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While the existence of a non-integer train station platform in the Harry Potter series is a source of delightful whimsy, the reality of electron detectors registering non-integer electrons can be a headache for electron microscopists worried about non-Poisson noise. Although there is no such thing as ¾ of an electron, when an electron enters a pixel in a direct electron detector, the signal energy can spread into neighboring pixels [1], giving a fractional signal. This seemingly innocent effect is a serious problem for Fluctuation Electron Microscopy (FEM) when attempting to correct Poisson noise in low- uence experiments [2]. The Poisson distribution applies strictly to countable discrete events. 

Fluctuation Electron Microscopy (FEM) is a versatile technique for detecting subtle traces of ordering in amorphous and glassy materials [1–4]. However, quantitative results remained elusive, mainly because experimental variance data disagree with theory by several orders of magnitude. The reasons for this discrepancy are still a mystery. We present a preliminary report on what we know. 

Abstract Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame massM> 70M_⊙) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 <e≤ 0.3 at 16.9 Gpc⁻³yr⁻¹at the 90% confidence level.