy-survey

space21 days ago•121 min saved

Astronomers spot 50 ghost dwarf satellites around three galaxies

Using deep VLT SMASH imaging around three distant galaxies (NGC 5068, 5084, 5087), astronomers identified about 50 faint satellite dwarf galaxies—47 candidates, with only four previously known—ranging from roughly 1 million to 1 billion solar masses and displaying diverse morphologies; the find helps address the cosmological missing-satellites problem and informs how dark matter shapes galaxy halos, with Euclid data expected to confirm them in future releases. The work by Crescenzo Tortora and colleagues was published Sept. 11 in Astronomy & Astrophysics.

via Space|

#cosmology #dark-matter #dwarf-galaxies

astronomy24 days ago•9 min saved

Cosmic Acceleration Persists as New Analysis Reaffirms Dark Energy

An international team finds the universe’s expansion continues to accelerate, refuting a recent claim of slowing growth. By re-calibrating Type Ia supernovae to host galaxy age and mass, the study shows the previous measurements remain robust and dark energy still explains cosmic acceleration; the work counters a South Korean study and reinforces the legacy of Riess, Schmidt and Perlmutter. Published in Monthly Notices of the Royal Astronomical Society.

via SciTechDaily|

#astronomy #cosmic-acceleration #cosmic-expansion

science25 days ago•3 min saved

Physicists Split on Universe’s Biggest Questions, Survey Finds

The largest global survey of physicists reveals little consensus on core questions—from dark matter and black holes to unifying gravity with quantum mechanics and the standard ΛCDM model— with only two items reaching majority support: the Big Bang’s interpretation and cosmic inflation. Views on dark matter, gravity, and cosmology are highly divided, and DESI’s hint that dark energy may vary challenges the standard model. The authors frame this disagreement as opportunity for new data and theory, and an online dashboard lets readers explore the results.

via Science Daily|

#cosmology #dark-matter #physics

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