cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Large Scale Structure of f(R) Gravity
Creators: name: Song, Yong-Seon
name: Hu, Wayne
name: Sawicki, Ignacy
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the evolution of linear cosmological perturbations in f(R) models of accelerated expansion in the physical frame where the gravitational dynamics are fourth order and the matter is minimally coupled. These models predict a rich and testable set of linear phenomena. For each expansion history, fixed empirically by cosmological distance measures, there exists two branches of f(R) solutions that are parameterized by B propto d^2 f/dR^2. For B<0, which include most of the models previously considered, there is a short-timescale instability at high curvature that spoils agreement with high redshift cosmological observables. For the stable B>0 branch, f(R) models can reduce the large-angle CMB anisotropy, alter the shape of the linear matter power spectrum, and qualitatively change the correlations between the CMB and galaxy surveys. All of these phenomena are accessible with current and future data and provide stringent tests of general relativity on cosmological scales.
description: 10 pages, 6 figures, minor typo fixes reflects version accepted by PRD
Critical and Tricritical Points for the Massless 2d Gross-Neveu Model Beyond Large N
Creators: name: Kneur, Jean-Loic
name: Pinto, Marcus Benghi
name: Ramos, Rudnei O.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Other Condensed Matter (cond-mat.other)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Using optimized perturbation theory, we evaluate the effective potential for the massless two dimensional Gross-Neveu model at finite temperature and density containing corrections beyond the leading large-N contribution. For large-N, our results exactly reproduce the well known 1/N leading order results for the critical temperature, chemical potential and tricritical points. For finite N, our critical values are smaller than the ones predicted by the large-N approximation and seem to observe Landau's theorem for phase transitions in one space dimension. New analytical results are presented for the tricritical points that include 1/N corrections. The easiness with which the calculations and renormalization are carried out allied to the seemingly convergent optimized results displayed, in this particular application, show the robustness of this method and allows us to obtain neat analytical expressions for the critical as well as tricritical values beyond the results currently known.
description: 29 pages, 14 figures
Accurate and Efficient Simulations of Hamiltonian Mechanical Systems with Discontinuous Potentials
Creators: name: Tao, Molei
name: Jin, Shi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Dynamical Systems (math.DS)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: This article considers Hamiltonian mechanical systems with potential functions admitting jump discontinuities. The focus is on accurate and efficient numerical approximations of their solutions, which will be defined via the laws of reflection and refraction. Despite of the success of symplectic integrators for smooth mechanical systems, their construction for the discontinuous ones is nontrivial, and numerical convergence order can be impaired too. Several rather-usable numerical methods are proposed, including: a first-order symplectic integrator for general problems, a third-order symplectic integrator for problems with only one linear interface, arbitrarily high-order reversible integrators for general problems (no longer symplectic), and an adaptive time-stepping version of the previous high-order method. Interestingly, whether symplecticity leads to favorable long time performance is no longer clear due to discontinuity, as traditional Hamiltonian backward error analysis does not apply any more. Therefore, at this stage, our recommended default method is the last one. Various numerical evidence, on the order of convergence, long time performance, momentum map conservation, and consistency with the computationally-expensive penalty method, are supplied. A complex problem, namely the Sauteed Mushroom, is also proposed and numerically investigated, for which multiple bifurcations between trapped and ergodic dynamics are observed.
description: Questions and comments are welcome
[Rezension von: Preul, Reiner, So wahr mir Gott helfe!, Religion in der modernen Gesellschaft]
Creators: name: Hailer, Martin
name: Preul, Reiner
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 55 Nr. 1 (2006): Ökumenische Rundschau, Band 55, Heft 1
A note on the stability of Morris-Thorne wormholes
Creators: name: Kuhfittig, Peter K. F.
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Two critical issues in the study of Morris-Thorne wormholes concerns the stability of such structures, as well as their compatibility with quantum field theory. This note discusses an important subset characterized by zero tidal forces. It is shown that such wormholes (1) are in stable equilibrium using a criterion based on the Tolman-Oppenheimer-Volkoff (TOV) equation and (2) are not in direct conflict with quantum field theory.
description: 6 pages, no figures
Characterization of the Lovelock gravity by Bianchi derivative
Creators: name: Dadhich, Naresh
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We prove the theorem: The second order quasi-linear differential operator as a second rank divergence free tensor in the equation of motion for gravitation could always be derived from the trace of the Bianchi derivative of the fourth rank tensor, which is a homogeneous polynomial in curvatures. The existence of such a tensor for each term in the polynomial Lagrangian is a new characterization of the Lovelock gravity.
description: Agrees with the published version
Photon and Dilepton Production in Soft Wall AdS/QCD
Creators: name: Atmaja, A. Nata
name: Schalm, K.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the Soft-Wall-model of AdS/QCD to calculate photon production in strongly coupled Quark Gluon Plasma (sQGP). The IR cut-off only affects the low-frequency-component of the production rate. The full spectral function is determined numerically and shows remarkable similarity to computations of the photon production rate in AdS-duals of $\mathcal{N}=2$ theories with massive flavor. It is further support that Soft-Wall AdS-QCD correctly captures the IR physics of the chiral perturbation theory regime of QCD. We confirm this by relating the IR-effects of the massive flavor deformations to the AdS/QCD soft wall cut-off. The AdS/QCD spectral function is smooth, however, and unlike massive flavor models shows no spectral peaks.
description: 22 pages, 3 figs; v2: references added, clarifications made and minor corrections
Effects of charged Higgs bosons in the deep inelastic process ν_τ {\cal N} \to τ^- X and the possibility of detecting tau-neutrinos at cosmic neutrino detectors
Creators: name: Rosado, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the deep inelastic process $ν_τ + {\cal N} \to τ^{-} + X$ (with ${\cal N} \equiv (n+p)/2$ an isoscalar nucleon), in the context of the two Higgs doublet model type II (2HDM(II)). We discuss the contribution to the total cross section of diagrams, in which a charged Higgs boson is exchanged. We present results which show the strong dependence of such contribution on $\tanβ$ and $M_{H^{\pm}}$. We show that in the region $50 \leq \tanβ\leq 200$ and 90 GeV $\leq M_{H^{\pm}}\leq$ 600 GeV with the additional experimental constraint on the involved model parameters $M_{H^{\pm}} \geq 1.5 \times \tanβ$ GeV, the contribution of the charged Higgs boson exchange diagrams to the cross section of the charged current inclusive $ν_τ {\cal N}$ collision can become important. We obtain that this contribution for an inclusive dispersion generated through the collision of an ultrahigh energy tau-neutrino with $E_ν \approx 10^{20}$ eV on a target nucleon can be larger than the value of the contribution of the $W^{\pm}$ exchange diagrams, provided that $M_{H^{\pm}} \approx 300$ GeV and $\tanβ\approx 200$. Such enhancement and the induced variation on the mean inelasticity $^{CC}$ could lead to sizeable effects in the acceptance of cosmic tau-neutrino detectors at experiments such as HiRes, PAO, and the CRTNT, which are anchored to the ground, and at experiments such as EUSO and OWL, which are proposed to orbit around the Earth.
description: 18 pages, 2 figures, 8 tables
Absence of line fields and Mane's theorem for non-recurrent transcendental functions
Creators: name: Rempe, Lasse
name: van Strien, Sebastian
Publisher: name: arXiv
Year: 2008
Subjects: subject: Dynamical Systems (math.DS)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 37F10 (Primary), 30D05, 37D25, 27F15, 37F35 (Secondary)

description: Let f be a transcendental meromorphic function. Suppose that the finite part of the postsingular set of f is bounded, that f has no recurrent critical points or wandering domains, and that the degree of pre-poles of f is uniformly bounded. Then we show that f supports no invariant line fields on its Julia set. We prove this by generalizing two results about rational functions to the transcendental setting: a theorem of Mane about the branching of iterated preimages of disks, and a theorem of McMullen regarding absence of invariant line fields for "measurably transitive" functions. Both our theorems extend results previously obtained by Graczyk, Kotus and Swiatek.
description: 28 pages; V3. Proof of Theorem 7.4 corrected, as well as some other minor corrections
Workshop day 4: Demonstration of ACORNS software
Creators: name: Parker, Verdena
name: Ammon, Danny
name: Campbell, Amy
name: George-Moore, Melodie
name: Jackson, Silis
name: Martins, Jacalyn
name: Newbold, Lindsey
name: Spence, Justin
name: Parker, Otis
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: hup

description: Audio files VP-220710-04 through VP-220710-09: Demonstration of ACORNS (Acquisition of Restored Native Speech), language learning software developed by Dan Harvey (Professor of Computer Science at Southern Oregon University). Recorded at a workshop in Hoopa Valley. The participants identified here were present at most sessions during the workshop; additional people were also present, some of whom participate in the conversation.
Η απόδοση των αμοιβαίων κεφαλαίων στην ελληνική κεφαλαιαγορά
Creators: name: Φλωρόπουλος, Νικόλαος Ιορδάνης
Publisher: name: Aristotle University of Thessaloniki
Year: 2008
Subjects: Αμοιβαία κεφάλαια
Κεφαλαιαγορά
Απόδοση αμοιβαίων κεφαλαίων
Κίνδυνος αμοιβαίων κεφαλαίων
Συντελεστής συσχέτισης αμοιβαίων κεφαλαίων
Οικογένεις αμοιβαίων κεφαλαίων
Mutual funds
Capital market
Families
of mutual funds
Performance of mutual funds
Danger of mutual funds
Correlation between mutual funds

description: Σε αυτή τη διπλωματική εργασία μελετάται η απόδοση των αμοιβαίων κεφαλαίων και των οικογενειων αμοιβαιων κεφαλαίων στην ελληνική κεφαλαιαγορά τα έτη 2002-2007. Επίσης, μελετάται η συσχέτιση που υπάρχει ανάμεσα σε αμοιβαία κεφάλαια ιδιας ή διαφορετικής οικογένειας.
description: The performance of mutual funds and of the families of mutual funds is studied during the years 2002-2007. Also, the correlation that exists between mutual funds of the same or different families.
SDSS-IV MaNGA: the "G-dwarf problem" revisited
Creators: name: Greener, Michael J.
name: Merrifield, Michael
name: Aragón-Salamanca, Alfonso
name: Peterken, Thomas
name: Andrews, Brett
name: Lane, Richard R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The levels of heavy elements in stars are the product of enhancement by previous stellar generations, and the distribution of this metallicity among the population contains clues to the process by which a galaxy formed. Most famously, the "G-dwarf problem" highlighted the small number of low-metallicity G-dwarf stars in the Milky Way, which is inconsistent with the simplest picture of a galaxy formed from a "closed box" of gas. It can be resolved by treating the Galaxy as an open system that accretes gas throughout its life. This observation has classically only been made in the Milky Way, but the availability of high-quality spectral data from SDSS-IV MaNGA and the development of new analysis techniques mean that we can now make equivalent measurements for a large sample of spiral galaxies. Our analysis shows that high-mass spirals generically show a similar deficit of low-metallicity stars, implying that the Milky Way's history of gas accretion is common. By contrast, low-mass spirals show little sign of a G-dwarf problem, presenting the metallicity distribution that would be expected if such systems evolved as pretty much closed boxes. This distinction can be understood from the differing timescales for star formation in galaxies of differing masses.
description: 5 pages, 2 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society
Τα αίτια και ο μηχανισμός λειτουργίας της χειμαρρικής δράσης του Χ. Ρ. καταρράκτη του Ν. Αρτας
Creators: name: Λαναρά, Θεοδώρα Βασιλείου
Publisher: name: Aristotle University of Thessaloniki
Year: 2008
Subjects: Χειμαρρικό περιβάλλον (δυναμικό)
Λεκάνη απορροής
Χειμαρρικό ρεύμα
Παράγοντες χειμαρρικότητας
Καταρράκτης
Υδρονομικά έργα
Torrential environment
Basin
Torrent
Torrential factors
Katarraktis
Torrent control works

description: Στην εργασία μελετήθηκαν τα αίτια και ο μηχανισμός λειτουργίας της χειμαρρικής δράσης του χειμαρρικού ρεύματος "Καταρράκτη". Στην αρχή γίνεται μια περιγραφή της περιοχής και χαρτογραφική απεικόνιση του χειμαρρικού ρεύματος. Αναλύονται οι βασικοί παράγοντες χειμαρρικότητας (κλίμα, γεωλογικό υπόθεμα, ανάγλυφο και βλάστηση). Στη συνέχεια αναλύεται το χειμαρρικό περιβάλλον (δυναμικό) της περιοχής (χειμαρρικά φαινόμενα-εστίες παραγωγής φερτών υλικών και γίνεται υπολογισμός της μέγιστης υδατοπαροχής και στερεοπαροχής. Τέλος έγινε προσπάθεια ώστε να καταγραφούν τα τεχνικά και φυτοτεχνικά έργα (εκτελεσθέντα υδρονομικά έργα) στη λεκάνη απορροής του χειμαρρικού ρεύματος "Καταρράκτη". Μετά από επιτόπια μετάβαση στις θέσεις κατασκευής των έργων και την παράλληλη λήψη φωτογραφιών, έγινε αξιολόγηση του τρόπου λειτουργίας τους (είδος κατασκευασθέντος έργου, υλικά δόμησης, σημερινή κατάσταση, εκπλήρωση σκοπού κατασκευής)
description: In this paper the cause and the mechanism of torrential action of torrent "Katarraktis" is investigated. Firstly the area is described and mapping of torrent "Katarraktis". The basic torrential factors of the are analyzed (climate, geological support, relief and vegetation). In addition the torrential environment (potential) of the research area is investigated (torrential phenomena) and calculation of the maximum expectend rain off and sediment discharge of the research area torrent is determined. Finally there was an attempt of registration all the technical and planting works (torrent control works) constructed at the research area. Functionality controls of the constructios after visiting them and getting photographs (kind of constructed work, construction materials, present condition)
On the structure of giant HII regions and HII galaxies
Creators: name: Tenorio-Tagle, G.
name: Munoz-Tunon, C.
name: Perez, E.
name: Silich, S.
name: Telles, E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We review the structural properties of giant extragalactic HII regions and HII galaxies based on two dimensional hydrodynamic calculations, and propose an evolutionary sequence that accounts for their observed detailed structure. The model assumes a massive and young stellar cluster surrounded by a large collection of clouds. These are thus exposed to the most important star-formation feedback mechanisms: photoionization and the cluster wind. The models show how the two feedback mechanisms compete with each other in the disruption of clouds and lead to two different hydrodynamic solutions: The storage of clouds into a long lasting ragged shell that inhibits the expansion of the thermalized wind, and the steady filtering of the shocked wind gas through channels carved within the cloud stratum that results into the creation of large-scale superbubbles. Both solutions are here claimed to be concurrently at work in giant HII regions and HII galaxies, causing their detailed inner structure. A full description of the calculations can be found in The Astrophysical Journal 643, 186. Animated version of the models presented can be found at http://www.iaa.csic.es/\~{}eperez/ssc/ssc.html.
description: 4 pages, to be published in Proceedings IAU Symposium 237 "Triggered Star Formation in a Turbulent ISM", eds. B.G. Elmegreen & J. Palous
AutoGraph: Automated Graph Neural Network
Creators: name: Li, Yaoman
name: King, Irwin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: Graphs play an important role in many applications. Recently, Graph Neural Networks (GNNs) have achieved promising results in graph analysis tasks. Some state-of-the-art GNN models have been proposed, e.g., Graph Convolutional Networks (GCNs), Graph Attention Networks (GATs), etc. Despite these successes, most of the GNNs only have shallow structure. This causes the low expressive power of the GNNs. To fully utilize the power of the deep neural network, some deep GNNs have been proposed recently. However, the design of deep GNNs requires significant architecture engineering. In this work, we propose a method to automate the deep GNNs design. In our proposed method, we add a new type of skip connection to the GNNs search space to encourage feature reuse and alleviate the vanishing gradient problem. We also allow our evolutionary algorithm to increase the layers of GNNs during the evolution to generate deeper networks. We evaluate our method in the graph node classification task. The experiments show that the GNNs generated by our method can obtain state-of-the-art results in Cora, Citeseer, Pubmed and PPI datasets.
description: Accepted by ICONIP 2020
Soriculus Blyth 1854
Creators: name: Chen, Zhongzheng
name: Pei, Xiaoxin
name: Hu, Jiangxiao
name: Song, Wenyu
name: Khanal, Laxman
name: Li, Quan
name: Jiang, Xuelong
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Soricomorpha
Soricidae
Soriculus

description: Genus Soriculus Blyth, 1854
Type species: Soriculus nigrescens (Gray, 1842).
Remarks: Shrews in Soriculus are medium to large sized in the tribe Nectogalini, with W 7.7–20.7 g, HB 62–93 mm; and CIL 19.2–24.5 mm (Table 1). These shrews have a rather stout body and enlarged foreclaws. The dorsal pelage of the shrews varies in colour, from brown to almost black, ventral pelage slighter paler than the dorsum. The pinnae are small, but visible. The tail is about half the head and body length (TL/HB = 43–74%) and gently tapered; the tail is not sharply bicolored, and is similar in colour to the dorsal and ventral fur. The skull is robust and bony, and the coronoid process is spatulate. The dental formula of the genus is: I 3/2, C 1/0, P 2/1, M 3/3 (×2) = 30, following the tooth nomenclature of Hutterer (2005b). There are four upper unicuspids. M 3, the entoconid crest of M 1, and the labial cingulum of the lower molars are reduced. The teeth are lightly pigmented orange or reddish.
Comparisons: Soriculus can be distinguished from the other Nectogaline genera by the combination of its enlarged foreclaws, reduced M 3 and the entoconid crest of M 1, and a spatulate coronoid process. It can further be distinguished from Chodsigoa, Chimarrogale, and Nectogale by the four upper unicuspids (three in Chodsigoa, Chimarrogale, and Nectogale). The tail of Soriculus (TL/HB <75%) is relatively shorter than Chodsigoa and Episoriculus (TL/HB> 80%). The teeth of Soriculus are lightly pigmented which differ from the unpigmented teeth in Nectogale and Chimarrogale. The normal tail of Soriculus is noticeably different than the keeled tail with long stiff hairs in Neomys.
Distribution and habitat: The genus is restricted to the Himalayas and the southern Hengduan Mountains (specifically the Gaolingong Mountains) from Nepal to northern India, Bhutan, northern Myanmar, and western China (southern Tibet and western Yunnan). Its enlarged foreclaws, small ears, and short tail indicate a semi-fossorial lifestyle. It occurs in various montane forests, open rocky areas, and in the alpine zone above the timberline at elevations from 700 m to 4500 m a.s.l..
description: Published as part of Chen, Zhongzheng, Pei, Xiaoxin, Hu, Jiangxiao, Song, Wenyu, Khanal, Laxman, Li, Quan & Jiang, Xuelong, 2024, Multilocus phylogeny and morphological analyses illuminate overlooked diversity of Soriculus (Mammalia: Eulipotyphla: Soricidae), with descriptions of two new endemic species from the eastern Himalayas, pp. 534-548 in Zoological Journal of the Linnean Society 201 (2) on pages 539-541, DOI: 10.1093/zoolinnean/zlad131, http://zenodo.org/record/13219976
Διερεύνηση της γνώσης και χρήσης γραμματικών κανόνων στη γραφή των παιδιών του δημοτικού σχολείου
Creators: name: Δημοπούλου, Γεωργία Ναπολέοντος
Publisher: name: Aristotle University of Thessaloniki
Year: 2008
Subjects: Δημοτικό σχολείο
Ορθογραφία
Μορφοσύνταξη
θεματικό μόρφημα
Primary school
Spelling
Morpho-syntax
Stem-morpheme

description: Στην παρούσα έρευνα, η οποία πραγματοποιήθηκε κατά το σχολικό έτος 2006-2007, προσπαθήσαμε να διερευνήσουμε την αιτία των περισσότερων ορθογραφικών λαθών που κάνουν οι μαθητές/-τριες της Ε’ και ΣΤ’ τάξης του δημοτικού σχολείου στα θεματικά μορφήματα, καθώς και την ορθογραφική τους ικανότητα. Για το σκοπό αυτό έλαβαν μέρος στην έρευνα 138 παιδιά των παραπάνω τάξεων. Τους δόθηκαν τα εξής τεστ: α) τρία έργα μορφοσύνταξης και β) ένα έργο γραφής λέξεων μέσα σε προτάσεις. Τα αποτελέσματα έδειξαν ότι αιτία των περισσότερων ορθογραφικών λαθών αποτελεί η πολλαπλότητα των επιλογών που αντιστοιχούν σε ένα φώνημα. Παρατηρήθηκε αναπτυξιακή πορεία, η οποία όμως οφείλεται στην ικανότητα για μεγαλύτερη απομνημόνευση και όχι στη χρήση μορφοσυντακτικών στρατηγικών. Αποδείχθηκε, επίσης, ότι τα παιδιά κάνουν κυρίως χρήση της στρατηγικής της απομνημόνευσης και της επινοημένης γραφής. Ωστόσο, σημειώθηκε σημαντική συσχέτιση ανάμεσα στη χρήση μορφοσυντακτικών στρατηγικών και στην ικανότητα για ορθογραφημένη γραφή.
description: In the present study, wich took place during the school year 2006-2007, we have tried to investigate the cause of most of the mistakes pupils of the fifth and sixth grade of Primary school make in the case of stem-morphemes as well as their spelling abilities. For this purpose 138 pupils participated. They were given the following tasks: a) three morpho-syntactic tests and b) a writing word-filling cloze test, where the words were taken from their respective basic vocabulary of the language text-book. The results showed that the cause of most of the mistakes constitutes multiplicity of choices that correspond to a phoneme. The developmental course of the spelling competence of students of the 5th and 6th grade was confirmed, which is however due to the faculty for bigger memorization and not to the use of morpho-syntactic strategies. It was proved that the children make mainly use of the strategy of memorization and inventing spelling. Nevertheless, a significant correlation was noted between the use of the morpho-syntactic strategy and the capacity for orthographic writing.
Impact of stoichiometry and strain on Ge$_{1-x}$Sn$_{x}$ alloys from first principles calculations
Creators: name: O'Donnell, Conor
name: Sanchez-Soares, Alfonso
name: Broderick, Christopher A.
name: Greer, James C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We calculate the electronic structure of germanium-tin (Ge$_{1-x}$Sn$_{x}$) binary alloys for $0 \leq x \leq 1$ using density functional theory (DFT). Relaxed alloys with semiconducting or semimetallic behaviour as a function of Sn composition $x$ are identified, and the impact of epitaxial strain is included by constraining supercell lattice constants perpendicular to the [001] growth direction to the lattice constants of Ge, zinc telluride (ZnTe), or cadmium telluride (CdTe) substrates. It is found that application of 1% tensile strain reduces the Sn composition required to bring the (positive) direct band gap to zero by approximately 5% compared to a relaxed Ge$_{1-x}$Sn$_{x}$ alloy having the same gap at $Γ$. On the other hand, compressive strain has comparatively less impact on the alloy band gap at $Γ$. Using DFT calculated alloy lattice and elastic constants, the critical thickness for Ge$_{1-x}$Sn$_{x}$ thin films as a function of $x$ and substrate lattice constant is estimated, and validated against supercell DFT calculations. The analysis correctly predicts the Sn composition range at which it becomes energetically favourable for Ge$_{1-x}$Sn$_{x}$/Ge to become amorphous. The influence of stoichiometry and strain is examined in relation to reducing the magnitude of the inverted (``negative'') $Γ_{7}^{-}$-$Γ_{8}^{+}$ band gap, which is characteristic of semimetallic alloy electronic structure. Based on our findings, strategies for engineering the semimetal-to-semiconductor transition via strain and quantum confinement in Ge$_{1-x}$Sn$_{x}$ nanostructures are proposed.
description: 16 pages, 9 figures
The Auslander-Reiten translate on monomial quotient rings
Creators: name: Brun, Morten
name: Floystad, Gunnar
Publisher: name: arXiv
Year: 2008
Subjects: subject: Commutative Algebra (math.AC)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 13D99, 13F99

description: For a multidegree t in N^n, E.Miller has defined a category of positively t-determined modules over the polynomial ring S in n variables. We consider the Auslander-Reiten translate, Na_t, on the (derived) category of such modules. A monomial ideal I is positively t-determined if every generator x^a has a \leq t. We compute the multigraded cohomology- and betti spaces of Na_t^k(S/I) for every iterate k, and also the S-module structure of these cohomology modules. This comprehensively generalizes results of Hochster and Gräbe on local cohomology of Stanley-Reisner rings.
description: 35 pages, minor changes and corrections
The evolution of India's great power identity : a powerful performance
Creators: name: Sullivan, Katie Helen
Publisher: name: The Australian National University
Year: 2011
Subjects: subject: Realism Political aspects India
subject: International relations India
subject: Middle powers History 20th century
subject: Middle powers History 21st century
subject: Hegemony India

description: This research shows how Indian self-conceptions of 'greatness' have been derivative of India's own readings of an appropriate global role for itself at different periods during its history, rather than sourced from the dominant norms of 'great powerhood' in international society. It attempts to show how apparent shifts in India's identity can most aptly be understood as a process of India acquiring the material markers of a great power rather than actually becoming a great power. According to this reading, the Indian case diverges from the processes of socialisation typically associated with rising powers, whereby great power aspirants internalise the norms articulated by the existing community of great powers. In theoretical terms, the process of negotiation between the norms and values inherent in an Indian international self (an identity which I show to be relatively stable over time) and the norms and values of an international group of prominent states from which India seeks recognition of its 'right' to lead, is revealed as more complex than we might expect. By acquiring a deeper understanding of Indian conceptions of greatness, it is possible to reveal a more nuanced narrative of India's global ascendance and access complexities in India's conduct of external affairs that are sometimes missed by dominant frames of understanding in International Relations. The study demonstrates how attempts to narrate, observe or predict India's ascendance in the language of great powers can only incompletely capture the nuances of India's changing international identity and its potential role in the international system. As such, the research as a whole points to limitations in the theoretical rigour and the explanatory capacity of current dominant understandings of greatness as they are applied to rising powers such as India.
The development of phonological awareness and spelling competence in beginning spellers
Creators: name: Walton, Carol May
Publisher: name: University of British Columbia
Year: 2009

description: Phonological awareness is recognized as being a key factor contributing to students' development of early literacy skills. This study investigated the theoretical model which suggests that beginning spellers construct spellings using their knowledge of phonological awareness, orthography, letter names and letter sounds (Burns & Richgels, 1989; Read, 1986; Tangel & Blachman, 1995). Eighty-one kindergarten and grade one students were assessed in terms of their spelling competence, theory-related requisite skills (phonological awareness, knowledge, of orthographic structure, letter names and letter sounds), and several control variables (vocabulary, word recognition ability and verbal memory). The results indicted that a substantial portion of the variance in students' spelling competence was accounted for by these requisite skills, and that the contribution of phonological awareness skills to spelling remained significant even after controlling for differences in students' vocabulary, verbal memory and word recognition ability. Subsequent analyses demonstrated that particular types of phonological awareness tasks were differentially associated with different levels of spelling competence. These findings suggest that there is a strong relationship between the development of phonological awareness and spelling competence in beginning spellers.
On formal concepts of random formal contexts
Creators: name: Sakurai, Taro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Data Structures and Algorithms (cs.DS)
subject: Combinatorics (math.CO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: 68T30 (Primary) 06B99, 05C80, 60C05 (Secondary)

description: In formal concept analysis, it is well-known that the number of formal concepts can be exponential in the worst case. To analyze the average case, we introduce a probabilistic model for random formal contexts and prove that the average number of formal concepts has a superpolynomial asymptotic lower bound.
description: 7 pages, 2 figures, 1 table
Power and Pride Expression in Congressional Tweets
Creators: name: Riley, Will
name: Robinson, Dawn
Publisher: name: Zenodo
Year: 2019

description: Abstract:

Congresspersons are more likely to express pride on Twitter if they are female, liberal, not black, have less political experience, or are members of the U.S. Senate.  This provides mixed support for the hypothesis that politicians express pride to secure political power.  Congresspersons are less likely to express pride about targets related to the feminized profession of teacher if they are male, but no gender differences were detected for expressing pride about targets related to the masculinized profession of soldier.  This provides mixed support for the hypothesis that politicians express pride in accordance with their social identities.
Asymmetric depinning of chiral domain walls in ferromagnetic trilayers
Creators: name: de Jong, Mark C. H.
name: Avci, Can Onur
name: Hrabec, Aleš
name: Gambardella, Pietro
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We show that the coupling between two ferromagnetic layers separated by a nonmagnetic spacer can be used to control the depinning of domain walls and induce unidirectional domain wall propagation. We investigated CoFeB/Ti/CoFeB trilayers where the easy axis of the magnetization of the top CoFeB layer is out-of-plane and that of the bottom layer is in-plane. Using Magneto-optic Kerr effect microscopy, we find that the depinning of a domain wall in the perpendicularly magnetized CoFeB layer is influenced by the orientation of the magnetization of the in-plane layer, which gives rise to a field-driven asymmetric domain expansion. This effect occurs due to the magnetic coupling between the internal magnetization of the domain wall and the magnetization of the in-plane CoFeB layer, which breaks the symmetry of up-down and down-up homochiral Néel domain walls in the perpendicular CoFeB layer. Micromagnetic simulations support these findings by showing that the interlayer coupling either opposes or favors the Dzyaloshinskii-Moriya interaction in the domain wall, thereby generating an imbalance in the depinning fields. This effect also allows for artificially controlling the chirality and dynamics of domain walls in magnetic layers lacking a strong Dzyaloshinskii-Moriya interaction.
description: 21 pages, 6 figures
Boundaries of Positive Holomorphic Chains and the Relative Hodge Question
Creators: name: Harvey, F. Reese
name: Lawson, H. Blaine
Publisher: name: arXiv
Year: 2006
Subjects: subject: Complex Variables (math.CV)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 32C25, 32V99, 32Q99

description: We characterize the boundaries of positive holomorphic chains (with both compact and non-compact support) in an arbitrary complex manifold. We then consider a compact oriented real submanifold of dimension 2p-1 in a compact Kahler manifold X and address the question of which relative homology classes in H_{2p}(X,M;Z) are represented by positive holomorphic chains. Specifically, we define what it means for a class u in H_{2p}(X,M;Z) to be of type (p,p) and positive. It is then shown that u has these properties if and only if u = [T+S] where T is a positive holomorphic chain with dT = du and S is a positive (p,p)-current with dS = 0.
description: New sections have been added on the relative Hodge question: Which relative homology classes in H_{2p}(X,M;Z) are represented by positive holomorphic chains?
Measuring time delays: II. Using observations of the unresolved flux and astrometry
Creators: name: Springer, Ofer M.
name: Ofek, Eran O.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Lensed quasars and supernovae can be used to study galaxies' gravitational potential and measure cosmological parameters. The typical image separation of objects lensed by galaxies is of the order of 0.5". Therefore, finding the ones with small separations, and measuring their time-delays using ground-based observations is challenging. We suggest a new method to identify lensed quasars and simultaneously measure their time-delays, using seeing-limited synoptic observations in which the lensed quasar images and the lensing galaxy are unresolved. We show that using the light curve of the combined flux, and the astrometric measurements of the center-of-light position of the lensed images, the lensed nature of a quasar can be identified, and its time-delay can be measured. We provide the analytic formalism to do so, taking into account the measurement errors and the fact that the power spectra of quasar light curves is red (i.e., the light curve is highly correlated). We demonstrate our method on simulated data, while its implementation to real data will be presented in future papers. Our simulations suggest that, under reasonable assumptions, the new method can detect unresolved lensed quasars and measure their time delays, even when the image separation is below 0.1", or the flux ratio between the faintest and brightest images is as low as 0.03. Python and MATLAB implementations are provided. In a companion paper, we present a method for measuring the time delay using the combined flux observations. Although the flux-only method is less powerful, it may be useful in cases in which the astrometric information is not relevant (e.g., reverberation mapping).
description: Submitted to MNRAS, 16pp, 10 figures
Η ποικιλότητα της ελληνικής χλωρίδας με έμφαση στα λιβαδικά οικοσυστήματα
Creators: name: Θεοδωρίδης, Ιωάννης Θεοδώρου
Publisher: name: Aristotle University of Thessaloniki
Year: 2008
Subjects: Βιοποικιλότητα
Ενδημικά
Βάση δεδομένων
Αγρωστώδη
Ψυχανθή
Χλωριδικά στοιχεία
Biodiversity
Endemics
Data base
Poaceae
Fabaceae
Floristic elements

description: Οι στόχοι της έρευνας ήταν: η πλήρης καταγραφή των γνωστών ταξινομημάτων των Tracheobionta στην Ελλάδα, με βιβλιογραφική τεκμηρίωση της παρουσίας του κάθε ταξινιμήματος και μάλιστα της πρωτης αναφοράς του, η βιβλιογραφικά τεκμηριωμένη καταγραφή όλων των ενδημικών της Ελλάδας, η καταγραφή των σημαντικών χλωριδικών και οικολογικών χαρακτηριστικών των ταξινομημάτων των οικογενειών Poaceae και Fabaceae, που είναι οι σημαντικότερες για τα λιβαδικά οικοσυστήματα, και η δημιουργία ηλεκτρονικής βάσης δεδομένων στο διαδίκτυο που θα περιλαμβάνει τα παραπάνω δεδομένα. Τα αποτελέσματα της παρούσας έρευνας έδειξαν ο συνολικός αριθμός των φυτικών ταξινομημάτων της Ελληνικής βιοποικιλότητας είναι 6308, απ' τα οποία 1355(21,5%) είναι ενδημικά. Η επικρατέστερη βιοτική μορφή των ταξινομημάτων της Poaceae είναι τα Ημικρυπτόφυτα και έπειτα αυτά των θερόφυτων ενώ το αντίθετο παρατηρείται με αυτά της Fabaceae στην Ελλάδα. Η πλειοψηφία των ταξινομημάτων της Poaceae είναι πολυετή ενώ της Fabaceae μονοετή. Η συμβολή των ταξινομημάτων των δύο οικογενειών στη βλάστηση των υπολπικών κλιμακικού τύπου λιβαδιών είναι μικρή ενώ στα διαδοχικού τύπου της χαμηλής και ορεινής ζώνης μεγάλη. Τέλος, η συμβολή τους στην ενδημική χλωρίδα της Ελλάδας είναι μικρή καθώς και στην ποικιλότητα των δασολίβαδων.
description: The aims of the research were the record: of all known taxa of Tracheobionta in Greece with the first reference (were possible) of the presence of each taxa, of all Greek endemic taxa, of the important floristic and ecological elements of the taxa that belong to the families of Poaceae and Fabaceae, which are the most important to rangeland ecosystems and the creation of electronic database at the web that includes the previous data. The results have shown that the total number of Greek taxa comes up to 6308. The 1355(21,5%) of them are endemicy. The life form that prevails at Poaceae is the hemicreptophytes while at Fabaceae the therophytes. The majority of taxa of Poaceae are perennials, while of Fabaceae annuals. The contribution of both families to the diversity of subaleine grasslands is small while at those of low and montane zone bigger. Finally, their contribution to the endemic flora of Greece is small as it is at the diversity of forest rangelands.
A new evolutionary algorithm: Learner performance based behavior algorithm
Creators: name: Rahman, Chnoor M.
name: Rashid, Tarik A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computers and Society (cs.CY)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: A novel evolutionary algorithm called learner performance based behavior algorithm (LPB) is proposed in this article. The basic inspiration of LPB originates from the process of accepting graduated learners from high school in different departments at university. In addition, the changes those learners should do in their studying behaviors to improve their study level at university. The most important stages of optimization; exploitation and exploration are outlined by designing the process of accepting graduated learners from high school to university and the procedure of improving the learner's studying behavior at university to improve the level of their study. To show the accuracy of the proposed algorithm, it is evaluated against a number of test functions, such as traditional benchmark functions, CEC-C06 2019 test functions, and a real-world case study problem. The results of the proposed algorithm are then compared to the DA, GA, and PSO. The proposed algorithm produced superior results in most of the cases and comparative in some others. It is proved that the algorithm has a great ability to deal with the large optimization problems comparing to the DA, GA, and PSO. The overall results proved the ability of LPB in improving the initial population and converging towards the global optima. Moreover, the results of the proposed work are proved statistically.
description: 17 pages. Egyptian Informatics Journal, 2020
SSHOC archaeological case study Workshop - The Roman theatre in Catania from survey to interactive 4D visualisation
Creators: name: Schmidle, Wolfgang
name: Bucciero, Alberto
name: Demetrescu, Emanuel
name: Fanini, Bruno
name: Kritsotaki, Athina
name: Giuri, Francesco
name: Ferrari, Ivan
Publisher: name: Zenodo
Year: 2021
Subjects: Extended Matrix (EM) system
4D visualisation
CIDOC CRM
archaeology
reference ontology
EMViq tool

description: Archaeological field work is a complex process in which scientific resources and competences are allocated for long periods of time, sometimes years. However, the generated data is often either not available in digital form, stuck in data silos or not public. For this reason, the sustainability of archaeological research would benefit immensely from optimized and effective systems of digital documentation, analysis and visualisation of archaeological sites as well as from public, standardised data.

 This workshop presents an archaeological case study of an actual transition of archaeological survey data from data silos to the cloud. Based on survey data of the Roman theatre in Catania, we show how the data can be visualized as an interactive virtual reconstruction of the theatre. We show how the FAIR principles and semantic modelling can be applied to archaeological data in practice by standardizing and connecting data and systems from different sources. The absence of public data is also a cultural issue since shareholders are often afraid that the data quality might not be sufficient for publishing. The workshop represents a milestone in the work of the SSHOC task 5.7, and we would like to share our experiences with the audience and vice versa.

 In the first part of the workshop we present the case study as a work in progress. We look at the data and systems of the three partners, including an existing and a new visualisation of the Roman theatre and the Extended Matrix (EM) system. We conclude the first part with the integration process of systems and data that will lead to a unified workflow from survey data to an interactive 4D visualisation.

 In the second part we situate the case study in the broader context of the SSHOC project and beyond. Parallel presentations will report on the FAIR principles in archaeology, the SSHOC reference ontology and the EMViq tool that accompanies the EM system. We will then discuss where to go from here and especially how to integrate the FAIR principles and the reference ontology in our work.

 This workshop took place on 25 May 2021. A recording can be viewed at the SSHOC YouTube channel.
Multimessenger constraints on the dark matter interpretation of the Fermi-LAT Galactic center excess
Creators: name: Di Mauro, Mattia
name: Winkler, Martin Wolfgang
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: An excess of $γ$ rays in the data measured by the Fermi Large Area Telescope in the direction of the Galactic center has been reported in several publications. This excess, labeled as the Galactic center excess (GCE), is detected analyzing the data with different interstellar emission models, point source catalogs and analysis techniques. The characteristics of the GCE, recently measured with unprecedented precision, are all compatible with dark matter particles (DM) annihilating in the main halo of our Galaxy, even if other interpretations are still not excluded. We investigate the DM candidates that fit the observed GCE spectrum and spatial morphology. We assume a simple scenario with DM annihilating into a single channel but we inspect also more complicated models with two and three channels. We perform a search for a $γ$-ray flux from a list of 48 Milky Way dwarf spheroidal galaxies (dSphs) using state-of-the-art estimation of the DM density in these objects. Since we do not find any significant signal from the dSphs, we put upper limits on the annihilation cross section that result to be compatible with the DM candidate that fits the GCE. However, we find that the GCE DM signal is excluded by the AMS-02 $\bar{p}$ flux data for all hadronic and semi-hadronic annihilation channels unless the vertical size of the diffusion halo is smaller than 2 kpc -- which is in tension with radioactive cosmic ray fluxes and radio data. Furthermore, AMS-02 $e^+$ data rule out pure or mixed channels with a component of $e^+ e^-$. The only DM candidate that fits the GCE spectrum and is compatible with constraints obtained with the combined dSphs analysis and the AMS-02 $\bar{p}$ and $e^+$ data annihilates purely into $μ^+μ^-$, has a mass of 60 GeV and roughly a thermal cross section.
description: 25 pages, 15 figures. Submitted to PRD. Comments are welcome