cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Tycho-Gaia astrometric solution. How to get 2.5 million parallaxes with less than one year of Gaia data
Creators: name: Michalik, Daniel
name: Lindegren, Lennart
name: Hobbs, David
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. The first release of astrometric data from Gaia will contain the mean stellar positions and magnitudes from the first year of observations, and proper motions from the combination of Gaia data with Hipparcos prior information (HTPM). Aims. We study the potential of using the positions from the Tycho-2 Catalogue as additional information for a joint solution with early Gaia data. We call this the Tycho-Gaia astrometric solution (TGAS). Methods. We adapt Gaia's Astrometric Global Iterative Solution (AGIS) to incorporate Tycho information, and use simulated Gaia observations to demonstrate the feasibility of TGAS and to estimate its performance. Results. Using six to twelve months of Gaia data, TGAS could deliver positions, parallaxes and annual proper motions for the 2.5 million Tycho-2 stars, with sub-milliarcsecond accuracy. TGAS overcomes some of the limitations of the HTPM project and allows its execution half a year earlier. Furthermore, if the parallaxes from Hipparcos are not incorporated in the solution, they can be used as a consistency check of the TGAS/HTPM solution.
description: Accepted for publication in A&A, 24 Dec 2014
Toward more accurate RR Lyrae metallicities
Creators: name: Kovacs, Geza
name: Jurcsik, Johanna
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: By using a large sample of published spectroscopic iron abundances, we point out the importance of gravity correction in deriving more accurate metal abundances for RR Lyrae stars. For the 197 stars with multiple spectra we find overall [Fe/H] standard deviations of 0.167 (as published), 0.145 (shifted by data source zero points) and 0.121 (both zero point-shifted and gravity-corrected). These improvements are significant at the ~2 sigma level at each correction step, leading to a clearly significant improvement after both corrections applied. The higher quality of the gravity-corrected metallicities is strongly supported also by the tighter correlation with the metallicities predicted from the period and Fourier phase phi_31. This work underlines the need for using some external estimates of the temporal gravity in the chemical abundance analysis rather than relying on a full-fetched spectrum fit that leads to large correlated errors in the estimated parameters.
description: Submitted to A&A. After the 2nd (less negative/almost positive) referee report. 1.2Mb, 10 pages (7+3 with appendices). Aesthetic old-fashioned references with clickable ADS links
Extrapolating an Euler class
Creators: name: van der Kallen, Wilberd
Publisher: name: arXiv
Year: 2015
Subjects: subject: K-Theory and Homology (math.KT)
subject: FOS: Mathematics
subject: 19E20

description: Let $R$ be a noetherian ring of dimension $d$ and let $n$ be an integer so that $n \leq d\leq 2n-3$. Let $(a_1,...,a_{n+1})$ be a unimodular row so that the ideal $J=(a_1,...,a_n)$ has height $n$. Jean Fasel has associated to this row an element $[(J,ω_J)]$ in the Euler class group $E^n(R)$, with $ω_J:(R/J)^n\to J/J^2$ given by $(a_1,...,a_{n-1},a_n a_{n+1})$. If $R$ contains an infinite field $F$ then we show that the rule of Fasel defines a homomorphism from $WMS_{n+1}(R)=Um_{n+1}(R)/E_{n+1}(R)$ to $E^n(R)$. The main problem is to get a well defined map on all of $Um_{n+1}(R)$. Similar results have been obtained by Mrinal Kanti Das and MD Ali Zinna, with a different proof. Our proof uses that every Zariski open subset of $SL_{n+1}(F)$ is path connected for walks made up of elementary matrices.
description: 7 pages, reference updated
Reality Check: The Development of RDA: A View from the Trenches
Creators: name: Glennan, Kathy
Publisher: name: Media Periodicals Division, The Kansas City Gardener, Inc.
Year: 2022
Subjects: RDA: Resource Description and Access
RDA Steering Committee
Descriptive cataloging
Cataloging rules

description: Kathy Glennan (RDA Steering Committee Chair 2019-2022) describes her engagement with the development of RDA: Resource Description and Access over the past two decades, how it has shaped her career, increased her understanding of international standards development, and changed her perspective of what a cataloging code should look like.
General three-state model with biased population replacement: Analytical solution and application to language dynamics
Creators: name: Colaiori, Francesca
name: Castellano, Claudio
name: Cuskley, Christine F.
name: Loreto, Vittorio
name: Pugliese, Martina
name: Tria, Francesca
Publisher: name: arXiv
Year: 2014
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Physics and Society (physics.soc-ph)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Empirical evidence shows that the rate of irregular usage of English verbs exhibits discontinuity as a function of their frequency: the most frequent verbs tend to be totally irregular. We aim to qualitatively understand the origin of this feature by studying simple agent--based models of language dynamics, where each agent adopts an inflectional state for a verb and may change it upon interaction with other agents. At the same time, agents are replaced at some rate by new agents adopting the regular form. In models with only two inflectional states (regular and irregular), we observe that either all verbs regularize irrespective of their frequency, or a continuous transition occurs between a low frequency state where the lemma becomes fully regular, and a high frequency one where both forms coexist. Introducing a third (mixed) state, wherein agents may use either form, we find that a third, qualitatively different behavior may emerge, namely, a discontinuous transition in frequency. We introduce and solve analytically a very general class of three--state models that allows us to fully understand these behaviors in a unified framework. Realistic sets of interaction rules, including the well-known Naming Game (NG) model, result in a discontinuous transition, in agreement with recent empirical findings. We also point out that the distinction between speaker and hearer in the interaction has no effect on the collective behavior. The results for the general three--state model, although discussed in terms of language dynamics, are widely applicable.
description: 14 pages, 6 figures. Final published version
Zur Priesterfrage an der Bischofssynode 1971
Creators: name: Balthasar, Hans Urs Von
Publisher: name: Internationale katholische Zeitschrift Communio
Year: 2022

description: Internationale katholische Zeitschrift Communio, Bd. 1 Nr. 1 (1972): Internationale katholische Zeitschrift Communio, Band 1, Heft 1
Simulation on system configuration for stationary head CT using linear carbon nanotube x-ray source arrays
Creators: name: Luo, Y.
name: Zhou, O.
name: Lee, Y.Z.
name: Lu, J.
name: Spronk, D.
Publisher: name: SPIE
Year: 2021

description: Purpose: The invention of carbon nanotube (CNT) x-ray source arrays has enabled the development of novel imaging systems, including stationary tomosynthesis and stationary computed tomography (CT) with fast data acquisition, mechanically robust structures, and reduced image blur from source-detector motion. In this work, we report the results of simulation studies of potential system configurations for a stationary head CT (s-HCT) using linear CNT x-ray sources and detector arrays. Approach: We explored s-HCT configurations that utilize one, two, and three linear CNT source arrays. Simulations were implemented using three digital phantoms with both CPU and GPU computing. Sinogram coverage was used for qualitative evaluation of the CT projection collection efficiency for each configuration. A modified low-contrast Shepp-Logan (SL) phantom was implemented for image quality assessment using quantitative metrics. Different iterative reconstruction (IR) methods were compared with both qualitative and quantitative assessments. Results: Sinogram coverage of s-HCT configurations was sensitive to the number of CNT source arrays and geometry. The simulations suggest that a s-HCT configuration with three planes gives near complete sinogram coverage. Such a configuration enables accurate reconstruction of the low-contrast SL phantom and considerably diminished artifacts caused by the system geometry. Conclusions: An optimized s-HCT system configuration with three linear CNT x-ray source arrays is feasible. IR algorithms can diminish artifacts caused by sparse and asymmetrical scans. The proposed s-HCT system configuration is currently under construction.
A three-component giant radio halo: the puzzling case of the galaxy cluster Abell 2142
Creators: name: Bruno, L.
name: Botteon, A.
name: Shimwell, T.
name: Cuciti, V.
name: de Gasperin, F.
name: Brunetti, G.
name: Dallacasa, D.
name: Gastaldello, F.
name: Rossetti, M.
name: van Weeren, R. J.
name: Venturi, T.
name: Russo, S. A.
name: Taffoni, G.
name: Cassano, R.
name: Biava, N.
name: Lusetti, G.
name: Bonafede, A.
name: Ghizzardi, S.
name: De Grandi, S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Turbulence introduced into the intra-cluster medium (ICM) through cluster merger events transfers energy to non-thermal components, and can trigger the formation of diffuse synchrotron radio sources. Typical diffuse sources in the forms of giant radio halos and mini-halos are found in merging and relaxed cool core galaxy clusters, respectively. On the other hand, recent observations have revealed an increasing complexity of the non-thermal phenomenology. Abell 2142 (A2142) is a mildly disturbed cluster that exhibits uncommon thermal and non-thermal properties. It is known to host a hybrid halo consisting of two components (H1 and H2), namely a mini-halo-like and an enigmatic elongated radio halo-like structure. We aim to investigate the properties, origin, and connections of each component. We present deep LOFAR observations of A2142 in the frequency ranges $30-78$ MHz and $120-168$ MHz. With complementary multi-frequency radio and X-ray data, we analyse the radio spectral properties of the halo and assess the connection between the non-thermal and thermal components of the ICM. We detected a third radio component (H3), which extends over the cluster volume on scales $\sim 2$ Mpc, embeds H1 and H2, and has a morphology that roughly follows the thermal ICM distribution. The radio spectral index is moderately steep in H1 ($α=1.09\pm 0.02$) and H2 ($α=1.15\pm 0.02$), but is steeper ($α=1.57\pm 0.20$) in H3. The analysis of the thermal and non-thermal properties allowed us to discuss possible formation scenarios for each radio component. Turbulence from sloshing motions of low-entropy gas on different scales may be responsible for the origin of H1 and H2. We classified H3 as a giant ultra-steep spectrum radio halo, which could trace the residual activity from an old energetic merger and/or inefficient turbulent re-acceleration induced by ongoing minor mergers.
description: 24 pages (including Appendix), 15 Figures (plus 4 Figures in Appendix), Accepted for publication by A&A
Feasibility of a prototype carbon nanotube enabled stationary digital chest tomosynthesis system for identification of pulmonary nodules by pulmonologists
Creators: name: Lee, Y.Z.
name: Sakthivel, M.
name: Akulian, J.
name: Ghosh, S.
name: MacRosty, C.R.
name: Belanger, A.
name: Zhou, O.
name: Burks, A.C.
name: Benefield, T.S.
name: Inscoe, C.R.
name: Lu, J.
Publisher: name: AME Publishing Company
Year: 2022

description: Background: Screen detected and incidental pulmonary nodules are increasingly common. Current guidelines recommend tissue sampling of solid nodules >8 mm. Bronchoscopic biopsy poses the lowest risk but is paired with the lowest diagnostic yield when compared to CT-guided biopsy or surgery. A need exists for a safe, mobile, low radiation dose, intra-procedural method to localize biopsy instruments within target nodules. This retrospective cross sectional reader feasibility study evaluates the ability of clinicians to identify pulmonary nodules using a prototype carbon nanotube radiation enabled stationary digital chest tomosynthesis system. Methods: Patients with pulmonary nodules on prior CT imaging were recruited and consented for imaging with stationary digital chest tomosynthesis. Five pulmonologists of varying training levels participated as readers. Following review of patient CT and a thoracic radiologist’s interpretation of nodule size and location the readers were tasked with interpreting the corresponding tomosynthesis scan to identify the same nodule found on CT. Results: Fifty-five patients were scanned with stationary digital chest tomosynthesis. The median nodule size was 6 mm (IQR =4–13 mm). Twenty nodules (37%) were greater than 8 mm. The radiation entrance dose for s-DCT was 0.6 mGy. A significant difference in identification of nodules using s-DCT was seen for nodules <8 vs. ≥8 mm in size (57.7% vs. 90.9%, CI: −0.375, −0.024; P<0.001). Inter-reader agreement was fair, and better for nodules ≥8 mm [0.278 (SE =0.043)]. Conclusions: With system and carbon nanotube array optimization, we hypothesize the detection rate for nodules will improve. Additional study is needed to evaluate its use in target and tool co-localization and target biopsy.
Die Frage nach der Bedeutung des Wortes »Gott«
Creators: name: Spaemann, Robert
Publisher: name: Internationale katholische Zeitschrift Communio
Year: 2022

description: Internationale katholische Zeitschrift Communio, Bd. 1 Nr. 1 (1972): Internationale katholische Zeitschrift Communio, Band 1, Heft 1
Beyond Einstein's General Relativity
Creators: name: Lobo, Francisco S. N.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Modern astrophysical and cosmological models are plagued with two severe theoretical difficulties, namely, the dark energy and the dark matter problems. Relative to the former, high-precision observational data have confirmed with startling evidence that the Universe is undergoing a phase of accelerated expansion. This phase, one of the most important and challenging current problems in cosmology, represents a new imbalance in the governing gravitational equations. Several candidates, responsible for this expansion, have been proposed in the literature, in particular, dark energy models and modified gravity, amongst others. Outstanding questions are related to the nature of this so-called "dark energy" that is driving the acceleration of the universe, and whether it is due to the vacuum energy or a dynamical field. On the other hand, the late-time cosmic acceleration may be due to modifications of General Relativity, which introduce new degrees of freedom to the gravitational sector itself. We analyze some of the modified theories of gravity that address these intriguing and exciting problems facing modern physics, and explore the foundations of gravitation theory, essential for the construction of modified theories of gravity.
description: 16 pages. Proceedings based on a plenary talk delivered at the Spanish Relativity Meeting 2014 (ERE-2014). V2: references added, typos corrected. V3: reference added
Kirchliches Parlament oder synodale Diakonie?
Creators: name: Corecco, Eugenio
Publisher: name: Internationale katholische Zeitschrift Communio
Year: 2022

description: Internationale katholische Zeitschrift Communio, Bd. 1 Nr. 1 (1972): Internationale katholische Zeitschrift Communio, Band 1, Heft 1
Hydrodynamics from scalar black branes
Creators: name: Roychowdhury, Dibakar
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, using the Gauge/gravity duality techniques, we explore the hydrodynamic regime of a very special class of strongly coupled QFTs that come up with an emerging UV length scale in the presence of a negative hyperscaling violating exponent. The dual gravitational counterpart for these QFTs consists of scalar dressed black brane solutions of exactly integrable Einstein-scalar gravity model with Domain Wall (DW) asymptotics. In the first part of our analysis we compute the $ R $-charge diffusion for the boundary theory and find that (unlike the case for the pure $ AdS_{4} $ black branes) it scales quite non trivially with the temperature. In the second part of our analysis, we compute the $ η/s $ ratio both in the non extremal as well as in the extremal limit of these special class of gauge theories and it turns out to be eqaul to $ 1/4π$ in both the cases. These results therefore suggest that the quantum critical systems in the presence of (negative) hyperscaling violation at UV, might fall under a separate universality class as compared to those conventional quantum critical systems with the usual $ AdS_4 $ duals.
description: 19 pages, minor changes, Version to appear in JHEP
Tracing snowlines and C/O ratio in a planet-hosting disk: ALMA molecular line observations towards the HD169142 disk
Creators: name: Booth, Alice S.
name: Law, Charles J.
name: Temmink, Milou
name: Leemker, Margot
name: Macias, Enrique
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The composition of a forming planet is set by the material it accretes from its parent protoplanetary disk. Therefore, it is crucial to map the chemical make-up of the gas in disks to understand the chemical environment of planet formation. This paper presents molecular line observations taken with the Atacama Large Millimeter/submillimeter Array of the planet-hosting disk around the young star HD 169142. We detect N2H+, CH3OH, [CI], DCN, CS, C34S, 13CS, H2CS, H2CO, HC3N and c-C3H2 in this system for the first time. Combining these data with the recent detection of SO and previously published DCO+ data, we estimate the location of H2O and CO snowlines and investigate radial variations in the gas phase C/O ratio. We find that the HD 169142 disk has a relatively low N2H+ flux compared to the disks around Herbig stars HD 163296 and MWC 480 indicating less CO freeze-out and place the CO snowline beyond the millimetre disk at ~150 au. The detection of CH3OH from the inner disk is consistent with the H2O snowline being located at the edge of the central dust cavity at ~20 au. The radially varying CS/SO ratio across the proposed H2O snowline location is consistent with this interpretation. Additionally, the detection of CH3OH in such a warm disk adds to the growing evidence supporting the inheritance of complex ices in disks from the earlier, colder stages of star formation. Finally, we propose that the giant HD 169142 b located at 37 au is forming between the CO2 and H2O snowlines where the local elemental make of the gas is expected to have C/O=1.0.
description: Accepted A&A 13th August 2023
Elastic scattering and total reaction cross sections of $^{6}$Li studied with a microscopic continuum discretized coupled channels model
Creators: name: Chen, Wendi
name: Pang, D. Y.
name: Guo, Hairui
name: Tao, Ye
name: Sun, Weili
name: Ying, Yangjun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present a systematic study of $^{6}$Li elastic scattering and total reaction cross sections at incident energies around the Coulomb barrier within the continuum discretized coupled-channels (CDCC) framework, where $^{6}$Li is treated in an $α$+$d$ two-body model. Collisions with $^{27}$Al, $^{64}$Zn, $^{138}$Ba and $^{208}$Pa are analyzed. The microscopic optical potentials (MOP) based on Skyrme nucleon-nucleon interaction for $α$ and $d$ are adopted in CDCC calculations and satisfactory agreement with the experimental data is obtained without any adjustment on MOPs. For comparison, the $α$ and $d$ global phenomenological optical potentials (GOP) are also used in CDCC analysis and a reduction no less than 50$\%$ on the surface imaginary part of deuteron GOP is required for describing the data. In all cases, the $^6$Li breakup effect is significant and provides repulsive correction to the folding model potential. The reduction on the surface imaginary part of GOP of deuteron reveals a strong suppression of the reaction probability of deuteron as a component of $^{6}$Li as compared with that of a free deuteron. A further investigation is made by taking the $d$ breakup process into account equivalently within the dynamic polarization potential approach and it shows that $d$ behaves like a tightly bound nucleus in $^{6}$Li induced reactions.
description: 12 pages, 16 figures
Stability of a trapped dipolar quantum gas
Creators: name: Baillie, D.
name: Bisset, R. N.
name: Blakie, P. B.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We calculate the stability diagram for a trapped normal Fermi or Bose gas with dipole-dipole interactions. Our study characterizes the roles of trap geometry and temperature on the stability using Hartree-Fock theory. We find that exchange appreciably reduces stability, and that, for bosons, the double instability feature in oblate trapping geometries predicted previously is still predicted by the Hartree-Fock theory. Our results are relevant to current experiments with polar molecules and will be useful in developing strategies to obtain a polar molecule Bose-Einstein condensate or degenerate Fermi gas.
description: 7 pages, 4 figures
Strongly correlated flat-band systems: The route from Heisenberg spins to Hubbard electrons
Creators: name: Derzhko, Oleg
name: Richter, Johannes
name: Maksymenko, Mykola
Publisher: name: arXiv
Year: 2015
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: In this review we recapitulate the basic features of the flat-band spin systems and briefly summarize earlier studies in the field. Main emphasis is made on recent developments which include results for both spin and electron flat-band models. In particular, for flat-band spin systems we highlight field-driven phase transitions for frustrated quantum Heisenberg antiferromagnets at low temperatures, chiral flat-band states, as well as the effect of a slight dispersion of a previously strictly flat band due to nonideal lattice geometry. For electronic systems, we discuss the universal low-temperature behavior of several flat-band Hubbard models, the emergence of ground-state ferromagnetism in the square-lattice Tasaki-Hubbard model and the related Pauli-correlated percolation problem, as well as the dispersion-driven ground-state ferromagnetism in flat-band Hubbard systems. Closely related studies and possible experimental realizations of the flat-band physics are also described briefly.
description: 72 pages, 20 figures, 157 references; accepted for publication in International Journal of Modern Physics B
Asymmetries from the interference between Cabibbo-favored and doubly-Cabibbo-suppressed D decays
Creators: name: Gao, Dao-Neng
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: A phenomenological analysis of $D\to Kπ$ and $D_s^+\to K K $decays including both Cabibbo-favored and doubly-Cabibbo-suppressed modes have been presented by employing the present experimental data. SU(3) symmetry breaking effects from the decay constants and form factors have been taken into account in the analysis. Three asymmetries, $R(D^0)$, $R(D^+)$, and $R(D_s^+)$, which are generated through interference between Cabbibo-favored and doubly- Cabibbo-suppressed decays, are estimated. Theoretical results agree well with the current measurements.
description: 9 pages, 1 figure. Some discussions on asymmetries added in Section 3. To appear in Phys. Rev. D
Evaluation of carbon nanotube x-ray source array for stationary head computed tomography
Creators: name: Inscoe, C.R.
name: Spronk, D.
name: Lee, Y.Z.
name: Lu, J.
name: Luo, Y.
name: Zhou, O.
Publisher: name: John Wiley and Sons Ltd
Year: 2021

description: Purpose: Stationary computed tomography (s-CT) conceptually offers several advantages over existing rotating gantry-based CT. Over the last 40 yr, s-CT has been investigated using different technological approaches. We are developing a s-CT system specifically for head/brain imaging using carbon nanotube (CNT)-based field emission x-ray source array technology. The noncircular geometry requires different assessment approaches as compared to circular geometries. The purpose of the present study is to investigate whether the CNT source array meets the requirements for stationary head CT (s-HCT). Methods: Multiple prototype CNT x-ray source arrays were manufactured based on the system requirements obtained from simulation. Source characterization was performed using a benchtop setup consisting of an x-ray source array with 45 distributed focal spots, each operating at 120 kVp, and an electronic control system (ECS) for high speed control of the x-ray output from individual focal spots. Due to the forward-angled geometry of the linear anode, the projected focal spot shape is expected to vary at wide angle views. A pinhole method was implemented to determine the effective focal spot size (FSS) in the imaging plane at a range of angular viewpoints with a flat panel detector. The output spectrum and half value layer (HVL) were also evaluated for a range of viewing angles to characterize the beam quality across the fan-beam. Dosimetry was performed on a simulated scan to evaluate total exposure. Results: The prototype CNT x-ray source array demonstrated adequate specifications for a s-HCT imaging machine. The source array was operated at 120 kVp with long-term stability over a full year of regular laboratory use. Multiple cathode current measurements were used to confirm submicrosecond accuracy with regards to exposure time and subsequently dose control. All 45 focal spots were measured with an average value of 1.26 (±0.04) mm × 1.21 (±0.03) mm (equivalent to IEC 1,0). The x-ray spectrum was found to be appropriately filtered based on sources used in existing rotary CT systems. A stable and reliable output of 0.04 mAs per emitter and a resulting dose of 0.015 mGy per projection were observed over several months of rigorous phantom imaging. Dose per projection was regulated by the ECS and measured with ±0.5% tolerance. Conclusions: The CNT x-ray source array was found to meet the requirements for the proposed stationary head CT scanner, with regard to FSS, beam quality, and dose precision. The remaining challenges are related to the overall system design of a nonrotating CT scanner with distributed sources. The next phase of the project will incorporate multiple CNT source arrays with multirow detectors in a proof-of-concept study and analysis of a fully functional s-HCT system.
Fundamental scaling relationships revealed in the optical light curves of tidal disruption events
Creators: name: Mummery, Andrew
name: van Velzen, Sjoert
name: Nathan, Edward
name: Ingram, Adam
name: Hammerstein, Erica
name: Fraser-Taliente, Ludovic
name: Balbus, Steven
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present fundamental scaling relationships between properties of the optical/UV light curves of tidal disruption events (TDEs) and the mass of the black hole that disrupted the star. We have uncovered these relations from the late-time emission of TDEs. Using a sample of 63 optically-selected TDEs, the latest catalog to date, we observed flattening of the early-time emission into a near-constant late-time plateau for at least two-thirds of our sources. Compared to other properties of the TDE lightcurves (e.g., peak luminosity or decay rate) the plateau luminosity shows the tightest correlation with the total mass of host galaxy ($p$-value of $2 \times 10^{-6}$, with a residual scatter of 0.3 dex). Physically this plateau stems from the presence of an accretion flow. We demonstrate theoretically and numerically that the amplitude of this plateau emission is strongly correlated with black hole mass. By simulating a large population of TDEs, we determine a plateau luminosity-black hole mass scaling relationship well described by $ \log_{10} \left(M_{\bullet}/M_{\odot} \right) = 1.50 \log_{10} \left( L_{\rm plat}/10^{43} {\rm erg \, s^{-1}} \right) + 9.0 $. The observed plateau luminosities of TDEs and black hole masses in our large sample are in excellent agreement with this simulation. Using the black hole mass predicted from the observed TDE plateau luminosity, we reproduce the well-known scaling relations between black hole mass and galaxy velocity dispersion. The large black hole masses of 10 of the TDEs in our sample allow us to provide constraints on their black hole spins, favouring rapidly rotating black holes. We add 49 (34) black hole masses to the galaxy mass (velocity dispersion) scaling relationships, updating and extending these correlations into the low black hole mass regime.
description: Version 2: Data and analysis scripts now available at https://github.com/sjoertvv/manyTDE. 25 pages + appendices, 20 figures. Accepted version in MNRAS
Point-of-Care Tomosynthesis Imaging of the Wrist
Creators: name: Nissman, D.
name: Billingsley, A.J.
name: Puett, C.
name: Inscoe, C.R.
name: Lee, Y.
name: Lu, J.
name: Zhou, O.
Publisher: name: Oxford University Press
Year: 2021

description: Introduction: Musculoskeletal injury to extremities is a common issue for both stateside and deployed military personnel, as well as the general public. Superposition of anatomy can make diagnosis difficult using standard clinical techniques. There is a need for increased diagnostic accuracy at the point-of-care for military personnel in both training and operational environments, as well as assessment during follow-up treatment to optimize care and expedite return to service. Orthopedic tomosynthesis is rapidly emerging as an alternative to digital radiography (DR), exhibiting an increase in sensitivity for some clinical tasks, including diagnosis and follow-up of fracture and arthritis. Commercially available digital tomosynthesis systems are large complex devices. A compact device for extremity tomosynthesis (TomoE) was previously demonstrated using carbon nanotube X-ray source array technology. The purpose of this study was to prepare and evaluate the prototype device for an Institutional Review Board-approved patient wrist imaging study and provide initial patient imaging results. Materials and Methods: A benchtop device was constructed using a carbon nanotube X-ray source array and a flat panel digital detector. Twenty-one X-ray projection images of cadaveric specimens and human subjects were acquired at incident angles from -20 to +20 degrees in various clinical orientations, with entrance dose calibrated to commercial digital tomosynthesis wrist scans. The projection images were processed with an iterative reconstruction algorithm in 1 mm slices. Reconstruction slice images were evaluated by a radiologist for feature conspicuity and diagnostic accuracy. Results: The TomoE image quality was found to provide more diagnostic information than DR, with reconstruction slices exhibiting delineation of joint space, visual conspicuity of trabecular bone, bone erosions, fractures, and clear depiction of normal anatomical features. The scan time was 15 seconds and the skin entrance dose was verified to be 0.2 mGy. Conclusions: The TomoE device image quality has been evaluated using cadaveric specimens. Dose was calibrated for a patient imaging study. Initial patient images depict a high level of anatomical detail and an increase in diagnostic value compared to DR.
Probing the faint end Luminosity Function of Lyman Alpha Emitters at 3
Creators: name: Thai, Tran Thi
name: Tuan-Anh, Pham
name: Pello, Roser
name: Goovaerts, Ilias
name: Richard, Johan
name: Claeyssens, Adélaïde
name: Mahler, Guillaume
name: Lagattuta, David J.
name: de la Vieuville, Geoffroy
name: Salvador-Solé, Eduard
name: Garel, Thibault
name: Bauer, Franz E.
name: Jeanneau, Alexandre
name: Clément, Benjamin
name: Matthee, Jorryt
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a study of the galaxy Lyman-alpha luminosity function (LF) using a sample of 17 lensing clusters observed by the MUSE/VLT. Magnification from strong gravitational lensing by clusters of galaxies and MUSE apabilities allow us to blindly detect LAEs without any photometric pre-selection, reaching the faint luminosity regime. 600 lensed LAEs were selected behind these clusters in the redshift range 2.9<$z$< 6.7, covering four orders of magnitude in magnification-corrected Lyman-alpha luminosity (39.042 are consistent with those obtained from blank field observations. In the faint luminosity regime, the density of sources is well described by a steep slope, $α\sim-2$ for the global redshift range. Up to log(L)$\sim$41, the steepening of the faint end slope with redshift, suggested by the earlier work of DLV19 is observed, but the uncertainties remain large. A significant flattening is observed towards the faintest end, for the highest redshift bins (log$L$<41). Using face values, the steep slope at the faint-end causes the SFRD to dramatically increase with redshift, implying that LAEs could play a major role in the process of cosmic reionization. The flattening observed towards the faint end for the highest redshift bins still needs further investigation. This turnover is similar to the one observed for the UV LF at $z\geq6$ in lensing clusters, with the same conclusions regarding the reliability of current results (e.g.arXiv:1803.09747(N); arXiv:2205.11526(N)).
description: 20 pages, 15 figures, 6 tables. Accepted for publication in A\&A
Der sakramentale Charakter des Priesteramtes
Creators: name: Medina Estévez, Jorge
Publisher: name: Internationale katholische Zeitschrift Communio
Year: 2022

description: Internationale katholische Zeitschrift Communio, Bd. 1 Nr. 4 (1972): Internationale katholische Zeitschrift Communio, Band 1, Heft 4
Shell-model study of quadrupole collectivity in light tin isotopes
Creators: name: Coraggio, L.
name: Covello, A.
name: Gargano, A.
name: Itaco, N.
name: Kuo, T. T. S.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: A realistic shell-model study is performed for neutron-deficient tin isotopes up to mass A=108. All shell-model ingredients, namely two-body matrix elements, single-particle energies, and effective charges for electric quadrupole transition operators, have been calculated by way of the many-body perturbation theory, starting from a low-momentum interaction derived from the high-precision CD-Bonn free nucleon-nucleon potential. The focus has been put on the enhanced quadrupole collectivity of these nuclei, which is testified by the observed large B(E2;0+ -> 2+)s. Our results evidence the crucial role played by the Z=50 cross-shell excitations that need to be taken into account explicitly to obtain a satisfactory theoretical description of light tin isotopes. We find also that a relevant contribution comes from the calculated neutron effective charges, whose magnitudes exceed the standard empirical values. An original double-step procedure has been introduced to reduce effectively the model space in order to overcome the computational problem.
description: 6 pages, 6 figures, 2 tables
USING OF THE SUPERCOMPUTER CALCULATIONS FOR STUDY OF SOLAR FLARE MECHANISM VIA CORONAL MHD SIMULATION
Creators: name: Borisenko, А.V.
name: Podgorny, I.M.
name: Podgorny, A.I.
Publisher: name: Кольский научный центр Российской академии наук
Year: 2019

description: Numerical magnetohydrodynamic (MHD) simulation above the active region in the real scale of time, necessary to study the solar flare mechanism at the present stage, requires a significant increase in the calculation speed, which is achieved by parallelizing the calculations using a supercomputer. For this purpose, hardware and software for a supercomputer based on CUDA NVIDIA technology with a TESLA M2050 graphics card have been adjust. An example of parallelization using CUDA technology for the test problem of solving the Poisson equation showed an acceleration of the calculation by 20-100 times. The parallelization of the program for solving MHD equations using CUDA technology was carried out. However, attempts to execute a parallelized complex program forsolving MHD equations on an assembled supercomputer showed the need to work on dividing parallelized subroutines into smaller ones. This work has now been completed, but errors often occur when transferring values to the memory of the graphics card. For the correct execution of a parallelized program, it is necessary to introduce additional control of data transfer into it. Currently, such work is being carried out. A parallelization of the program for solving MHD equations in the Open MP system was carried out, which on a computer with an 8-core Intel Xeon 3.1Ghz processor with 16 threads accelerated the calculation by 50-70 times. The first results MHD simulation in the real scale of time above the active region of AO 10365 using parallelized in the system OpenMP program showed the formation of current sheets in the solar corona, in whose magnetic field the flare energy is accumulated.
Precise Discussion of Time-Reversal Asymmetries in B-meson decays
Creators: name: Morozumi, Takuya
name: Okane, Hideaki
name: Umeeda, Hiroyuki
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: BaBar collaboration announced that they observed time reversal (T) asymmetry through $B$ meson system. In the experiment, time dependencies of two distinctive processes, $B_- \rightarrow \bar{B^0}$ and $\bar{B^0}\rightarrow B_-$($-$ expresses CP value) are compared with each other. In our study, we examine event number difference of these two processes. In contrast to the BaBar asymmetry, the asymmetry of events number includes the overall normalization difference for rates. Time dependence of the asymmetry is more general and it includes terms absent in one used by BaBar collaboration. Both of the BaBar asymmetry and ours are naively thought to be T-odd since two processes compared are related with flipping time direction. We investigate the time reversal transformation property of our asymmetry. Using our notation, one can see that the asymmetry is not precisely a T-odd quantity, taking into account indirect CP and CPT violation of K meson systems. The effect of $ε_K$ is extracted and gives rise to $\mathcal{O}(10^{-3})$ contribution. The introduced parameters are invariant under rephasing of quarks so that the coefficients of our asymmetry are expressed as phase convention independent quantities. Some combinations of the asymmetry enable us to extract parameters for wrong sign decays of $B_d$ meson, CPT violation, etc. We also study the reason why the T-even terms are allowed to contribute to the asymmetry, and find that several conditions are needed for the asymmetry to be a T-odd quantity.
description: 29pages, 5 figures. In version3, the title is changed. The difference between the event number asymmetry and the asymmetry measured by BaBar experiment is clarified
On the three-dimensional relation between the coronal dimming, erupting filament and CME. Case study of the 28 October 2021 X1.0 event
Creators: name: Chikunova, Galina
name: Podladchikova, Tatiana
name: Dissauer, Karin
name: Veronig, Astrid M.
name: Dumbović, Mateja
name: Temmer, Manuela
name: Dickson, Ewan C. M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We investigate the relation between the spatiotemporal evolution of the dimming region and the dominant direction of the filament eruption and CME propagation for the 28 October 2021 X1.0 flare/CME event observed from multiple viewpoints by Solar Orbiter, STEREO-A, SDO, and SOHO. We propose a method to estimate the dominant dimming direction by tracking its area evolution and emphasize its accurate estimation by calculating the surface area of a sphere for each pixel. To determine the early flux rope propagation direction, we perform 3D reconstruction of the CME via graduated cylindrical shell modeling (GCS) and tie-pointing of the filament. The dimming initially expands radially and later shifts southeast. The orthogonal projections of the reconstructed height evolution of the erupting filament onto the solar surface are located in the sector of the dominant dimming growth, while the orthogonal projections of the inner part of GCS reconstruction align with the total dimming area. The filament reaches a maximum speed of $\approx$250 km/s at a height of about $\approx$180 Mm. The direction of its motion is strongly inclined from the radial (64$^\circ$ to the East, 32$^\circ$ to the South). The 50$^\circ$ difference in the 3D direction between the CME and the filament leg closely corresponds to the CME half-width determined from reconstruction, suggesting a potential relation of the reconstructed filament to the associated leg of the CME body. Our findings highlight that the dominant propagation of the dimming growth reflects the direction of the erupting magnetic structure (filament) low in the solar atmosphere, though the filament evolution is not related directly to the direction of the global CME expansion. The overall dimming morphology closely resembles the inner part of the CME reconstruction, validating the use of dimming observations to obtain insight into the CME direction.
description: 15 pages, 18 figures, accepted to Astronomy & Astrophysics
The role of stationary intraoral tomosynthesis in reducing proximal overlap in bitewing radiography
Creators: name: Lu, J.
name: Mol, A.
name: Mauriello, S.M.
name: Zhou, O.
name: Inscoe, C.R.
name: Broome, A.M.
name: Moss, K.
name: Platin, E.
Publisher: name: British Institute of Radiology
Year: 2020

description: objectives: This study examined the utility of stationary intraoral tomosynthesis (s-IOT) in opening proximal contacts in bitewing radiography. Methods: 11 DENTSPLY Rinn Dental X-ray Teaching and Training Replica mannequins (Model #546002, Elgin, Ill) were imaged with a prototype s-IOT device (Surround Medical Systems, Morrisville, NC) and standard bitewing (SBW) technique. Premolar and molar bite-wings were acquired with each system. Image receptor holders were used to position receptors and aid in the alignment of the position indicating devices. An expert operator (having more than 5 years of experience in intraoral radiography) acquired the images with the s-IOT prototype and standard intraoral X-ray devices. Images were assessed to analyze percentage overlap of the proximal surfaces using the tools available in ImageJ (NIH, Bethesda Maryland). Results: 253-paired surfaces were included in the analysis. The difference in overlap was statistically significant with standard bitewing (SBW) images resulting in a median overlap of 13%, a minimum of 0%, a maximum of 100% and an interquartile range of 40%. s-IOT resulted in a median overlap of 1%, a minimum of 0%, a maximum of 37% and an interquartile range of 0%. The s-IOT prototype substantially reduced proximal surface overlap compared to conventional bitewing radiography. conclusions: The use of s-IOT reduced proximal contact overlap compared to standard bitewing radiography for an experienced radiographer. Stationary intraoral tomosynthesis may be a potential alternative to SBW radiography, reducing the number of retakes due to closed contacts.
THE PHYSICAL MECHANISM OF THE SOLAR FLARE, STUDIED ON THE BASIS OF THE RESULTS OF OBSERVATIONS AND MHD SIMULATION
Creators: name: Podgorny, I.M.
name: Podgorny, А.I.
Publisher: name: Кольский научный центр Российской академии наук
Year: 2019

description: According to numerous indications obtained from observations primordial energy release during solar flares takes place in the solar corona above theactive regions. Emission in the lower layers of the solar corona, as well as processes in interplanetary space and in the Earth’s magnetosphere are the consequence of the primordial flare process in the solar corona. The flare is explained by the release of energy accumulated in the magnetic field of the current sheet formed in the corona. An electrodynamical model of a solar flare is proposed, which explains its main observational manifestations, in particular, the appearance of X-ray emission on the surface of the Sun. The first results of MHD simulation in the real scale of time show the appearance of current sheets in the corona above the active region, which confirms the proposed solar flare mechanism.
3D coupled tearing-thermal evolution in solar current sheets
Creators: name: Sen, Samrat
name: Jenkins, Jack
name: Keppens, Rony
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Combined tearing-thermal evolution plays an important role in the disruption of current sheets, and formation of cool condensations within the solar atmosphere. However, this has received limited attention to date. We numerically explore a combined tearing and thermal instability that causes the break up of an idealized current sheet in the solar atmosphere. The thermal component leads to the formation of localized, cool condensations within an otherwise 3D reconnecting magnetic topology. We construct a 3D resistive magnetohydrodynamic simulation of a force-free current sheet under solar atmospheric conditions that incorporate the non-adiabatic influence of background heating, optically thin radiative energy loss, and magnetic field aligned thermal conduction with the open source code MPI-AMRVAC. Multiple levels of adaptive mesh refinement reveal the self-consistent development of finer-scale condensation structures within the evolving system. The instability in the current sheet is triggered by magnetic field perturbations concentrated around the current sheet plane, and subsequent tearing modes develop. This in turn drives thermal runaway associated with the thermal instability of the system. We find subsequent, localized cool plasma condensations that form under the prevailing low plasma-$β$ conditions, and demonstrate that the density and temperature of these condensed structures are similar to more quiescent coronal condensations. Synthetic counterparts at Extreme-UltraViolet (EUV) and optical wavelengths show the formation of plasmoids (in EUV), and coronal condensations similar to prominences and coronal rain blobs in the vicinity of the reconnecting sheet. Our simulations imply that 3D reconnection in solar current sheets may well present an almost unavoidable multi-thermal aspect, that forms during their coupled tearing-thermal evolution.
description: Accepted for publication in Astronomy and Astrophysics journal