All articles tagged with #cosmology
Two Bell Labs scientists spent about a year tracing a stubborn, omnidirectional hiss in their Holmdel Horn Antenna—scrubbing pigeons and repairing joints—only to recognize the signal as the cosmic microwave background, the afterglow of the Big Bang, a finding that aligned with a Princeton group pursuing the same theoretical prediction.
Cosmic voids—vast, underdense regions in the cosmic web—are becoming powerful cosmological laboratories for gravity, dark energy, and the Hubble tension. New surveys like DESI and Euclid will map tens of thousands to over 100,000 voids with high fidelity, while advanced simulations fill in their evolution. By tracing how galaxies and other tracers move through voids, scientists test gravity theories, study neutrinos, and sharpen our understanding of dark energy. Some researchers even speculate we may live in a colossal supervoid that could help explain the slightly faster local expansion rate, the Hubble tension. The next decade should decisively test these ideas and deepen our view of the universe.
NASA’s James Webb Space Telescope has detected bright, massive galaxies at redshifts around 11–14 (within ~300 million years after the Big Bang) that contain heavy elements like oxygen, challenging standard galaxy-formation timelines. A minority peer‑reviewed paper even suggests a universe age of 26.7 billion years by combining ideas like tired light and time‑varying constants, but the mainstream view remains ~13.8 billion years; the JWST findings continue to test and possibly reshape our cosmological models.
Space Daily revisits Carl Sagan’s Cosmic Calendar, compressing 13.8 billion years into one year—Big Bang on January 1, recorded history ends in the final 12–13 seconds, and a human life is about 0.2 seconds. Ongoing JWST observations and cosmological simulations (COLIBRE/FLAMINGO) are refining the timeline, but the 14-second window remains the core takeaway for perspective on humanity’s place in the cosmos.
Canadian researchers are contributing cryogenic quantum-sensor cameras to the Fred Young Submillimeter Telescope in Chile’s Atacama Desert, a high-altitude instrument designed to map large swaths of the sky in submillimeter wavelengths to study how stars form, how galaxies move, and the nature of dark matter and dark energy. The project involves international partners and will produce terabytes of data processed by dedicated computing centers; first results are expected mid-fall, with public releases about a year later.
A large American Physical Society survey of 1,600+ physicists and science enthusiasts reveals broad disagreement on core cosmology topics. While 68% view the Big Bang as a hot, dense state (not necessarily a definite beginning), 20% see it as the absolute beginning with a singularity. On dark matter, only 10% endorse the traditional WIMP view, with about 21% proposing a hybrid of ideas, and on dark energy, 24% see it as a constant while 26% think it evolves over time, per DESI. The results highlight that scientific consensus is tenuous and progress comes from continued testing and debate.
New cosmological analyses using supernovae, galaxy surveys, and machine-learning reconstructions reveal small but persistent deviations from the standard FLRW description of a uniform, isotropic universe. If confirmed, these effects—potentially driven by Dyer-Roeder light propagation and cosmic backreaction from large-scale structures—could challenge the Lambda-CDM framework and require new physics or revisions of how space-time evolves, with future DESI, Euclid, and other surveys poised to test the results.
Physicists tested a cornerstone of modern cosmology — that the universe is uniform on large scales (FLRW cosmology) — using new diagnostic tests and data from Pantheon+ supernovae, DESI, and baryon acoustic oscillations. They found mild but intriguing deviations (about 2–4 sigma) from standard FLRW predictions, which could point to light propagating through underdense regions (Dyer–Roeder effect) or to the impact of cosmic structure growth (backreaction). The results are preliminary and highly dataset-dependent, so more precise observations are needed to confirm whether the standard cosmological model needs updating.
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.
New simulations indicate the Milky Way sits inside a vast, flattened sheet of matter dominated by dark matter, extending tens of millions of light-years. This planar mass distribution helps explain why nearby galaxies mostly drift away rather than be drawn toward the Milky Way, matching the observed motions of over 30 neighboring galaxies. Further observations will show whether such cosmic sheets are common elsewhere and how they shape galaxy formation.
Using the kinematic Sunyaev-Zeldovich effect on about 686,000 galaxies in clusters 5–7 billion light-years away, researchers measured cluster speeds and found gravity weakens with distance consistent with Newtonian/Einsteinian gravity, strengthening the case for dark matter as the source of anomalous gravitational effects, though many questions remain. The study was published in Physical Review Letters.
A new self-interacting dark matter theory proposes that dark matter particles collide with one another to form dense cores, potentially explaining three puzzling observations: an ultradense dark matter clump in the gravitationally lensed system JVAS B1938+666, a visible “scar” in the GD-1 stellar stream, and the unusual formation of the Fornax 6 star cluster in the Milky Way’s Fornax dwarf galaxy. The mechanism, related to gravothermal collapse, could unify these disparate clues across cosmic scales in a way standard collisionless dark matter cannot.
A new study proposes that tiny energy bursts from decaying dark matter in the early universe could nudge pristine hydrogen gas clouds to collapse faster, facilitating direct-collapse black holes and potentially explaining the unexpectedly early appearance of supermassive black holes seen by JWST. The model highlights axion-like particles in the 24–27 eV range as the right environment to enable rapid formation.
A theoretical team proposes a previously unknown heavy particle that mixes with the Higgs boson to act as a conduit between visible matter and dark matter residing in a warped fifth dimension. This could help explain fermion masses and the dark-to-visible matter ratio, but the particle would be too heavy for current colliders; future machines or gravitational-wave observations might provide indirect evidence.
A new arXiv cosmological model called the axion dark energy (aDE) framework argues that dark energy could evolve rather than stay constant, slowing the expansion until the Universe reverses into a contraction and a Big Crunch roughly 33.3 billion years from now. The model aligns with DES/DESI observations but implies a dramatic shift from the prevailing eternal-acceleration view, underscoring the need for more data to validate or refine this scenario.