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[2026-09-16] · src Stefano Profumo (UC Santa Cruz); arXiv:2609.16425 (2026-09-14)
Fan, Shen, Liang, et al. reported evidence in 2024 (arXiv:2407.11737) for a narrow ~43 GeV gamma-ray line in a stacking analysis of Fermi-LAT data toward the Virgo, Fornax and Ophiuchus clusters - the kind of narrow spectral feature no known astrophysical process produces, which is exactly why a line is treated as a dark-matter smoking gun. Profumo reanalyzes the same public data and the excess survives: it holds up under event-type partitions, a test on data withheld from the original selection, and detector-coordinate permutation tests, and realistic hadronic or inverse-Compton backgrounds are too spectrally broad to fake it. Calibrated across a 20-70 GeV search window and five candidate spatial morphologies, the global significance comes out to roughly 2.7 sigma, peaking at 44.5 GeV under a uniform-surface-brightness template. But a spatial-spectral likelihood analysis - cross-checked with an independent annular analysis - finds the excess events extend through much of each cluster's virial region rather than tracing a centrally peaked profile: smooth NFW annihilation and a central point source are both disfavored, while uniform surface brightness or substructure-boosted annihilation fit the spatial data better.
This is not a retraction - the line is still there in the data, at essentially the same significance it was reported at two years ago. What it rules out is the specific reading that made the line worth a headline: canonical dark-matter annihilation traces the dark-matter density itself, which is centrally peaked (NFW-like) in a cluster, and that is exactly the profile this reanalysis disfavors. A signal spread through the virial region instead is more consistent with cosmic-ray-driven emission from cluster substructure or an instrumental/astrophysical systematic than with a dark-matter particle annihilating where the dark matter actually is densest. The excess itself is still unexplained and still worth tracking, but the dark-matter interpretation that made it interesting to a non-specialist is now the least likely of the candidates on the table - a field correcting its own most exciting reading of a result, which is worth more than another cluster claim would have been.
[2026-09-16] · src Di Pietrantonio, Sokolowski, James, et al.; arXiv:2609.17275 (2026-09-15)
Searching for a fast radio burst below 300 MHz without a target is expensive: the dispersive delay across the band stretches to tens of seconds instead of milliseconds, which makes a blind search with standard incoherent-dedispersion pipelines computationally prohibitive, and until now the only confirmed sub-300-MHz detection came from a LOFAR campaign pointed deliberately at FRB 20180916B, a source already known to repeat at higher frequencies. Di Pietrantonio, Sokolowski, James and 13 co-authors instead ran a wide-field, imaging-based search - no target list, no prior timing information - over 18,244 deg2-hours of Murchison Widefield Array data from the Southern-sky MWA Rapid Two-metre (SMART) survey, about 441 deg2 of usable sky and roughly 41 hours of quality data after cuts, processing around 4 petabytes. They found FRB 20191203A at 138.9-169.6 MHz (centred 154.9 MHz): signal-to-noise 10.7, fluence 360+-30 Jy ms, peak flux density 3.9+-0.6 Jy, dispersion measure 393 pc/cm3 (277 pc/cm3 after subtracting the Milky Way's contribution), implying a maximum redshift of roughly 0.3. Scaled to a 57 Jy ms fluence threshold, the single detection implies a rate of 54 events per sky per day (95% CI: 1-302) - consistent, within those wide bounds, with the rate already measured above 400 MHz.
Every prior non-detection below 300 MHz was equally consistent with two different explanations: low-frequency FRB emission is genuinely rare or suppressed by scattering and absorption near the source, or nobody had searched broadly enough with a technique that could afford to. Those explanations point in opposite directions for what the burst population at this frequency can teach us, and only a non-targeted search could tell them apart. Finding a burst at a rate matching the higher-frequency population on effectively the first unbiased attempt favors the second explanation over the first: the bursts are there, and an imaging-based search that never had to fight the dedispersion cost is a technique that makes the previously impractical experiment - a genuine, unbiased low-frequency FRB survey - practical. That reopens low-frequency observation as a way to probe an FRB's immediate environment through scattering and absorption, rather than a band where the bursts mysteriously fail to show up.
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[2026-09-16] · src —
Alto takes today's slot: three days since its last session is the longest gap of the three instruments right now, and trumpet went yesterday, so the two chops-dependent instruments don't land back to back. With no method book chosen yet, the assignment stays inside the brief's placeholder: long tones, overtones, a scale pattern, nothing invented. Today's fundamental is low A, continuing the upward semitone climb the survey has held since it passed E♭, and the warmup opens breath support's third circuit with the shape that opened the first two -- messa di voce, swelling out and receding back without losing the center at either end. The scale pattern also turns a corner: with every ascending skip up to a seventh already tried, today starts the same interval over again from the top of the scale down, rather than force a wider skip that a single octave has no room left for.
5 minutes: long tones on low A and A♯, whole notes, quarter=60, each note a messa di voce -- two counts at pp, four counts swelling to mf, two counts receding back to pp. The target is whether the return trip to pp is as clean as the start: a swell that comes back thin, sharp or breathy is the embouchure losing the center on the way down, which is the harder half of the exercise and the one this shape is built to test.
Overtone series from fundamental low A: voice up through A–A–E–A–C♯ using only the low A fingering, changing partials with throat and voicing, not embouchure -- the same method as every prior session, now an eleventh semitone higher than where the climb started. Success criterion: three clean ascents in a row, each partial speaking immediately at a steady dynamic, no pinch or pitch smear at the change, and the fundamental still centered after dropping back down each time.
A major scale, one octave, in descending broken thirds from the top: 8–6, 7–5, 6–4, 5–3, 4–2, 3–1. Same interval this survey opened with on 08-26, but started from the octave and resolved downward instead of climbing from the tonic -- find the upper note of each pair first, by ear, rather than reading down a fingering chart. Shape it as a phrase: lean into the first note of each pair and let the second answer it, rather than playing the pattern metronomically.
Stop the moment the messa di voce's return trip to pp goes thin, sharp or breathy instead of staying centered, or an overtone needs a jaw shove or throat squeeze to speak. Both are fatigue standing in for support, and reps past that point train the substitute instead of the real thing.
[2026-09-16] · src —
hearJohnny Hodges — Warm Valley · Tidal · Spotify
Written by Duke Ellington as a feature for Hodges, this ballad is a textbook case of a swell shaped and released without the tone thinning at either end -- exactly the control today's warmup asks a much shorter long tone to manage in miniature. Listen for how a phrase can grow from nearly nothing to full and back again without the pitch drifting or the sound going breathy at the quiet edges; that's the same center today's messa di voce is testing, just held across a whole chorus instead of eight counts.