All articles tagged with #cosmology
The piece argues that the 'reality' of a multiverse hinges on definition: while quantum mechanics’ many-worlds view and string theory’s landscape offer frameworks in which multiple universes could exist, there is no direct evidence for other universes. Indirect hints might come from how these theories predict physics at tiny scales or high-energy experiments, but proving a multiverse remains elusive.
A LIGO detection involving an object lighter than a solar mass challenges standard stellar-black-hole formation, with researchers proposing a primordial black hole created in the early universe as the explanation. If confirmed, PBHs could account for dark matter, but further detections and next‑gen observatories like LISA and Cosmic Explorer are needed to build stronger evidence.
Space.com reports on MadEvolve, an AI framework that uses Large Language Models as mutation operators within evolutionary programming to iteratively mutate and improve cosmology code. By evaluating new program variants with physics-based metrics, it has delivered substantial gains over human-crafted baselines—such as reconstructing the universe’s initial conditions—and even uncovered thousands of anomalies in archival Hubble data. Built as a general framework, MadEvolve could extend to other scientific fields, signaling a future where AI acts as a tireless, collaborative researcher in astronomy and beyond.
Two studies of the Centaurus A and M81 galaxy groups estimate a local Hubble constant around 64 km/s/Mpc, slower than some nearby measurements and closer to the CMB/LCDM value, suggesting less dark matter may be needed and that the Hubble tension could be mitigated by analyzing more galaxy groups with upcoming 4MOST data.
New simulations using 31 isolated nearby galaxies show the Milky Way sits in a pancake-shaped sheet of dark matter extending up to ~10 Mpc. This structure naturally explains the Local Sheet, Local Void, and the quiet Hubble flow within ΛCDM, without new physics, per Wempe et al. in Nature Astronomy.
Astronomers used line-intensity mapping from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) to create a 3D map of the early universe, revealing a vast ‘sea of light’ from hydrogen Lyman-alpha emission that traces galaxy and gas distributions 9–11 billion years ago. The work helps probe gravity and dark energy’s role in cosmic evolution, leveraging hundreds of millions of spectra; further noise-reduction advances will enable mapping even fainter structures and tighten cosmological constraints.
Researchers using computer simulations reveal the Local Group sits in a vast, flat sheet of matter—dominated by dark matter—with large voids above and below. This structure counteracts the Milky Way–Andromeda gravity, causing nearby galaxies to recede rather than fall inward and producing a virtual twin of our cosmic neighborhood that matches the observed positions and speeds of galaxies just outside the Local Group.
Vienna University of Technology researchers derive a q-desic equation by quantizing the spacetime metric in a simple gravitational field, predicting that quantum spacetime can subtly alter particle trajectories. The deviations are minuscule on small scales, but when the cosmological constant is included they become significant at cosmological distances, potentially offering an observable to test and distinguish quantum gravity theories using astronomical data.
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.
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.
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.
AIP Advances paper by Maria Strømme proposes that consciousness is the foundational field from which time, space, and matter emerge, with individual minds as expressions of a universal consciousness. The theory aims to unite quantum physics with non-dual philosophy, offering testable predictions across physics, neuroscience, and cosmology, and even suggests personal identity survives death within the field. While mathematically framed, it is not yet experimentally confirmed and remains controversial, challenging materialist views and awaiting proof.
New research argues Einstein–Rosen bridges are not spatial shortcuts but two-directional structures in time, acting as complementary halves of a quantum state with forward and backward arrows of time. This framework preserves information across horizons, offering a natural resolution to the black hole information paradox without new physics and suggesting the Big Bang could be a quantum bounce between time-reversed phases. While it does not imply traversable wormholes, the idea points to a deeper quantum gravity picture and potential observational hints such as remnants in the cosmic microwave background or relic black holes.
An international collaboration unified multiple distance-measurement methods into a single statistical framework, achieving a 1% precise measurement of the Hubble constant—the most accurate value to date. While the improved precision narrows uncertainties, it does not resolve the ongoing tension with early-universe predictions, underscoring the need for new physics or modifications to current cosmological models.
Stephen Hawking, diagnosed with ALS at 21, defied doctors by living roughly 55 years beyond expectations, making landmark contributions to black holes (Hawking radiation) and cosmology, penning the bestseller A Brief History of Time, and becoming a global icon of science communication despite paralysis.