arXiv subjects

Victor Edmonds

Publications and source records attributed to Victor Edmonds.

5 recordsLinked to original sources

arXiv2026

Recovering Electron-Distribution Information from the Quiet-Sun Temperature Discrepancy

Temperature diagnostics compress an electron distribution into a scalar. If two diagnostics weight different velocity ranges, their disagreement can retain information either discards. We develop this measurement for the quiet Sun, where radio brightness and scale-height/ionization diagnostics read about 0.6 and 1.5 MK, a ratio of $2.4 \pm 0.3$ stable across eight years. For specified projections, an exact relative-entropy identity partitions the discrepancy: the ratio fixes a family-independent temperature component; residual shape requires a family. Under the $\kappa$ family and stated projection assignments, the ratio gives $\kappa \approx 2.5$ and a free-energy equivalent of 10--20% of the electron thermal energy. An independent EIS within-ion Fe IX test is consistent with $\kappa = 2.5$--3, not confirmed; its confirm condition fired under neither calibration treatment. Under narrow-DEM conditioning, the Maxwellian residual is 2.8 times the conservative systematic floor. A published broad Maxwellian DEM restores spectroscopic consistency, but its material gives a class-level radio-to-EUV cap of 1.21 against the measured class value $2.4 \pm 0.3$. Across all stated treatments, the Maxwellian fails at least one constraint in this class-level joint comparison; the records are neither co-temporal nor co-spatial. Conditional tests, not further evidence, find that the local Coulomb/runaway channel falls 39--56 times short and that a 1.8--3.5 keV stopping-column scale overlaps the inferred 1.7--3 keV sharp-edge bracket. Termination there remains a working hypothesis. The central result is the measurement construction: information lost to either temperature alone becomes recoverable from their disagreement. Direct shape confirmation requires a cross-class or distribution-resolving measurement.

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arXiv2026

The Quiet-Sun DEM Under Kappa: Diagnostic Degeneracy and the Failure of the Conductive Closure

For a plasma whose electrons carry a $\kappa \approx 2.5$ suprathermal tail, the Spitzer-Harm conductive closure does not exist: the conductive flux is the tail-carried third velocity moment, and the local conductivity integral diverges across the entire $\kappa \in [2,3]$ range -- the finite value the closed-form $\kappa$-conductivity returns at $\kappa = 2.5$ is an analytic continuation of a divergent integral, not a physical conductivity. Edmonds (2026a) places the quiet solar corona (QS) in this regime. Taking that as premise, two failures follow for any plasma in the class: the standard EUV-DEM diagnostic cannot resolve such a plasma, and the conductive term of the standard QS energy budget has no valid form. The diagnostic failure is shown end-to-end. A single-T $\kappa = 2.5$ probe, a multi-T $\kappa = 2.5$ source, and a multi-T Maxwellian source, all run through the regularized DEM inversion of Hannah & Kontar (2012), recover $\log T$ widths inside the FWHM distribution the same pipeline returns from 80 real quiet-Sun AIA patches; the pipeline cannot distinguish them. Two structural features also emerge: a Fe XI charge-state crossover and an EUV continuum reversal. The ionization-gated diagnostic structurally returns the tail-weighted effective temperature $T_{\mathrm{eff}}$, while Spitzer-Harm takes the bulk-core $T_{\mathrm{core}} = (\kappa - 3/2)/\kappa \cdot T_{\mathrm{eff}}$ as input. The mismatch invites a temperature substitution yielding a budget reduction -- mechanically correct and physically empty, because the coefficient it corrects has no convergent form: it is the Fourier-law closure itself that fails, not its temperature input. Two QS pillars for impulsive heating -- DEM-width multi-thermality and the conductive-budget gap -- lose their structural assumptions, and the budget question shifts to non-local kinetic transport outside any fluid closure.

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arXiv2026

Multi-diagnostic convergence: a single measurement in weakly collisional plasmas

When multiple electron temperature diagnostics converge on the same value, the standard inference is that the measurement is robust. We show that this convergence is a structural consequence of the shared ionization bottleneck in any plasma where the electron Knudsen number exceeds $\sim 0.01$: all diagnostics downstream of collisional ionization report the effective temperature $T_{\rm eff}$, not the core temperature $T_{\rm core}$. Their agreement is a single measurement reported $N$ times. We introduce a taxonomy: Type A (ionization-gated, $T_{\rm eff}$), Type B (bulk-sampling, $T_{\rm core}$), Type C (distribution-resolving). The ratio $R = T_A/T_B$ yields $\kappa = 3R/[2(R-1)]$ directly. Applied to the solar corona ($R = 2.4$, $\kappa \approx 2.5$) and the tokamak scrape-off layer, single kappa distributions ($\kappa \approx 2$--$10$) reproduce published bi-Maxwellian EEDF decompositions to 3--8\% RMS with one fewer parameter, and Thomson scattering confirms the predicted Type B temperature. We test applicability in planetary nebulae (the 80-year CEL--ORL abundance discrepancy). Knudsen calculations with the Shoub $v^4$ mean-free-path scaling show ionizing electrons are collisionless in the corona even when the bulk is fluid; in PNe, both ionizing ($\sim 55$ eV) and excitation ($\sim 5$ eV) electrons are collisional over nebular scales, identifying PNe as the falsification boundary; in the SOL, non-local parallel transport maintains tails even where local collisionality is high. For $\kappa \approx 3$--$5$, the raw Spitzer--H\"arm formula with spectroscopic $T_e$ overestimates parallel heat flux by factors of 3--25$\times$; flux-limited models inherit the bias through their boundary conditions, relevant to ITER divertor predictions. Every diagnostic campaign on a weakly collisional plasma should include at least one Type B measurement.

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arXiv2026

The Diagnostic Disagreement and the Closure Failure of the Quiet-Sun Corona Are the Same Relative Entropy

In the weakly collisional quiet-Sun corona, the electron distribution departs from Maxwellian, and ``the electron temperature'' is not single-valued: two standard diagnostics differ by a stable factor $R \approx 2.4$ across the solar cycle. We show this departure is a single relative entropy whose two orthogonal components are the EUV--radio diagnostic disagreement and the failure of the local conductive closure. By the generalized Pythagorean identity for Bregman divergences, the relative entropy of the $\kappa \approx 2.5$ distribution from its radio-diagnostic Maxwellian projection ($1.20$ nats) partitions with no cross-term into two components. The first is the energy-matched closure deficit ($0.32$ nats), the information discarded by the local Spitzer--H\"{a}rm closure (Edmonds 2026c), which itself has no convergent form across $\kappa \in [2,3]$. The second is the inter-projection diagnostic gap ($0.876$ nats), what the EUV and radio diagnostics disagree by and a closed-form function of $R$ within the shape envelope. Closure failure and diagnostic disagreement are therefore the same relative entropy in two orthogonal coordinates: together they account for the corona's full departure from Maxwellian. The physical heat flux that survives is non-local and tail-dominated. Any mechanism that sets this $\kappa$ must act on the suprathermal tail, operate non-locally, and fix $\kappa$ to the observed band; of the standalone candidates only velocity filtration (Scudder 1992) meets the first two, and whether it, or anything, fixes $\kappa$ is the open problem we leave posed.

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arXiv2026

The diagnostic temperature discrepancy as evidence for non-Maxwellian coronal electrons

Two independent electron temperature diagnostics applied to the quiet solar corona yield systematically different results. Radio brightness temperatures from the Nancay Radioheliograph indicate T_e ~ 0.6 MK, while hydrostatic scale-height modeling requires T_e ~ 1.5 MK. Both probe electrons; they disagree by a factor of R = 2.4 +/- 0.3. This discrepancy persists across eight years spanning solar minimum and is confirmed by LOFAR at lower frequencies. We consider turbulent scattering, which suppresses brightness temperature, but comparison with the FORWARD/PSIMAS Maxwellian model shows the standard thermal structure predicts ~1.6 MK; scattering accounts for the reduction toward observed MWA values but not the gap to 620 kK. The ratio R is also cycle-invariant despite measured variations in turbulence. We propose the residual discrepancy reflects non-Maxwellian electron velocity distributions. Radio bremsstrahlung samples the distribution core; ionization and scale heights are dominated by the suprathermal tail. For kappa distributions, the predicted ratio kappa/(kappa - 3/2) matches R = 2.4 at kappa ~ 2-3, consistent with spectroscopic measurements in active regions but in tension with perturbative predictions of kappa ~ 10-25. We predict Active Region cores should show a collapsed ratio (R <= 1.5) as collisionality restores thermal equilibrium.

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