cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Natural width of the superconducting transition in epitaxial TiN films
Creators: name: Baeva, E. M.
name: Kolbatova, A. I.
name: Titova, N. A.
name: Saha, S.
name: Boltasseva, A.
name: Bogdanov, S.
name: Shalaev, V. M.
name: Semenov, A. V.
name: Goltsman, G. N.
name: Khrapai, V. S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigate the effect of various fluctuation mechanisms on the DC resistance in superconducting devices based on epitaxial titanium nitride (TiN) films. The samples we studied show a relatively steep resistive transition (RT), with a transition width $ΔT/T_\mathrm{c} \sim 0.002-0.025$, depending on the film thickness (20 nm, 9 nm, and 5 nm) and device dimensions. This value is significantly broader than expected due to conventional superconducting fluctuations ($ΔT/T_\mathrm{c} \ll 10^{-3}$). The shape and width of the RT can be perfectly described by the well-known effective medium theory, which allows us to understand the origin of the inhomogeneity in the superconducting properties of TiN films. We propose that this inhomogeneity can have both dynamic and static origins. The dynamic mechanism is associated with spontaneous fluctuations in electron temperature (T-fluctuations), while the static mechanism is due to a random spatial distribution of surface magnetic disorder (MD). Our analysis has revealed clear correlations between the transition width and material parameters as well as device size for both proposed mechanisms. While T-fluctuations may contribute significantly to the observed transition width, our findings suggest that the dominant contribution comes from the MD mechanism. Our results provide new insights into the microscopic origin of broadening of the superconducting transition and inhomogeneity in thin superconducting films.
description: as published
The Irradiation Instability of Protoplanetary Disks
Creators: name: Wu, Yanqin
name: Lithwick, Yoram
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The temperature in most parts of a protoplanetary disk is determined by irradiation from the central star. Numerical experiments of Watanabe \& Lin (2008) suggested that such disks, also called `passive disks', suffer from a thermal instability. Here, we use analytical and numerical tools to elucidate the nature of this instability. We find that it is related to the flaring of the optical surface, the layer at which starlight is intercepted by the disk. Whenever a disk annulus is perturbed thermally and acquires a larger scale height, disk flaring becomes steeper in the inner part, and flatter in the outer part. Starlight now shines more overhead for the inner part and so can penetrate into deeper layers; conversely, it is absorbed more shallowly in the outer part. These geometric changes allow the annulus to intercept more starlight, and the perturbation grows. We call this the irradiation instability. It requires only ingredients that are known to exist in realistic disks, and operates best in parts that are both optically thick and geometrically thin (inside 30AU, but can extend to further reaches when, e.g., dust settling is considered). An unstable disk develops travelling thermal waves that reach order-unity in amplitude. In thermal radiation, such a disk should appear as a series of bright rings interleaved with dark shadowed gaps, while in scattered light it resembles a moving staircase. Depending on the gas and dust responses, this instability could lead to a wide range of consequences, such as {\w ALMA rings and gaps,} dust traps, vertical circulation, vortices and turbulence.
description: accepted to ApJ; added 1 figure, 1 appendix, clarified the instability criterion
An oak is an oak, or not? Understanding and dealing with confusion and disagreement in biological classification
Creators: name: Cuypers, Vincent
name: Reydon, Thomas A. C.
Publisher: name: Dordrecht [u.a.] : Springer Science + Business Media B.V
Year: 2023
Subjects: subject: Classification
subject: Oaks
subject: Pluralism
subject: Policymaking
subject: Taxonomy
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie
subject: Dewey Decimal Classification::100 | Philosophie

description: Human interaction with the living world, in science and beyond, always involves classification. While it has been a long-standing scientific goal to produce a single all-purpose taxonomy of life to cater for this need, classificatory practice is often subject to confusion and disagreement, and many philosophers have advocated forms of classificatory pluralism. This entails that multiple classifications should be allowed to coexist, and that whichever classification is best, is context-dependent. In this paper, we discuss some practical consequences of classificatory pluralism, in particular with regard to how one is supposed to find the best classification for a given context. We do so by means of a case study concerning oaks, in particular the pedunculate oak (Quercus robur L.) and the sessile oak (Quercus petraea (Matt.) Liebl.), two important putative species that present several classificatory challenges; and by applying one recent philosophical framework conceptualizing classification, the so-called Grounded Functionality Account (GFA) of (natural) kinds. We show how the GFA elucidates several issues related to oak classification and gives directions to optimize classificatory practices, and discuss some implications for scientific taxonomy.
Modularity of $\operatorname{PGL}_2(\mathbb{F}_p)$-representations over totally real fields
Creators: name: Allen, Patrick B.
name: Khare, Chandrashekhar B.
name: Thorne, Jack A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11F41, 11F80

description: We study an analogue of Serre's modularity conjecture for projective representations $\overlineρ: \operatorname{Gal}(\overline{K} / K) \rightarrow \operatorname{PGL}_2(k)$, where $K$ is a totally real number field. We prove new cases of this conjecture when $k = \mathbb{F}_5$ by using the automorphy lifting theorems over CM fields established in previous work of the authors.
description: 11 pages. Refereed version
Spatially Hyperbolic Gravitating Sources in $Λ$-Dominated Era
Creators: name: Yousaf, Z.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: This study focuses on the impact of the cosmological constant on hyperbolically symmetric matter configurations in static background. We extend the work of Herrera \cite{herrera2021hyperbolically} and describe the influences of such repulsive character on a few realistic features of hyperbolical anisotropic fluids. After describing Einstein-$Λ$ equations of motion, we elaborated the corresponding mass function along with its conservation laws. In our study, besides observing negative energy density, we notice the formation of Minkowskian core as matter content is compelled itself not to follow inward motion near the axis of symmetry. Three families of solution are found in $Λ$-dominated epoch. First is calculated by keeping zero value to Weyl scalar, while the second solution maintains zero complexity in the subsequent changes of the hyperbolical compact object. However, the last model encompasses stiff fluid within the self-gravitating system. Such type of theoretical setup suggests its direct link to study a few particular quantum scenarios where negative behavior of energy density is noticed at $Λ$ dominated regime.
description: 14 pages, 4 figures, version accepted for publications in Universe
Integrating Frequency Translational Invariance in TDNNs and Frequency Positional Information in 2D ResNets to Enhance Speaker Verification
Creators: name: Thienpondt, Jenthe
name: Desplanques, Brecht
name: Demuynck, Kris
Publisher: name: arXiv
Year: 2021
Subjects: subject: Audio and Speech Processing (eess.AS)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper describes the IDLab submission for the text-independent task of the Short-duration Speaker Verification Challenge 2021 (SdSVC-21). This speaker verification competition focuses on short duration test recordings and cross-lingual trials, along with the constraint of limited availability of in-domain DeepMine Farsi training data. Currently, both Time Delay Neural Networks (TDNNs) and ResNets achieve state-of-the-art results in speaker verification. These architectures are structurally very different and the construction of hybrid networks looks a promising way forward. We introduce a 2D convolutional stem in a strong ECAPA-TDNN baseline to transfer some of the strong characteristics of a ResNet based model to this hybrid CNN-TDNN architecture. Similarly, we incorporate absolute frequency positional encodings in an SE-ResNet34 architecture. These learnable feature map biases along the frequency axis offer this architecture a straightforward way to exploit frequency positional information. We also propose a frequency-wise variant of Squeeze-Excitation (SE) which better preserves frequency-specific information when rescaling the feature maps. Both modified architectures significantly outperform their corresponding baseline on the SdSVC-21 evaluation data and the original VoxCeleb1 test set. A four system fusion containing the two improved architectures achieved a third place in the final SdSVC-21 Task 2 ranking.
description: proceedings of INTERSPEECH 2021
Observational consequences of the hypothesized helium rich stellar population in Omega Centauri
Creators: name: Newsham, G.
name: Terndrup, D. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In response to the proposed high helium content stars as an explanation for the double main sequence observed in Omega Centauri, we investigated the consequences of such stars elsewhere on the color-magnitude diagram. We concentrated on the horizontal branch where the effects of high helium are expected to show themselves more clearly. In the process, we developed a procedure for comparing the mass loss suffered by differing stellar populations in a physically motivated manner. High helium stars in the numbers proposed seem absent from the horizontal branch of Omega Centauri unless their mass loss history is very different from that of the majority metal-poor stars. It is possible to generate a double main sequence with existing Omega Centauri stars via accretion of helium rich pollution consistent with the latest AGB ejecta theoretical yields, and such polluted stars are consistent with the observed HB morphology of Omega Centauri. Polluted models are consistent with observed merging of the main sequences as opposed to our models of helium rich stars. Using the (B-R)/(B+V+R) statistic, we find that the high helium bMS stars require an age difference compared to the rMS stars that is too great, whereas the pollution scenario stars have no such conflict for inferred Omega Centauri mass losses.
description: 37 pages, 10 figures, accepted for publication in ApJ
Piecewise rotations: limit set for the non -bijective maps
Creators: name: Bédaride, Nicolas
name: Bertazzon, Jean françois
name: Kaboré, Idrissa
Publisher: name: arXiv
Year: 2022
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We consider non-bijective piecewise rotations of the plane. These maps belong to a family introduced in previous papers by Boshernitzan and Goetz. We derive in this paper some upper bounds to the size of the limit set. This improves results of \cite{Bosh.Goet.03}.
description: 24 pages
Singular Oscillatory Integrals on R^n
Creators: name: Papadimitrakis, M.
name: Parissis, I. R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 46B20, 26D05

description: Let Pd,n denote the space of all real polynomials of degree at most d on R^n. We prove a new estimate for the logarithmic measure of the sublevel set of a polynomial P in Pd,1. Using this estimate, we prove a sharp estimate for a singular oscillatory integral on R^n.
description: final version, 10 pages, small typos corrected, one reference added. To appear in Math. Z
Dissipative processes at the acoustic horizon
Creators: name: Chiofalo, Maria Luisa
name: Grasso, Dario
name: Mannarelli, Massimo
name: Trabucco, Silvia
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A transonic fluid flow generates an acoustic hole that is the hydrodynamic analogue of a gravitational black hole. Acoustic holes emit a detectable thermal radiation of phonons at a characteristic Hawking temperature. The crucial concept is that the spontaneous phonon emission at the horizon produces an irreversible heat increase at the expenses of the bulk fluid kinetic energy. We show that such process can be described in terms of \textit{effective} shear and bulk viscosities that are defined close to the horizon. We analyze this quantum friction process by resorting to a general kinetic theory approach as well as by the specific description of phonon emission as a tunneling process. The celebrated Kovtun, Son and Starinets (KSS) universal lower bound $η/s = 1 / 4 π$ of the shear viscosity coefficient to entropy density ratio, readily follows, and is extended to the longitudinal bulk viscosity at the horizon. We come to the same saturation of the KSS bound after considering the shear viscosity arising from a perturbation of the background metric at the acoustic horizon providing a -- in principle testable -- realization of the so called black hole \textit{membrane paradigm}.
description: 9 pages, 1 figure. Extended discussion on viscosities. Added references. Results unchanged, almost matches the published version on NJP
Donaldson theory on non-Kählerian surfaces and class $VII$ surfaces with $b_2=1$
Creators: name: Teleman, Andrei
Publisher: name: arXiv
Year: 2007
Subjects: subject: Differential Geometry (math.DG)
subject: Algebraic Geometry (math.AG)
subject: Complex Variables (math.CV)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 53C55; 53C07; 32Q57; 32G13

description: We prove that any class $VII$ surface with $b_2=1$ has curves. This implies the "Global Spherical Shell conjecture" in the case $b_2=1$: Any minimal class $VII$ surface with $b_2=1$ admits a global spherical shell, hence it is isomorphic to one of the surfaces in the known list. The main idea of the proof is to show that a certain moduli space of PU(2)-instantons on a surface $X$ with no curves (if such a surface existed) would contain a closed Riemann surface $Y$ whose general points correspond to non-filtrable holomorphic bundles on $X$. Then we pass from a family of bundles on $X$ parameterized by $Y$ to a family of bundles on $Y$ parameterized by $X$, and we use the algebraicity of $Y$ to obtain a contradiction. The proof uses essentially techniques from Donaldson theory: compactness theorems for moduli spaces of PU(2)-instantons and the Kobayashi-Hitchin correspondence on surfaces.
description: LaTeX, 29 pages
Spectroscopic Confirmation of the Sixth Globular Cluster in the Fornax Dwarf Spheroidal Galaxy
Creators: name: Pace, Andrew B.
name: Walker, Matthew G.
name: Koposov, Sergey E.
name: Caldwell, Nelson
name: Mateo, Mario
name: Olszewski, Edward W.
name: Bailey, John I.
name: Wang, Mei-Yu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Fornax dwarf spheroidal galaxy has an anomalous number of globular clusters, five, for its stellar mass. There is a longstanding debate about a potential sixth globular cluster (Fornax~6) that has recently been `rediscovered' in DECam imaging. We present new Magellan/M2FS spectroscopy of the Fornax~6 cluster and Fornax dSph. Combined with literature data we identify $\sim15-17$ members of the Fornax~6 cluster that this overdensity is indeed a star cluster and associated with the Fornax dSph. The cluster is significantly more metal-rich (mean metallicity of $\overline{\rm [Fe/H]}=-0.71\pm0.05$) than the other five Fornax globular clusters ($-2.5
description: 17 pages, 9 figures. Accepted to ApJ. Data catalogs included. Comments welcome
Senior citizen housing implementing a continuum of care environment
Creators: name: Marek, Danna S.
Publisher: name: University of British Columbia
Year: 2010

description: In the last twenty five years the health of individuals worldwide has changed. Life expectancy has substantially increased and the proportion of older citizens is growing constantly. This growing population of elderly people will dominate the housing market in the coming years. An increased demand for housing and health care services for the elderly calls not only for much greater supply than we have ever experienced, but also for new approaches, one of which is based on the graduation of care. Provincial and local governments are looking for innovative options and design solutions which could meet the needs and expectations of a new wave of seniors at the end of this century. It is the intention of this thesis to identify and define what are the underlying principles in planning housing and services for the contemporary elderly. The Thesis has been developed as a research cycle based on a three-phase methodology of analysis-synthesis-evaluation. Analysis commences with comprehensive research into existing facilities and introduces the notion of multi-level care of the elderly. It investigates the real meaning of the quality environment within the elderly facility in terms of a continuum of his/her lifestyle. Synthesis defines the phenomenon of the continuum of care environment in the full scale facility program for the proposed Continuum of Care Complex (CCC) in West Point Grey in Vancouver, B.C. Evaluation investigates the feasibility of the program implementation on a test site. A basic premise of the thesis is that a multi-level care facility is a viable way of achieving an environment, which may fulfill a comprehensive array of needs of the elderly. It should include housing alternatives for the elderly, both in terms of tenure and supportive services, but above all should provide a specific ambiance equal to a home-like environment. The thesis has been structured as a hypothetical model of a programming system based on the principle of the continuum of care. This model includes four major functional components of the proposed complex: residential, long-term care, community services and outdoor activity spaces that blending together create a quality environment. This model has been developed in the real situation of the Point Grey Community on the principle of an active interaction. Subsequently this model has been tested on a selected site in terms of identification of opportunities and constraints which may affect successful program implementation. The thesis concludes that a hypothetical model of the Continuum of Care Complex can be successfully implemented on the selected test site of the Point Grey Community. "Continuum of Care" environment for the elderly developed in the model may satisfy a broad range of needs for the elderly: physical, physiological and sociopsychological.
Multi-scalar signature of self-interacting dark matter in the NMSSM and beyond
Creators: name: Li, Jinmian
name: Pei, Junle
name: Zhang, Cong
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: This work studies the self-interacting dark matter (SIDM) scenario in the general NMSSM and beyond, where the dark matter is a Majorana fermion and the force mediator is a scalar boson. An improved analytical expression for the dark matter (DM) self-interacting cross section which takes into account the Born level effects is proposed. Due to the large couplings and light mediator in SIDM scenario, the DM/mediator will go through multiple branchings if they are produced with high energy. Based on the Monte Carlo simulation of the showers in the DM sector, we obtain the multiplicities and the spectra of the DM/mediator from the Higgsino production and decay at the LHC for our benchmark points.
description: 27 pages, 8 figures
VLBI detection of an Infrared-Faint Radio Source
Creators: name: Norris, Ray P.
name: Tingay, Steven
name: Phillips, Chris
name: Middelberg, Enno
name: Deller, Adam
name: Appleton, Philip N.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Infrared-Faint Radio Sources represent a new and unexpected class of object which is bright at radio wavelengths but unusually faint at infrared wavelengths. If, like most mJy radio sources, they were either conventional active or star-forming galaxies in the local Universe, we would expect them to be detectable at infrared wavelengths, and so their non-detection by the Spitzer Space Telescope is surprising. Here we report the detection of one of these sources using Very Long Baseline Interferometry, from which we conclude that the sources are driven by Active Galactic Nuclei. We suggest that these sources are either normal radio-loud quasars at high redshift or abnormally obscured radio galaxies.
description: accepted by MNRAS
Genuine vs. naïve symmetric monoidal G-categories
Creators: name: Lenz, Tobias
Publisher: name: arXiv
Year: 2022
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 55P91 (Primary) 55P48, 19D23, 55U35 (Secondary)

description: We prove that through the eyes of equivariant weak equivalences the genuine symmetric monoidal $G$-categories of Guillou and May [Algebr. Geom. Topol. 17 (2017), no. 6, 3259-3339; arXiv:1809.03017] are equivalent to just ordinary symmetric monoidal categories with $G$-action. Along the way, we give an operadic model of global infinite loop spaces and provide an equivalence between the equivariant category theory of genuine symmetric monoidal $G$-categories and the $G$-parsummable categories studied by Schwede [J. Topol. 15 (2022), no. 3, 1325-1454; arXiv:1912.08872] and the author [New York J. Math. 29 (2023), 635-686; arXiv:2009.07004].
description: Final version, based on feedback by referees: improved exposition, added subsection 2.4, generalized construction in Section 5, various minor corrections. 80 pages
Higgs boson tagging with the Lund jet plane
Creators: name: Khosa, Charanjit K.
name: Marzani, Simone
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We construct a procedure to separate boosted Higgs bosons decaying into hadrons, from the background due to strong interactions. We employ the Lund jet plane to obtain a theoretically well-motivated representation of the jets of interest and we use the resulting images as the input to a convolutional neural network classifier. In particular, we consider two different decay modes of the Higgs boson, namely into a pair of bottom quarks or into light jets, against the respective backgrounds. For each case, we consider both a moderate- and high- boost scenario. The performance of the tagger is compared to what is achieved using a traditional single-variable analysis which exploits a QCD inspired color-singlet tagger, namely the jet color ring observable.
description: 10 pages, 7 figures, published version
Practice made Practical. Reducing the OTHER of non-text
Creators: name: Vials Moore, Adam
name: Evans, Jenny
name: Kotarski, Rachael
name: Mudd, Taylor
Publisher: name: Zenodo
Year: 2021
Subjects: discoverability
practice research
non-text outputs
persistent identifiers
metadata

description: The academy has become increasingly expert at the creation and description of STEM textual articles and data along with building platforms for their discovery, access and inquiry. However, for disciplines where outputs are not typically textual in nature, such as architecture, practice research, etc. there are still many challenges in the way these outputs and related resources are described. We propose that working with existing expert communities, such as repositories that have built taxonomies to address these outputs, we can build the vocabularies of the wider global infrastructure - the persistent identifiers and metadata that underpin scholarly information networks - so that the work types are richer, more descriptive, allowing better discoverability, and bringing a future where all aspects of research are equally valued.
New numerical framework for the generalized Baumgarte-Shapiro-Shibata-Nakamura formulation: The vacuum case for spherical symmetry
Creators: name: Alcoforado, M. A.
name: Aranha, R. F.
name: Barreto, W. O.
name: de Oliveira, H. P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Here we report a developed high performance and simplified version of the code denominated RIO, which can be easily extended, for the generalized BSSN formulation. We implement a code which is regular at the center of symmetry, without use a special procedure for regularization, as usual. We get exponential convergence for constraints. The numerical algorithm is based on the Galerkin-Collocation method developed successfully for diverse physical scenarios by the Numerical Relativity Group at UERJ. For the sake of clarity in presentation, we consider here the most simple case to display the most salient features of the procedure. Thus, we focus on the definite tests of the new numerical framework. The timing and performance of the code show that we can reach a better accuracy close to the machine precision, for the Hamiltonian and momentum constraints. RIO will be an open source code; currently is under continuous development to consider more general and realistic problems.
description: 10 pages, 5 figures. To appear in PRD
Asymptotic localization in multicomponent mass conserving coagulation equations
Creators: name: Ferreira, Marina A.
name: Lukkarinen, Jani
name: Nota, Alessia
name: Velázquez, Juan J. L.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 45K05, 35Q

description: In this paper we prove that the time dependent solutions of a large class of Smoluchowski coagulation equations for multicomponent systems concentrate along a particular direction of the space of cluster compositions for long times. The direction of concentration is determined by the initial distribution of clusters. These results allow to prove the uniqueness and global stability of the self-similar profile with finite mass in the case of coagulation kernels which are not identically constant, but are constant along any direction of the space of cluster compositions.
description: 33 pages
Muon-fluorine entangled states in molecular magnets
Creators: name: Lancaster, T.
name: Blundell, S. J.
name: Baker, P. J.
name: Brooks, M. L.
name: Hayes, W.
name: Pratt, F. L.
name: Manson, J. L.
name: Conner, M. M.
name: Schlueter, J. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The information accessible from a muon-spin relaxation experiment is often limited since we lack knowledge of the precise muon stopping site. We demonstrate here the possibility of localizing a spin polarized muon in a known stopping state in a molecular material containing fluorine. The muon-spin precession that results from the entangled nature of the muon-spin and surrounding nuclear spins is sensitive to the nature of the stopping site and we use this property to identify three classes of site. We are also able to describe the extent to which the muon distorts its surroundings.
description: 4 pages, 3 figures
Revisiting He-like X-ray Emission Line Plasma Diagnostics
Creators: name: Porter, R. L.
name: Ferland, G. J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A complete model of helium-like line and continuum emission has been incorporated into the plasma simulation code Cloudy. All elements between He and Zn are treated, any number of levels can be considered, and radiative and collisional processes are included. This includes photoionization from all levels, line transfer including continuum pumping and destruction by background opacities, scattering, and collisional processes. The model is calculated self-consistently along with the ionization and thermal structure of the surrounding nebula. The result is a complete line and continuum spectrum of the plasma. Here we focus on the ions of the He I sequence and reconsider the standard helium-like X-ray diagnostics. We first consider semi-analytical predictions and compare these with previous work in the low-density, optically-thin limit. We then perform numerical calculations of helium-like X-ray emission (such as is observed in some regions of Seyferts) and predict line ratios as a function of ionizing flux, hydrogen density, and column density. In particular, we demonstrate that, in photoionized plasmas, the $R$-ratio, a density indicator in a collisional plasma, depends on the ionization fraction and is strongly affected by optical depth for large column densities. We also introduce the notion that the $R$-ratio is a measure of the incident continuum at UV wavelengths. The $G$-ratio, which is temperature-sensitive in a collisional plasma, is also discussed, and shown to be strongly affected by continuum pumping and optical depth as well. These distinguish a photoionized plasma from the more commonly studied collisional case.
description: 28 pages, 7 figures, accepted to ApJ
The new $(g-2)_μ$ result and the $μν$SSM
Creators: name: Heinemeyer, Sven
name: Kpatcha, Essodjolo
name: Lara, Iñaki
name: López-Fogliani, Daniel E.
name: Muñoz, Carlos
name: Nagata, Natsumi
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The $μν$SSM is a highly predictive alternative model to the MSSM. In particular, the electroweak sector of the model can explain the longstanding discrepancy between the experimental result for the anomalous magnetic moment of the muon, $(g-2)_μ$, and its Standard Model prediction, while being in agreement with all other theoretical and experimental constraints. The recently published MUON G-2 result is within $0.8\,σ$ in agreement with the older BNL result on $(g-2)_μ$. The combined result was announced as $a_μ^{\rm exp} = (11659206.1 \pm 4.1) \times 10^{-10}$, yielding a new deviation from the Standard Model prediction of $Δa_μ= (25.1 \pm 5.9) \times 10^{-10}$, corresponding to $4.2\,σ$. Using this improved bound we update the analysis in the $μν$SSM as presented in Ref. [1] and set new limits on the allowed parameters space of the electroweak sector of the model. We conclude that significant regions of the model can explain the new $(g-2)_μ$ data.
description: Version published in EPJC. Discussion expanded, references added. 34 pages, 10 figures, 1 table. Follow-up of arXiv:1912.04163
Labelled partitions in action: recombination, selection, mutation, and more
Creators: name: Alberti, Frederic
Publisher: name: arXiv
Year: 2022
Subjects: subject: Probability (math.PR)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Mathematics
subject: FOS: Biological sciences
subject: 60J25, 92D15

description: In this paper, we consider the evolution of an (infinitely large) population under recombination and additional evolutionary forces, modelled by a measure-valued ordinary differential equation. We provide a stochastic representation for the solution of this model via duality to a new labelled partitioning process with Markovian labels. In the special case of single-crossover, this leads to a recursive solution formula. This extends (and unifies) previous results on the selection-recombination equation. As a concrete example, we consider the selection-mutation-recombination equation.
How many hyenas in North America? A quantitative perspective
Creators: name: Pérez-Claros, Juan A.
name: Coca-Ortega, Carlos
name: Werdelin, Lars
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Biophysics
subject: Biochemistry
subject: Space Science
subject: 29999 Physical Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: Molecular Biology
subject: Physiology
subject: FOS: Biological sciences
subject: Biotechnology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: Science Policy
subject: 110309 Infectious Diseases
subject: FOS: Health sciences

description: How many hyenas in North America? A quantitative perspective
Darboux Transformation of the Green Function for the Dirac Equation with the Generalized Potential
Creators: name: Pozdeeva, Ekaterina
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the Darboux transformation of the Green functions of the regular boundary problem of the one-dimensional stationary Dirac equation. We obtained the Green functions of the transformed Dirac equation with the initial regular boundary conditions. We also construct the formula for the unabridged trace of the difference of the transformed and the initial Green functions of the regular boundary problem of the one-dimensional stationary Dirac equation. We illustrate our findings by the consideration of the Darboux transformation for the Green function of the free particle Dirac equation on an interval.
description: 14 pages,zip. file: Latex, 1 figure. Typos corrected, the figure replaced
Experimental investigation of the tire wear process using camera-assisted observation assessed by numerical modeling
Creators: name: Licher, J.
name: Schmerwitz, F.
name: Soleimani, M.
name: Junker, P.
Publisher: name: Amsterdam [u.a.] : Elsevier Science
Year: 2023
Subjects: subject: Abrasion
subject: Degraded layer relaxation
subject: Experimental investigation
subject: Finite element modeling
subject: Image analysis
subject: Multi-physics
subject: Rubber tread wear
subject: Wear model
subject: Dewey Decimal Classification::600 | Technik::660 | Technische Chemie

description: This paper presents a novel experimental method to study the abrasion mechanism of car tires. It is based on the detection of microscopic movements associated with material damage (cracking) on the rubber tread. This is referred to as degrading layer relaxation. It correlates with the wear rate and, interestingly, the direction of the pattern's movement is opposite to the lateral forces during cornering. To measure and analyze the microscopic movements, a new camera-based method with feature point matching using video stabilization was developed. Besides extensive experimental investigation, the formation and propagation of microcracks are investigated using a simplified numerical model in which a phase field approach coupled with a viscoelastic constitutive behavior is implemented in a finite element framework.
Eclipsing light curves for accretion flows around a rotating black hole and atmospheric effects of the companion star
Creators: name: Takahashi, Rohta
name: Watarai, Ken-Ya
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We calculate eclipsing light curves for accretion flows around a rotating black hole taking into account the atmospheric effects of the companion star. In the cases of no atmospheric effects, the light curves contain the information of the black hole spin because most of the X-ray photons around 1 keV usually come from the blueshifted part of the accretion flow near the black hole shadow, and the size and the position of the black hole shadow depend on the spin. In these cases, when most of the emission comes from the vicinity of the event horizon, the light curves become asymmetric at ingress and egress. We next investigate the atmospheric absorption and scattering effects of the companion stars. By using the solar-type atmospheric model, we have taken into account the atmospheric effects of the companion star, such as the photoionization by HI and HeI. We found that the eclipsing light curves observed at 1 keV possibly contain the information of the black hole spin. However, in our atmospheric model, the effects of the atmosphere are much larger than the effects of the black hole spin. Therefore, even in the case that the light curves contain the information of the black hole spin, it may be difficult to extract the information of the black hole spin if we do not have the realistic atmospheric profiles, such as the temperature, and the number densities for several elements. Even in such cases, the light-curve asymmetries due to the rotation of the accretion disc exist. Only when we have the reliable atmospheric model, in principle, the information of the strong-gravity regions, such as the black hole spin, can be obtained from the eclipsing light curves.
description: Takahashi R., Watarai K., 2007, MNRAS, 374, 1515
Switching between Magnetic Bloch and Néel Domain Walls with Anisotropy Modulations
Creators: name: Franke, Kévin J. A.
name: Ophus, Colin
name: Schmid, Andreas K.
name: Marrows, Christopher H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: It has been shown previously that the presence of a Dzyaloshinskii-Moriya interaction in perpendicularly magnetized thin films stabilizes Néel type domain walls. We demonstrate, using micromagnetic simulations and analytical modeling, that the presence of a uniaxial in-plane magnetic anisotropy can also lead to the formation of Néel walls in the absence of a Dzyaloshinskii-Moriya interaction. It is possible to abruptly switch between Bloch and Néel walls via a small modulation of both the in-plane, but also the perpendicular magnetic anisotropy. This opens up a route towards electric field control of the domain wall type with small applied voltages through electric field controlled anisotropies.
A molecular wind blows out of the Kuiper belt
Creators: name: Kral, Quentin
name: Pringle, J. E.
name: Guilbert-Lepoutre, Aurélie
name: Matrà, Luca
name: Moses, Julianne I.
name: Lellouch, Emmanuel
name: Wyatt, Mark C.
name: Biver, Nicolas
name: Bockelée-Morvan, Dominique
name: Bonsor, Amy
name: Petit, Franck Le
name: Gladstone, G. Randall
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Gas has been detected in many exoplanetary systems ($>$10 Myr), thought to be released in the destruction of volatile-rich planetesimals orbiting in exo-Kuiper belts. In this letter, we aim to explore whether gas is also expected in the Kuiper belt (KB) in our Solar System. To quantify the gas release in our Solar System, we use models for gas release that have been applied to extrasolar planetary systems, as well as a physical model that accounts for gas released due to the progressive internal warming of large planetesimals. We find that only bodies larger than about 4 km can still contain CO ice after 4.6 Gyr of evolution. This finding may provide a clue as to why Jupiter-family comets, thought to originate in the Kuiper belt, are deficient in CO compared to Oort-clouds comets. We predict that gas is still produced in the KB right now at a rate of $2 \times 10^{-8}$ M$_\oplus$/Myr for CO and orders of magnitude more when the Sun was younger. Once released, the gas is quickly pushed out by the Solar wind. Therefore, we predict a gas wind in our Solar System starting at the KB location and extending far beyond with regards to the heliosphere with a current total CO mass of $\sim 2 \times 10^{-12}$ M$_\oplus$. We also predict the existence of a slightly more massive atomic gas wind made of carbon and oxygen (neutral and ionized) with a mass of $\sim 10^{-11}$ M$_\oplus$. We predict that gas is currently present in our Solar System beyond the Kuiper belt and that although it cannot be detected with current instrumentation, it could be observed in the future with an in situ mission using an instrument similar to Alice on New Horizons with larger detectors. Our model of gas release due to slow heating may also work for exoplanetary systems and provide the first real physical mechanism for the gas observations.
description: accepted for publication as a Letter to the editor in A&A; abstract shortened; 15 pages, 5 figures, 4 tables
Lenticels are sites of initiation of microcracking and russeting in ‘Apple’ mango
Creators: name: Athoo, Thomas O.
name: Winkler, Andreas
name: Owino, Willis O.
name: Knoche, Moritz
Publisher: name: San Francisco, California, US : PLOS
Year: 2023
Subjects: subject: Animals
subject: Birds
subject: Cognition
subject: Fruit
subject: Malus
subject: Mangifera
subject: Waxes
subject: rain
subject: wax
subject: apple
subject: cultivar
subject: cuticle
subject: fluorescence microscopy
subject: fluorescent lighting
subject: Dewey Decimal Classification::500 | Naturwissenschaften
subject: Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit

description: The mango cultivar ‘Apple’ is an important fruitcrop in Kenya, but it is highly susceptible to russeting. The objective was to establish whether lenticels predispose cv. ‘Apple’ mango to russeting. Fruit mass and surface area increased in a sigmoidal pattern with time. The frequency of lenticels per unit surface area decreased during development. The number of lenticels per fruit was constant. Lenticels were most frequent in the apex region and least common in the cheek and nak (ventral) regions. The cheek region also had lenticels with the largest core areas, whereas the lenticel core areas in the apex region were significantly smaller. Microscopy revealed stomata became covered over with wax deposits at 33 days after full bloom (DAFB). By 78 DAFB, periderm had formed beneath the pore. At 110 and 161 DAFB, cracks had developed and the periderm had extended tangentially and radially. The presence of lenticels increased the strain released upon excision of an epidermal segment, further strain releases occurred subsequently upon isolation of the cuticle and on extraction of the cuticular waxes. The number of lenticels per unit surface area was negatively correlated with the fruit surface area (r2 = 0.62 **), but not affected by fruit size. Mango cv. ‘Apple’ had fewer, larger lenticels and more russet, compared with ‘Ngowe’, ‘Kitovu’ or ‘Tommy Atkins’ mango. In cv. ‘Apple’, the lowest lenticel frequency, the largest lenticels and the most russeting occurred at a growing site at the highest altitude, with the highest rainfall and the lowest temperature. Moisture exposure of the fruit surface resulted in enlarged lenticels and more microcracking of the cuticle. Our results establish that russeting in ‘Apple’ mango is initiated at lenticels and is exacerbated if lenticels are exposed to moisture.
Velocities from Cross-Correlation: A Guide for Self-Improvement
Creators: name: Prieto, Carlos Allende
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The measurement of Doppler velocity shifts in spectra is a ubiquitous theme in astronomy, usually handled by computing the cross-correlation of the signals, and finding the location of its maximum. This paper addresses the problem of the determination of wavelength or velocity shifts among multiple spectra of the same, or very similar, objects. We implement the classical cross-correlation method and experiment with several simple models to determine the location of the maximum of the cross-correlation function. We propose a new technique, 'self-improvement', to refine the derived solutions by requiring that the relative velocity for any given pair of spectra is consistent with all others. By exploiting all available information, spectroscopic surveys involving large numbers of similar objects may improve their precision significantly. As an example, we simulate the analysis of a survey of G-type stars with the SDSS instrumentation. Applying 'self-improvement' refines relative radial velocities by more than 50% at low signal-to-noise ratio. The concept is equally applicable to the problem of combining a series of spectroscopic observations of the same object, each with a different Doppler velocity or instrument-related offset, into a single spectrum with an enhanced signal-to-noise ratio.
description: 7 pages, 3 figures, uses emulateapj.cls; to appear in the Astronomical Journal; see http://hebe.as.utexas.edu/stools/ to obtain the companion software
The enigmatic nucleus of the marine dinoflagellateProrocentrum cordatum
Creators: name: Kalvelage, Jana
name: Wöhlbrand, Lars
name: Schoon, Robin-Alexander
name: Zink, Fiona-Marine
name: Correll, Christina
name: Senkler, Jennifer
name: Eubel, Holger
name: Hoppenrath, Mona
name: Rhiel, Erhard
name: Braun, Hans-Peter
name: Winklhofer, Michael
name: Klingl, Andreas
name: Rabus, Ralf
Publisher: name: Washington, DC : American Society for Microbiology
Year: 2023
Subjects: subject: chromosomes
subject: dinoflagellate
subject: dinokaryon
subject: FIB/SEM
subject: genomics
subject: nuclear functions
subject: nucleus
subject: Prorocentrum cordatum
subject: proteomics
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: The marine, bloom-forming dinoflagellateProrocentrum cordatum CCMP 1329 (formerly P. minimum) has a genome atypical of eukaryotes, with a large size of ∼4.15 Gbp, organized in plentiful, highly condensed chromosomes and packed in a dinoflagellate-specificnucleus (dinokaryon). Here, we apply microscopic and proteogenomic approaches to obtain new insights into this enigmatic nucleus of axenic P. cordatum. High-resolution focused ion beam/scanning electron microscopy analysis of the flattenednucleus revealed highest density of nuclear pores in the vicinity of the nucleolus, a total of 62 tightly packed chromosomes (∼0.4-6.7 μm3), and interaction of several chromosomes with the nucleolus and other nuclear structures. A specificprocedure for enriching intact nuclei was developed to enable proteomic analyses of soluble and membrane protein-enriched fractions. These were analyzed with geLC and shotgun approaches employing ion-trap and timsTOF (trapped-ion-mobility-spectrometry time-of-flight)mass spectrometers, respectively. This allowed identificationof 4,052 proteins (39% of unknown function), out of which 418 were predicted to serve specificnuclear functions; additional 531 proteins of unknown function could be allocated to the nucleus. Compaction of DNA despite very low histone abundance could be accomplished by highly abundant major basic nuclear proteins (HCc2-like). Several nuclear processes including DNA replication/repair and RNA processing/splicing can be fairly well explained on the proteogenomic level. By contrast, transcription and composition of the nuclear pore complex remain largely elusive. One may speculate that the large group of potential nuclear proteins with currently unknown functions may serve yet to be explored functions in nuclear processes differingfrom those of typical eukaryotic cells.