cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Two phase reheating: CMB constraints on inflaton and dark matter phenomenology
Creators: name: Haque, Md Riajul
name: Maity, Debaprasad
name: Saha, Pankaj
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We propose a two-phase reheating scenario where the initial preheating dynamics is described by an effective dynamics followed by the standard perturbative reheating. Some of the important universal results of lattice simulation during preheating have been considered as crucial inputs in our two-phase dynamics. In this framework, detailed phenomenological constraints have been obtained on the inflaton couplings with reheating fields, and dark matter parameters in terms of CMB constrained inflationary scalar spectral index. It is observed that the conventional reheating scenario generically predicts the maximum reheating temperature $T_{re}^{max} \simeq 10^{15}$ GeV, corresponding to an almost instantaneous transition from the end of inflation to radiation domination. This fact will naturally lead to the problem of non-perturbative inflaton decay, which is in direct conflict with the perturbative reheating itself. Taking into account this by incorporating effective non-perturbative dynamics as the initial phase, our model of two-phase reheating scenarios also predicts model-independent maximum reheating temperature, which does not correspond to the instantaneous process. Further, $T_{re}^{max}$ is predicted to lie within $(10^{13}, 10^{10})$ GeV if CMB constraints on inflaton couplings with different reheating field are taken into account. We have further studied in detail the dark matter phenomenology in a model-independent manner and show how dark matter parameter space can be constrained through CMB parameters via the inflaton spectral index. Considering dark matter production during reheating via the Freeze-in mechanism, its parameter space has been observed to be highly constrained by our two-phase reheating than the constraints predicted by the conventional reheating scenarios, which are believed to theoretically incomplete.
description: 63 pages, 29 figures, An expanded version of this paper arxiv number: 1709.00251
Adaptive sampling of pressure distribution features for the airfoil statistical analysis
Creators: name: Li, Runze
name: Zhang, Yufei
name: Chen, Haixin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In the area of supercritical wing design, a variety of principles, laws and rules have been summarized by scholars who perform theoretical and experimental analyses. The applicability of these rules is usually restricted by the airfoil samples investigated. With the advance of computational fluid dynamics and computational intelligence, such work can be better conducted on computers. The present paper proposes an output space sampling method to generate airfoil samples that have specified pressure distributions or meet certain special requirements. The well-selected and distributed samples are then utilized for statistical studies to obtain more reliable or more universal aerodynamics rules that can be used as guidance in the process of supercritical airfoil design. The capabilities of the output space sampling method in regard to filling the space and exploring the boundaries are also improved. The output space sampling method is employed to generate supercritical airfoil samples with different requirements, allowing the relationships between the shock wave location and the drag divergence Mach number as well as the drag creep characteristic to be revealed.
description: 25 pages, 15 figures
Narrative Strategy of Ethnic Minority Films in Guizhou After 2000
Creators: name: Zijia Liu
Publisher: name: The Center of Excellence of Kalasin Phraewa Traditional Textiles of Kalasin University
Year: 2023
Subjects: Narrative strategy
Ethnic minorities
Film, Guizhou

description: Asian Journal of Traditional and Innovative Arts and Textiles, 2, 3, 75-87
Extreme fluctuations in noisy task-completion landscapes on scale-free networks
Creators: name: Guclu, H.
name: Korniss, G.
name: Toroczkai, Z.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the statistics and scaling of extreme fluctuations in noisy task-completion landscapes, such as those emerging in synchronized distributed-computing networks, or generic causally-constrained queuing networks, with scale-free topology. In these networks the average size of the fluctuations becomes finite (synchronized state) and the extreme fluctuations typically diverge only logarithmically in the large system-size limit ensuring synchronization in a practical sense. Provided that local fluctuations in the network are short-tailed, the statistics of the extremes are governed by the Gumbel distribution. We present large-scale simulation results using the exact algorithmic rules, supported by mean-field arguments based on a coarse-grained description.
description: 16 pages, 6 figures, revtex
Η κοινωνία των πολιτών και ο οργανικός διανοούμενος για τον Antonio Gramsci και τη σύγχρονη εποχή:
Creators: name: Ζέικου, Αναστασία Στυλιανού
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Κοινωνία των πολιτών
Οργανικός διανοούμενος
Αντόνιο Γκράμσι
Civil society
Organic dianooumenos
Antonio Gramsci

description: Ο Γκράμσι προσδιορίζει α) την «πολιτική κοινωνία» δηλαδή το κράτος και το νομοθετικό καθεστώς και β) την «κοινωνία των πολιτών» δηλαδή το σύνολο των οργανισμών που καλούνται ιδιωτικοί. Για τον Γκράμσι η κοινωνία των πολιτών αποτελεί μια κοινωνική δομή που βρίσκεται σε διαρκή διαλεκτική σχέση τόσο με το κράτος όσο και με την υλική βάση της κοινωνίας. Επιπλέον για τον Γκράμσι διανοούμενοι δεν είναι απλά οι σκεπτόμενοι άνθρωποι αλλά αυτοί που τους δίνεται η δυνατότητα να ασκούν μια πνευματική λειτουργία. Τέλος διακρίνει τους διανοούμενους σε «παραδοσιακούς» και «οργανικούς». Κάθε καινούργια ιστορικά κοινωνική ομάδα δημιουργεί και φέρει στο προσκήνιο οργανικά μαζί της ένα ή περισσότερα στρώματα διανοούμενων κυρίως ασχολούνται με το οικονομικό, πολιτικό και κοινωνικό πεδίο.
description: Gramsci identifies a) the "civil society", the state and the legislative regime and b) the "civil society" that all organizations are private. For Gramsci, the civil society is a social structure that is in constant dialectical relationship with both the state and the material basis of society. In addition to Gramsci scholars are not just thinking people but those who enable them to perform a spiritual function. Finally distinguished intellectuals 'traditional' and 'organic'. Any new social group historically created and brought to the forefront of institutions of one or more layers of intellectuals mainly engaged in the economic, political and social fields.
Molecular Gas in NUclei of GAlaxies (NUGA): VI. Detection of a molecular gas disk/torus via HCN in the Seyfert2 galaxy NGC6951?
Creators: name: Krips, M.
name: Neri, R.
name: Garcia-Burillo, S.
name: Combes, F.
name: Schinnerer, E.
name: Baker, A. J.
name: Eckart, A.
name: Boone, F.
name: Hunt, L.
name: Leon, S.
name: Tacconi, L. J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Several studies of nearby active galaxies indicate significantly higher HCN-to-CO intensity ratios in AGN than in starburst (SB) environments. HCN enhancement can be caused by many different effects, such as higher gas densities/temperatures, UV/X-ray radiation, and non-collisional excitation. As active galaxies often exhibit intense circumnuclear SB, high angular resolution/sensitivity observations are of paramount importance to disentangling the influence of SB from that of nuclear activity on the chemistry of the surrounding molecular gas. The tight relation of HCN enhancement and nuclear activity may qualify HCN as an ideal tracer of molecular gas close to the AGN, providing complementary and additional information to that gained via CO. NGC6951 houses nuclear and SB activity, making it an ideal testbed in which to study the effects of different excitation conditions on the molecular gas. We used the new ABCD configurations of the IRAM PdBI to observe HCN(1-0) in NGC6951 at high angular resolution (1''). We detect very compact (<50pc) HCN emission in its nucleus, supporting previous hints of nuclear gas structure. Our observations also reveal HCN emission in the SB ring and resolve it into several peaks, leading to a higher coincidence between the HCN and CO distributions than previously reported. We find a significantly higher HCN-to-CO intensity ratio (>0.4) in the nucleus than in the SB ring (0.02-0.05). As for NGC1068, this might result from a higher HCN abundance in the centre due to an X-ray dominated gas chemistry, but a higher gas density/temperature or additional non-collisional excitation of HCN cannot be entirely ruled out, based on these observations. The compact HCN emission is associated with rotating gas in a circumnuclear disk/torus.
description: Letter accepted for publication in a special issue of A&A presenting results of the new extended configuration at the IRAM PdBI, to appear most likely around June 2007. Letter has 4 pages and 2 figures. Abstract has been shortened to meet the line limits of astrop-ph
Integral field spectroscopy of H-alpha emission in cooling flow cluster cores: disturbing the molecular gas reservoir
Creators: name: Wilman, R. J.
name: Edge, A. C.
name: Swinbank, A. M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present optical integral field spectroscopy of the H-alpha-luminous (>1E42 erg/s) central cluster galaxies in the cores of the cooling flows A1664, A1835, A2204 and Zw8193. From the [NII]+H-alpha complex we derive 2-D views of the distribution and kinematics of the emission line gas, and further diagnostics from the [SII] and [OI] lines. The H-alpha emission shows a variety of disturbed morphologies with velocity gradients and splittings of several hundred km/s on scales of 20 kpc or more. Despite the small sample size, there are some generic features. The most disturbed H-alpha emission appears to be associated with secondary galaxies within 10-20 kpc (projected) of the central galaxy and close in velocity to the H-alpha. The global H-alpha kinematics match those of CO(1-0) emission in single-dish data. The [NII]/H-alpha, [SII]/H-alpha and [OI]/H-alpha ratios vary little with position, local H-alpha surface brightness or between clusters. We propose that the H-alpha and CO emission arise in molecular clouds heated by a starburst which has been triggered by interaction with a secondary galaxy. Such CO emission is known to trace massive (>1E10 M_sun) compact (<20 kpc) reservoirs of cool molecular gas, which an infalling galaxy may disturb, distorting the H-alpha morphology and initiating widespread star formation. We suggest that cloud-cloud collisions in the undisturbed molecular gas reservoir might be an important excitation source for the emission line gas in the cores of lower H-alpha luminosity cluster cores with less intense star formation (abridged).
description: 15 pages, 16 figures (7 with essential colour), accepted by MNRAS
Waveguide coupled cavity-enhanced light emission from individual carbon nanotubes
Creators: name: Yamashita, D.
name: Machiya, H.
name: Otsuka, K.
name: Ishii, A.
name: Kato, Y. K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We demonstrate an individual single-walled carbon nanotube light emitter integrated onto a microcavity and a waveguide operating in the telecom wavelength regime. Light emission from the carbon nanotube is enhanced at the cavity resonance and is efficiently extracted from the waveguide facet. We have transferred carbon nanotubes to a nanobeam cavity with a dry process, ensuring that an individual carbon nanotube is used. The guided light emission from a chirality-identified single carbon nanotube has a narrow linewidth of less than 1.3 nm and an off-resonance rejection of $\sim$17 dB. The waveguide-coupled device configuration is compatible with fully integrated on-chip designs and is promising for carbon-nanotube-based photonics.
description: 5 pages, 4 figures
Systematics of the first 2+ excitation with the Gogny interaction
Creators: name: Bertsch, G. F.
name: Girod, M.
name: Hilaire, S.
name: Delaroche, J. -P.
name: Goutte, H.
name: Pe'ru, S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We examine the global performance of an extended self-consistent mean field theory of 2+ excitations in even-even nuclei. 518 nuclei are included in our survey, comprising all but 39 of the known nuclei tabulated by Raman et al. The theory is based on a quantal collective Hamiltonian in five dimensions in which the potential energy and the tensor of inertia are obtained from constrained triaxial Hartree-Fock-Bogoliubov calculations. The only parameters in theory are those of the finite-range, density-dependent Gogny D1S interaction. The following properties of the lowest 2+ excitations are calculated: excitation energy, reduced transition probability, and spectroscopic quadrupole moment. We find that the theory is very reliable to classify the nuclei by shape. Quantitatively the performance of the theory in deformed nuclei is excellent: average excitation energies and transition quadrupole moments are within 5% of the experimental values, and the dispersion about the averages are 20% and 10%, respectively. The performance is not as good on spherical and soft nuclei. Including all nuclei in the performance evaluation, the average transition quadrupole moment is 10% too high and the dispersion about the mean is 20%. For the energies, the average is 13% too high and the dispersion is 40%.
description: 4 pages with 5 figures and 1 table; this version is a resubmission to Phys. Rev. Lett. including changes in response to referee comments
Μέθοδοι προσαρμοστικής υποστήριξης εκπαιδευομένων σε συνεργατικά περιβάλλοντα μάθησης:
Creators: name: Ψαθάς, Γεώργιος Απόστολου
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Συνεργατική μάθηση
Πρότυπα προσαρμογής
Προσαρμοστική βοήθεια
Computer Supported Collaborative Learning
Adaptation Patterns
Adaptive Support

description: Αντικείμενο της παρούσας εργασίας είναι η παρουσίαση του FlexColLab (Flexible Collaboration Laboratory), ενός πρωτότυπου εργαλείου το οποίο υλοποιεί τα υποδείγματα προσαρμογής (Adaptation patterns). Ένα υπόδειγμα προσαρμογής περιγράφεται ως μια χρήσιμη και καλά στοχευμένη διαδικασία προσαρμογής η οποία μπορεί να ενεργοποιηθεί από τον καθηγητή σε συνεργατικά περιβάλλοντα μάθησης υποστηριζόμενα από υπολογιστές (CSCL), με σκοπό να δημιουργηθεί ένα βελτιωμένο περιβάλλον μάθησης, όταν συγκεκριμένες συνθήκες παρουσιάζονται κατά τη διάρκεια εκτέλεσης μιας συνεργατικής δραστηριότητας. Το FlexColLab βοηθάει τους καθηγητές στο σχεδιασμό των δικών τους συνεργατικών δραστηριοτήτων, κάνοντας παραμετροποίηση και επαναχρησιμοποίηση των υποδειγμάτων προσαρμογής, σύμφωνα με τις απαιτήσεις του εκάστοτε μαθησιακού στόχου. Δύο (2) υποδείγματα προσαρμογής έχουν υλοποιηθεί στο περιβάλλον του FlexColLab, αυτά του “Advance the Advanced” και “Support group of Novices”, τα οποία και παρουσιάζονται στη παρούσα εργασία. Επιπλέον, παρουσιάζεται και το θεωρητικό υπόβαθρο των υποδειγμάτων προσαρμογής.
description: This work presents FlexColLab (Flexible Collaboration Laboratory), a prototype tool that implements adaptation patterns. An adaptation pattern is described as a pedagogically useful and well-targeted adjustment process that can be initiated by the teacher or the CSCL system, in order to foster an improved learning setting when specific conditions occur during the collaborative learning activity. FlexColLab helps teachers in the process of creating their own potentially effective dynamic collaborative activities by reusing and customizing adaptation patterns, according to the requirements of a particular learning situation. “Advance the advanced” and “Support group of novices” are two adaptation patterns implemented by FlexColLab, and they are presented also in the paper. Additionally the theoretical background of adaptation patterns is also discussed.
Entanglement Entropy Inequalities in BCFT by Holography
Creators: name: Chou, Chia-Jui
name: Lin, Bo-Han
name: Wang, Bin
name: Yang, Yi
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study entanglement entropy inequalities in boundary conformal field theory (BCFT) by holographic correspondence. By carefully classifying all the configurations for different phases, we prove the strong subadditiviy and the monogamy of mutual information for holographic entanglement entropy in BCFT at both zero and finite temperatures
description: 35 pages, 20 figures
Self ordering and superradiant backscattering of a gaseous beam in a ring cavity with counter propagating pump
Creators: name: Maes, C.
name: Asboth, J.
name: Ritsch, H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the threshold conditions of spatial self organization combined with collective coherent optical backscattering of a thermal gaseous beam moving in a high Q ring cavity with counter propagating pump. We restrict ourselves to the limit of large detuning between the particles optical resonances and the light field, where spontaneous emission is negligible and the particles can be treated as polarizable point masses. Using a linear stability analysis in the accelerated rest frame of the particles we derive an analytic bounds for the selforganization as a function of particle number,average velocity, temperature and resonator parameters. We check our results by a numerical iteration procedure as well as by direct simulations of the N-particle dynamics. Due to momentum conservation the backscattered intensity determines the average force on the cloud, which gives the conditions for stopping and cooling a fast molecular beam.
description: 18 pages 11 figures
Gisin's theorem for two d-dimensional systems based on the Collins-Gisin-Linden-Masser-Popescu inequality
Creators: name: Chen, Jing-Ling
name: Deng, Dong-Ling
name: Hu, Ming-Guang
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this Rapid Communication, we show analytically that all pure entangled states of two d-dimensional systems (qudits) violate the Collins-Gisin-Linden-Masser-Popoescu (CGLMP) inequality. Thus one has the Gisin's theorem for two qudits.
description: 4 pages, 1 figure, accepted for publication as a Rapid Communication in Physical Review A
The DeRisk database: Extreme Design Waves for Offshore Wind Turbines
Creators: name: Pierella, Fabio
name: Lindberg, Ole
name: Bredmose, Henrik
name: Bingham, Harry B.
name: Read, Robert W.
name: Engsig-Karup, Allan Peter
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The estimation of extreme loads from waves is an essential part of the design of an offshore wind turbine. Standard design codes suggest to either use simplified methods based on regular waves, or to perform fully nonlinear computations. The former might not provide an accurate representation of the extreme waves, while the latter is computationally too intensive for design iterations. We address these limitations by using the fully nonlinear solver OceanWave3D to establish the DeRisk database, a large dataset of extreme waves kinematics in a two-dimensional domain. From the database, which is open and freely available, a designer can extract fully-nonlinear wave kinematics for a wave condition and water depth of interest by identifying a suitable computation in the database and, if needed, by Froude-scaling the kinematics. The nonlinear solver is validated against the DeRisk model experiments at two different water depths, $33.0 [m]$ and $20.0 [m]$, and an excellent agreement is found for the analyzed cases. The experiments are used to calibrate OceanWave3D's numerical breaking filter constant, and the best agreement is found for $β=0.5$. We compare the experimental static force with predictions by the DeRisk database and the Rainey force model, and with state-of-the-art industrial practices. For milder storms, we find a good agreement in the predicted extreme force between the present methodology and the standard methodologies. At the deep location and for stronger storms, the largest loads are given by slamming loads due to breaking waves. In this condition, the database methodology is less accurate than the embedded stream function method and more accurate than the WiFi JIP methodology, providing generally nonconservative estimates. For strong storms at the shallower location, where wave breaking is less dominating, the database methodology is the most accurate overall.
description: Submitted to Marine Structures (Elsevier), 46 pages, 16 figures, 6 tables. The database associated with the publication is available at https://data.dtu.dk/articles/dataset/The_DeRisk_Database/10322033
Structurally dynamic spin market networks
Creators: name: Horvath, D.
name: Kuscsik, Z.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Statistical Finance (q-fin.ST)
subject: FOS: Physical sciences
subject: FOS: Economics and business

description: The agent-based model of stock price dynamics on a directed evolving complex network is suggested and studied by direct simulation. The stationary regime is maintained as a result of the balance between the extremal dynamics, adaptivity of strategic variables and reconnection rules. The inherent structure of node agent "brain" is modeled by a recursive neural network with local and global inputs and feedback connections. For specific parametric combination the complex network displays small-world phenomenon combined with scale-free behavior. The identification of a local leader (network hub, agent whose strategies are frequently adapted by its neighbors) is carried out by repeated random walk process through network. The simulations show empirically relevant dynamics of price returns and volatility clustering. The additional emerging aspects of stylized market statistics are Zipfian distributions of fitness.
description: 13 pages, 5 figures, accepted in IJMPC, references added, minor changes in model, new results and modified figures
Isolated and group environment dependence of stellar mass and different star formation rates
Creators: name: Privatus, Pius
name: Goswami, Umananda Dev
Publisher: name: arXiv
Year: 2024
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In this study, we explored the impact of isolated and group environments on stellar mass, star formation rate (SFR), and specific star formation rate (SSFR, i.e., the rate of star formation per unit stellar mass) using the galaxy dataset from the Sloan Digital Sky Survey Data Release 12 (SDSS DR12) for $z\lesssim0.2$. To mitigate the Malmquist bias, we partitioned the entire dataset into fifteen subsamples with a redshift bin size of $Δz = 0.01$ and examined the environmental dependencies of these properties within each redshift bin. A strong correlation between environment, stellar mass, SFR, and SSFR was observed across nearly all redshift bins. In the lower redshift bins $(z<0.1)$, the proportion of galaxies within the isolated environment exceeded that within the group environment. On the other hand, in the higher redshift bins $(z\geq 0.12)$, the isolated environment's galaxy fraction is found to be lower than that of the group environment. For the intermediate redshift bins $(0.1 \leq z < 0.12)$, an approximately equal proportion of galaxies is observed in both isolated and group environments.
description: 11 pages and 4 figures
A Survey on Decentralized Identifiers and Verifiable Credentials
Creators: name: Mazzocca, Carlo
name: Acar, Abbas
name: Uluagac, Selcuk
name: Montanari, Rebecca
name: Bellavista, Paolo
name: Conti, Mauro
Publisher: name: arXiv
Year: 2024
Subjects: subject: Cryptography and Security (cs.CR)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Digital identity has always been considered the keystone for implementing secure and trustworthy communications among parties. The ever-evolving digital landscape has gone through many technological transformations that have also affected the way entities are digitally identified. During this digital evolution, identity management has shifted from centralized to decentralized approaches. The last era of this journey is represented by the emerging Self-Sovereign Identity (SSI), which gives users full control over their data. SSI leverages decentralized identifiers (DIDs) and verifiable credentials (VCs), which have been recently standardized by the World Wide Web Community (W3C). These technologies have the potential to build more secure and decentralized digital identity systems, remarkably contributing to strengthening the security of communications that typically involve many distributed participants. It is worth noting that the scope of DIDs and VCs extends beyond individuals, encompassing a broad range of entities including cloud, edge, and Internet of Things (IoT) resources. However, due to their novelty, existing literature lacks a comprehensive survey on how DIDs and VCs have been employed in different application domains, which go beyond SSI systems. This paper provides readers with a comprehensive overview of such technologies from different perspectives. Specifically, we first provide the background on DIDs and VCs. Then, we analyze available implementations and offer an in-depth review of how these technologies have been employed across different use-case scenarios. Furthermore, we examine recent regulations and initiatives that have been emerging worldwide. Finally, we present some challenges that hinder their adoption in real-world scenarios and future research directions.
description: 32 pages, 15 figures, and 10 tables
The SUGRA Quintessence Model Coupled to the MSSM
Creators: name: Brax, Philippe
name: Martin, Jerome
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
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: We study the cosmological evolution of the universe when quintessence is modeled within supergravity, supersymmetry is broken in a hidden sector, and we also include observable matter in a third independent sector. We find that the presence of hidden sector supersymmetry breaking leads to modifications of the quintessence potential. We focus on the coupling of the SUGRA quintessence model to the MSSM and investigate two possibilities. First one can preserve the form of the SUGRA potential provided the hidden sector dynamics is tuned. The currently available limits on the violations of the equivalence principle imply a universal bound on the vacuum expectation value of the quintessence field now, κ^{1/2}Q\ll 1. On the other hand, the hidden sector fields may be stabilised leading to a minimum of the quintessence potential where the quintessence field acquires a mass of the order of the gravitino mass, large enough to circumvent possible gravitational problems. However, the cosmological evolution of the quintessence field is affected by the presence of the minimum of the potential. The quintessence field settles down at the bottom of the potential very early in the history of the universe. Both at the background and the perturbation levels, the subsequent effect of the quintessence field is undistinguishable from a pure cosmological constant
description: 33 pages, 7 figures
Long-range nontopological edge currents in charge-neutral graphene
Creators: name: Aharon-Steinberg, Amit
name: Marguerite, Arthur
name: Perello, David J.
name: Bagani, Kousik
name: Holder, Tobias
name: Myasoedov, Yuri
name: Levitov, Leonid S.
name: Geim, Andre K.
name: Zeldov, Eli
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Van der Waals heterostructures display a rich variety of unique electronic properties. To identify novel transport mechanisms, nonlocal measurements have been widely used, wherein a voltage is measured at contacts placed far away from the expected classical flow of charge carriers. This approach was employed in search of dissipationless spin and valley transport, topological charge-neutral currents, hydrodynamic flows and helical edge modes. Monolayer, bilayer, and few-layer graphene, transition-metal dichalcogenides, and moire superlattices were found to display pronounced nonlocal effects. However, the origin of these effects is hotly debated. Graphene, in particular, exhibits giant nonlocality at charge neutrality, a prominent behavior that attracted competing explanations. Utilizing superconducting quantum interference device on a tip (SQUID-on-tip) for nanoscale thermal and scanning gate imaging, we demonstrate that the commonly-occurring charge accumulation at graphene edges leads to giant nonlocality, producing narrow conductive channels that support long-range currents. Unexpectedly, while the edge conductance has little impact on the current flow in zero magnetic field, it leads to field-induced decoupling between edge and bulk transport at moderate fields. The resulting giant nonlocality both at charge neutrality and away from it produces exotic flow patterns in which charges can flow against the global electric field. We have visualized surprisingly intricate patterns of nonlocal currents, which are sensitive to edge disorder. The observed one-dimensional edge transport, being generic and nontopological, is expected to support nonlocal transport in many electronic systems, offering insight into numerous controversies in the literature and linking them to long-range guided electronic states at system edges.
description: Main text: 14 pages, 4 figures. Methods and Supplementary information: 27 pages, 6 figures. Supplementary videos: 9
Quantum finite-time thermodynamics: insight from a single qubit engine
Creators: name: Dann, Roie
name: Kosloff, Ronnie
name: Salamon, Peter
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Incorporating time into thermodynamics allows addressing the tradeoff between efficiency and power. A qubit engine serves as a toy model to study this tradeoff from first principles, based on the quantum theory of open systems. We study the quantum origin of irreversibility, originating from heat transport, quantum friction and thermalization in the presence of external driving. We construct various finite-time engine cycles based on the Otto and Carnot templates. Our analysis highlights the role of coherence and the quantum origin of entropy production.
Magnetic microswimmers exhibit Bose-Einstein-like condensation
Creators: name: Meng, Fanlong
name: Matsunaga, Daiki
name: Mahault, Benoît
name: Golestanian, Ramin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Physical sciences

description: We study an active matter system comprised of magnetic microswimmers confined in a microfluidic channel and show that it exhibits a new type of self-organized behavior. Combining analytical techniques and Brownian dynamics simulations, we demonstrate how the interplay of non-equilibrium activity, external driving, and magnetic interactions leads to the condensation of swimmers at the center of the channel via a non-equilibrium phase transition that is formally akin to Bose-Einstein condensation. We find that the effective dynamics of the microswimmers can be mapped onto a diffusivity-edge problem, and use the mapping to build a generalized thermodynamic framework, which is verified by a parameter-free comparison with our simulations. Our work reveals how driven active matter has the potential to generate exotic classical non-equilibrium phases of matter with traits that are analogous to those observed in quantum systems.
La estructura y la función del emblema en el teatro de Tirso de Molina
Creators: name: Restrepo-Gautier, Pablo
Publisher: name: University of British Columbia
Year: 2009

description: In 1531, Andreas Alciatus published the first emblem book, Emblematum liber. It consisted of a series of illustrations, each with a motto and an epigram. Emblem writers tried to create a universal language that would communicate ideas through visual images, but felt it necessary to add explanations to avoid the misinterpretation of their compositions. The result was the complex relationship between verbal and pictorial elements that characterizes the emblematic mode of thinking. Emblem books and the emblematic mode permeated European society and culture in the sixteenth and seventeenth centuries. Emblematic images appeared in decorations, pageants, clothing and other expressions of culture including literature and the theatre. This thesis studies the relationship between emblem and theatre in the dramatic production of the Spanish playwright Tirso de Molina (1584-1648). Two main questions are explored: how do emblems appear in Tirso de Molina's drama? and, what function do they perform? The first question deals with how the emblematic form passes from a static medium, the printed page, to a dynamic one, the theatre. The second one explores the function that the emblem and the emblematic mode play within specific plays. The method is based on a case-by-case study. Each example of an emblem in Tirso's dramatic production is studied separately to see how it becomes theatre and how it behaves within the confines of the play. This approach allows general conclusions to be drawn about how the emblem works in the theatre and opens the way to more structural or theoretical studies. The thesis shows that the emblematic form appears abundantly and in a variety of ways in Tirso de Molina's plays. Although the emblematic form may keep its original structure when it becomes dramatized, it may also lose one or several of its parts. The original emblematic structure sometimes disappears and only the relationship between image and word, characteristic of the emblematic mode, remains. Finally, it is shown that the emblematic form in the theatre can play both a dramatic and an ideological role.
Η επίδραση των διαφόρων μορφών διδασκαλίας στις στρατηγικές μάθησης μαθητών της Β΄ βάθμιας εκπαίδευσης:
Creators: name: Κατσάνη, Κονδυλένια Κλωνάρη
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Συνεργατική μάθηση
Στρατηγικές μάθησης
Κλίμα κινήτρων
Cooperative learning
Learning strategies
Internal motivation

description: Η παρούσα μελέτη αποσκοπούσε αφενός στη σύγκριση της πρακτικής με την συνεργατική και την μετωπική διδασκαλία και αφετέρου στη διερεύνηση του πώς η καθεμία επηρεάζει τις προσωπικές στρατηγικές μάθησης σε ανομοιογενείς ομάδες μαθητών, σε μια διδακτική μονάδα. Στην έρευνα συμμετείχαν 300 μαθητές/-τριες από 13 έως 16 ετών. Για την εκτίμηση των κινήτρων χρησιμοποιήθηκαν το Situational Motivation Scale και το Motivated Strategies for Learning Questionnaire. Το ερώτημα που τέθηκε ήταν αν η συνεργατική σε σχέση με τη μετωπική διδασκαλία, έχει καλύτερα αποτελέσματα στην αυτορρύθμιση και αν βελτιώνονται τα εσωτερικά κίνητρα. Για την εξέταση των υποθέσεων εφαρμόστηκε ανάλυση διακύμανσης. Τα αποτελέσματα έδειξαν ότι υπήρξαν στατιστικά σημαντικές διαφορές [F(3.26 ) = 2.75, p < .05] στην αναζήτηση βοήθειας. Προέκυψε ότι οι μαθητές/-τριες της συνεργατικής διδασκαλίας σε σχέση με αυτούς που συμμετείχαν στη μετωπική και την ομάδα ελέγχου είχαν υψηλότερες τιμές. Επομένως, το μάθημα φυσικής αγωγής πρέπει να σχεδιάζεται με τρόπο που να ενισχύει τα εσωτερικά κίνητρα και τις στρατηγικές μάθησης των μαθητών καθώς αυτά συνδέονται με θετικά αποτελέσματα. Αυτό πρακτικά σημαίνει, παροχή επιλογών στους μαθητές, ευκαιρίες εμπλοκής στη διαμόρφωση του μαθήματος, προσανατολισμό του μαθήματος στη μάθηση, έμφαση στην προσωπική βελτίωση, στην ενίσχυση της συνεργασίας και όχι στον ανταγωνισμό μεταξύ των μαθητών.
description: This study aimed to compare practice and collaborative teaching methods and to explore how each of them affects personal learning strategies to diverse groups of students in a teaching unit. The survey involved 300 students from 13 to 16 years old. The Situational Motivation Scale and the Motivated Strategies for Learning Questionnaire was used. It was examined whether cooperative learning improved self-regulation and enhanced internal motivation. The results showed that there was statistical significance [F (3.26) = 2.75, p
ANTHROPONYMS IN DIFFERENT FORMS OF ADDRESS IN ENGLISH AND GERMAN
Creators: name: Masariddinova, R.H.
Publisher: name: Zenodo
Year: 2024

description: In English and German, personal names (variants and derivatives of names) and surnames can be used as addresses. In everyday communication between family members, the most common forms of the abbreviated name (English John, Cary, German Ann, Tob ), their variants formed using suffixes (English Jonny , Carie , German Anchen , Tobi ). English and German languages have an expressive way of word formation of anthroponyms, i.e. suffixes can have their own emotional and/or evaluative meaning, characterizing not only the bearer of the name, but also the name giver . Compared to the German language, the English language has a significantly smaller set of word-forming suffixes. This conclusion is confirmed by the words of M. Epstein: “English, by simplifying, reduced the word to a nominative and informative root, to an informative unit, free from expressive layers.” Let's consider the basic rules for using personal names in the field of interpersonal communication. Communication in English and German is impossible to imagine without the use of surnames and personal names. The second and third names are used very rarely in spoken language. The full form of the anthroponymic formula is used only in documents, certificates, official papers, etc.
Capture Steps: Robust Walking for Humanoid Robots
Creators: name: Missura, Marcell
name: Bennewitz, Maren
name: Behnke, Sven
Publisher: name: arXiv
Year: 2020
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Stable bipedal walking is a key prerequisite for humanoid robots to reach their potential of being versatile helpers in our everyday environments. Bipedal walking is, however, a complex motion that requires the coordination of many degrees of freedom while it is also inherently unstable and sensitive to disturbances. The balance of a walking biped has to be constantly maintained. The most effective way of controlling balance are well timed and placed recovery steps -- capture steps -- that absorb the expense momentum gained from a push or a stumble. We present a bipedal gait generation framework that utilizes step timing and foot placement techniques in order to recover the balance of a biped even after strong disturbances. Our framework modifies the next footstep location instantly when responding to a disturbance and generates controllable omnidirectional walking using only very little sensing and computational power. We exploit the open-loop stability of a central pattern generated gait to fit a linear inverted pendulum model to the observed center of mass trajectory. Then, we use the fitted model to predict suitable footstep locations and timings in order to maintain balance while following a target walking velocity. Our experiments show qualitative and statistical evidence of one of the strongest push-recovery capabilities among humanoid robots to date.
Interatomic van der Waals potential in the presence of a magneto-electric sphere
Creators: name: Safari, Hassan
name: Welsch, Dirk-Gunnar
name: Dung, Ho Trung
name: Buhmann, Stefan Yoshi
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: On the basis of a general formula obtained earlier via fourth-order erturbation theory within the framework of macroscopic quantum electrodynamics, the van der Waals potential between two neutral, unpolarized, ground-state atoms in the presence of a homogeneous, dispersing and absorbing magnetoelectric sphere is studied. When the radius of the sphere becomes sufficiently large, the result asymptotically agrees with that for two atoms near a planar interface. In the opposite limit of a very small sphere, the sphere can effectively be regarded as being a third ground-state atom, and the nonadditive three-atom van der Waals potential is recovered. To illustrate the effect of a sphere of arbitrary radius, numerical results are presented for the triangular arrangement where the atoms are at equidistance from the sphere, and for the linear arrangement where the atoms and the sphere are aligned along a straight line. As demonstrated, the enhancement or reduction of the interaction potential in the presence of purely electric or magnetic spheres can be physically understood in terms of image charges.
description: 13 pages, 7 figures
Anisotropic fluid dynamical simulations of heavy-ion collisions
Creators: name: McNelis, M.
name: Bazow, D.
name: Heinz, U.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present VAH, a (3+1)-dimensional simulation that evolves the far-from-equilibrium quark-gluon plasma produced in ultrarelativistic heavy-ion collisions with anisotropic fluid dynamics. We solve the hydrodynamic equations on an Eulerian grid using the Kurganov-Tadmor algorithm in combination with a new adaptive Runge-Kutta method. Our numerical scheme allows us to start the simulation soon after the nuclear collision, largely avoiding the need to integrate it with a separate pre-equilibrium dynamics module. We test the code's performance by simulating on the Eulerian grid conformal and non-conformal Bjorken flow as well as conformal Gubser flow, whose (0+1)-dimensional solutions are precisely known. Finally, we compare non-conformal anisotropic hydrodynamics to second-order viscous hydrodynamics in central Pb+Pb collisions and find that the former's longitudinal flow profile responds more consistently to the fluid's gradients along the spacetime rapidity direction.
Exact scaling laws and the local structure of isotropic magnetohydrodynamic turbulence
Creators: name: Yousef, Tarek A.
name: Rincon, Francois
name: Schekochihin, Alexander A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: This paper examines the consistency of the exact scaling laws for isotropic MHD turbulence in numerical simulations with large magnetic Prandtl numbers Pm and with Pm=1. The exact laws are used to elucidate the structure of the magnetic and velocity fields. Despite the linear scaling of certain third-order correlation functions, the situation is not analogous to the case of Kolmogorov turbulence. The magnetic field is adequately described by a model of stripy (folded) field with direction reversals at the resistive scale. At currently available resolutions, the cascade of kinetic energy is short-circuited by the direct exchange of energy between the forcing-scale motions and the stripy magnetic fields. This nonlocal interaction is the defining feature of isotropic MHD turbulence.
description: 10 pages, 6 figures. Accepted for publication in Journal of Fluid Mechanics
High-temperature series for the bond-diluted Ising model in 3, 4 and 5 dimensions
Creators: name: Hellmund, Meik
name: Janke, Wolfhard
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: In order to study the influence of quenched disorder on second-order phase transitions, high-temperature series expansions of the \sus and the free energy are obtained for the quenched bond-diluted Ising model in $d = 3$--5 dimensions. They are analysed using different extrapolation methods tailored to the expected singularity behaviours. In $d = 4$ and 5 dimensions we confirm that the critical behaviour is governed by the pure fixed point up to dilutions near the geometric bond percolation threshold. The existence and form of logarithmic corrections for the pure Ising model in $d = 4$ is confirmed and our results for the critical behaviour of the diluted system are in agreement with the type of singularity predicted by renormalization group considerations. In three dimensions we find large crossover effects between the pure Ising, percolation and random fixed point. We estimate the critical exponent of the \sus to be $γ=1.305(5)$ at the random fixed point.
description: 16 pages, 10 figures
Infrared properties of Mg$_{1-x}$Al$_x($B$_{1-y}$C$_{y}$)$_2$ single crystals in the normal and superconducting state
Creators: name: Di Castro, D.
name: Ortolani, M.
name: Cappelluti, E.
name: Schade, U.
name: Zhigadlo, N. D.
name: Karpinski, J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The reflectivity $R (ω)$ of $ab$-oriented Mg$_{1-x}$Al$_x$(B$_{1-y }$C$_y$)$_2$ single crystals has been measured by means of infrared microspectroscopy for $1300
description: 12 pages, 9 figures
Η φύση της Δικαιοσύνης στην Πολιτεία, τον Πολιτικό και τους Νόμους του Πλάτωνα.:
Creators: name: Σταυράκη, Αλεξάνδρα Κωνσταντίνου
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Δικαιοσύνη
Πολιτεία
Πολιτικός
Νόμοι
Πλάτωνας
Justice
Republic
Politicus
Laws
Plato

description: Σκοπός της παρούσας εργασίας είναι να μελετήσει την έννοια της Δικαιοσύνης, όπως αυτή ορίζεται στους διαλόγους Πολιτεία, Πολιτικός και Νόμοι του Πλάτωνα. Από την επισκόπηση της ειδικής βιβλιογραφίας τονίζεται η διαφορετική μορφή που αποδίδει ο Πλάτωνας στην έννοια της Δικαιοσύνης σε κάθε έναν από τους διαλόγους του, λόγω της χρονολογικής απόστασης του ενός διαλόγου από τον άλλον. Η κύρια συνεισφορά της παρούσας εργασίας είναι διπλή. Πρώτον εισάγει και αναλύει την έννοια της Δικαιοσύνης στους τρεις διαφορετικούς διαλόγους του Πλάτωνα. Δεύτερον, συνδέει κάποια από τα στοιχεία που συνθέτουν την έννοια της Δικαιοσύνης με την σύγχρονη εποχή χάρη στην αντιπαραβολή τους με την Δίκαιη Κοινωνία του John Rawls και με την χρήση σύγχρονων κοινωνικοοικονομικών στοιχείων.
description: The purpose of this study is to identify the concept of Justice, as this concept is determined on Plato’s dialogues, namely the Republic of Plato, the Politicus and the Plato’s Laws. The literature review demonstrated that the concept of Justice is differentiated through the years that mediated between the composition of the three dialogues. The contribution of this study is twofold. First, it introduces and discusses the concept of Justice in the three Plato’s dialogues. Second, it associates some of the elements of the notion of the Justice with the Justice as Fairness of John’s Rawls and with the use of contemporary social and economic elements.