Researchers developed a way to quantify the fragmented structure of solar flare ribbons, the footprints flares leave in the sun's chromosphere. Applied to an M6.5-class flare observed by IRIS in 2015, it showed ribbon complexity grows with reconnection rate, offering a proxy for hidden coronal processes.
— via Phys.org
Researchers combined a beamstop-free small-angle X-ray scattering method with an X-ray free-electron laser to measure plasma structures from 10 nm to 500 nm in a single pulse with one camera. They tracked laser-driven collapse of silicon rod targets at sub-picosecond resolution, finding that a few nanometers of extra initial plasma size cuts laser absorption to about one-fourth.
— via Phys.org
Northwestern University physicists led by Gerald Gabrielse trapped a single positron in a quantum cyclotron, a Penning trap cooled near absolute zero. The setup could let future work measure its magnetic moment far more precisely, enabling stricter tests of CPT symmetry and the Standard Model.
— via Phys.org
Using the balloon-borne Sunrise-III observatory in 2024, a team led by Japan's NAOJ found thread-like magnetic structures woven through the magnetic canopy above the Sun's quiet regions. Simulations suggest surface motions twist field lines, offering clues to how the solar atmosphere is heated.
— via ScienceDaily
ETH Zurich isotope analysis of NASA's Bennu samples links the asteroid to Ryugu and CI meteorites, suggesting they formed from a mix of inner and outer Solar System dust near the water-ice line, with early Jupiter helping shape that mixing.
— via ScienceDaily
NASA's Psyche spacecraft, having used a Mars gravity assist, is now thrusting almost continuously with its solar-powered Hall-effect system toward the metal-rich asteroid Psyche. It is due to arrive in the main asteroid belt by summer 2029.
— via Phys.org
Lithium fluoride crystal detectors developed in Cracow flew on Artemis I and recorded cosmic radiation near the moon. Results matched conventional track detectors within 15%, and doses there were higher than in Earth orbit, though by less than expected.
— via Phys.org
Physicists built a molecular motor modeled on the Archimedes screw, in which electrons flowing through a helical molecule held between two gold tips make it rotate. The spin direction reverses with voltage polarity, and the rotation raises conductivity by up to two orders of magnitude.
— via Phys.org
Umeå University researchers expected gold nanoparticles to boost light emission in light-emitting electrochemical cells, but found they instead modify electrochemical doping, which governs conductivity. This may offer a new way to control organic electronics, including transistors and bioelectronics.
— via Phys.org
Astronomers using ALMA observations identified a compact core nicknamed the "dragon egg" in the infrared-dark Dragon Cloud, about 16,300 light-years away, that may represent a very early stage of massive star formation. The core holds roughly 20 to 30 solar masses, but the data cannot yet distinguish between competing formation models.
— via Phys.org
A theoretical study in Physical Review D examines whether a black hole could split in two. Entropy normally forbids it, but calculations suggest a narrow loophole for black holes spinning close to their maximum possible rate.
— via Phys.org
Fuzhou University researchers prepared a microwave field in a cat state and used qubits as an artificial environment. With one qubit, interference faded and returned after about 38 nanoseconds, but with eight qubits its return was suppressed during the observation period.
— via Phys.org
Researchers present three methods (AMPS, FLARE, CRISP) that identify the time boundaries of noise glitches in LIGO data, paired with spline and wavelet subtraction techniques. In injection tests on broadband glitches, the combined technique recovered 95 to 97 percent of the injected signal-to-noise ratio, versus about 64 percent for wavelet shrinkage alone.
— via arXiv — Astro-ph, Mohammad Abu Thaher Chowdhury
A Tohoku University-led team studied 13 silicate glass compositions and found that sound velocity is the dominant factor controlling thermal conductivity. Volumetric specific heat and phonon mean free path trade off, so designers may focus on sound velocity, though the link remains untested beyond room temperature and other materials.
— via Phys.org
Using tip-of-the-red-giant-branch measurements for 27 globular clusters, with 24 in the main likelihood, researchers constrain the axion-electron coupling to g_ae below 6.4e-14 at 95% CL. The observed TRGB was fainter than standard cooling predicted, by about 0.078 mag.
— via arXiv — Astro-ph, G. A. Gontcharov, A. M. Kudashov, O. S. Ryutina, S. V. Troitsky
A hep-ph preprint proposes that a weak axion tied to the anomalous U(1)_{B+L} of the Standard Model could account for the scale hierarchies expected of dark energy. Its potential arises from Weinberg operators and a lepton flavor selection rule, and the field would act as thawing quintessence.
— via arXiv — Astro-ph, Pedro Bittar, Carlos E. M. Wagner
Researchers present a way to speed up eccentric effective-one-body models of black hole binary inspirals by averaging away fast orbital oscillations. Inspiral dynamics cost drops by up to two orders of magnitude, overall waveform generation is 1.5-8 times faster, and mismatches stay at or below 8.05e-5.
— via arXiv — Astro-ph, Philip Lynch, Alessandra Buonanno, Aldo Gamboa, Maarten van de Meent
This arXiv paper offers a detailed derivation and critical review of nested sampling, a technique widely used in cosmology and astronomy. It explains the method's strengths and limits and links it to importance sampling and vertical Monte Carlo, serving as both tutorial and review.
— via arXiv — Astro-ph, Luca Martino, Fernando Llorente
A Technion-led team used two-color infrared laser pulses in a scanning tunneling microscope to steer the direction of electron flow across the tip-sample gap. By tuning pulse timing, they reconstructed current bursts of 860 attoseconds while keeping roughly two-nanometer sideways resolution at room temperature and in air.
— via Phys.org
Researchers examined how the neutron-star-cooling limit on the QCD axion mass (KSVZ and DFSZ models) changes when heavier particles such as hyperons and Delta resonances are allowed in the core. The dependence is generally mild, reinforcing the known limit, though in the DFSZ case it may bring the limit into IAXO's sensitivity window.
— via arXiv — Astro-ph, Fernando Arias-Arag'on, Federico Nola
