cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Mixed symmetry localized modes and breathers in binary mixtures of Bose-Einstein condensates in optical lattices
Creators: name: Cruz, H. A.
name: Brazhnyi, V. A.
name: Konotop, V. V.
name: Alfimov, G. L.
name: Salerno, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We study localized modes in binary mixtures of Bose-Einstein condensates embedded in one-dimensional optical lattices. We report a diversity of asymmetric modes and investigate their dynamics. We concentrate on the cases where one of the components is dominant, i.e. has much larger number of atoms than the other one, and where both components have the numbers of atoms of the same order but different symmetries. In the first case we propose a method of systematic obtaining the modes, considering the "small" component as bifurcating from the continuum spectrum. A generalization of this approach combined with the use of the symmetry of the coupled Gross-Pitaevskii equations allows obtaining breather modes, which are also presented.
description: 11 pages, 16 figures
Diffusion of CH$_4$ in amorphous solid water
Creators: name: Maté, Belén
name: Cazaux, Stephanie
name: Satorre, Miguel Angel
name: Molpeceres, Germán
name: Ortigoso, Juan
name: Millán, Carlos
name: Santonja, Carmina
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Context. The diffusion of volatile species on amorphous solid water ice affects the chemistry on dust grains in the interstellar medium as well as the trapping of gases enriching planetary atmospheres or present in cometary material. Aims. The aim of the work is to provide diffusion coefficients of CH$_4$ on amorphous solid water (ASW), and to understand how they are affected by the ASW structure. Methods. Ice mixtures of H$_2$O and CH$_4$ were grown in different conditions and the sublimation of CH$_4$ was monitored via infrared spectroscopy or via the mass loss of a cryogenic quartz crystal microbalance. Diffusion coefficients were obtained from the experimental data assuming the systems obey Fick's law of diffusion. Monte Carlo simulations modeled the different amorphous solid water ice structures investigated and were used to reproduce and interpret the experimental results. Results. Diffusion coefficients of methane on amorphous solid water have been measured to be between 10$^{-12}$ and 10$^{-13}$ cm$^2$ s$^{-1}$ for temperatures ranging between 42 K and 60 K. We showed that diffusion can differ by one order of magnitude depending on the morphology of amorphous solid water. The porosity within water ice, and the network created by pore coalescence, enhance the diffusion of species within the pores.The diffusion rates derived experimentally cannot be used in our Monte Carlo simulations to reproduce the measurements. Conclusions. We conclude that Fick's law can be used to describe diffusion at the macroscopic scale, while Monte Carlo simulations describe the microscopic scale where trapping of species in the ices (and their movement) is considered.
description: 17 pages, 15 figures
Causes and Effects of the Journalist Job-Burnout
Creators: name: Νταλαμπίρα, Ελίνα Χρήστου
Publisher: name: Aristotle University of Thessaloniki
Year: 2017
Subjects: Επαγγελματική εξουθένωση
Δημοσιογραφία
Εργασιακό στρες
Burnout
Journalism
Work-related stress

description: The present study aims to provide an empirical research relating to the experience of burnout in journalists of various specialties and mediums. The methodology adopted contains three main elements: sampling the literature, screening the literature, and extracting data. Results indicate that there is a very interesting transition in the role of journalism through the years of crisis. Women are more vulnerable than men in burnout, while younger journalists are keen on leaving the profession sooner than the older ones due to the tense working conditions and stress. The medium with the less degree of depersonalization remains the radio because maybe we talk about the technological advancements of the western world and civilization, while things in third world countries are adverse. People have no so many choices for receiving information. What is lacking is consideration of other role groups to broadcast news, such as camera-operators, rethinking of the journalistic contribution and organizational behavior management. A range of methodological and theoretical issues and future areas of research are discussed.
description: Σκοπός της διατριβής ήταν η μελέτη της επαγγελματικής εξουθένωσης στο χώρο της δημοσιογραφίας. Δόθηκε ιδιαίτερη έμφαση στην περίπτωση της Ελλάδας ιδιαίτερα κατά τη διάρκεια της οικονομικής και θεσμικής κρίσης. Διαχωρίσαμε τις έννοιες εργασιακό στρες και επαγγελματική εξουθένωση. Εξετάσαμε τις αιτίες και τις συνέπειες του φαινομένου μέσω μιας βιβλιογραφικής ανασκόπησης καθώς και τα θεωρητικά μοντέλα που αφορούν την επαγγελματική εξουθένωση. Στη συνέχεια χρησιμοποιήσαμε ένα ερωτηματολόγιο το οποίο μοιράστηκε σε Έλληνες δημσιογράφους και απαντήθηκε επιτυχώς χωρίς καμία απώλεια. Έτσι προέκυψε και ένα άλλο πολύ σημαντικό θέμα αυτό της οργανωσιακής συμπεριφοράς. Σαφέστατα ο διαχωρισμός μεταξύ προσωπικής και επαγγελματικής ζωής για άνδρες και γυναίκες αντίστοιχα μας απασχόλησε όπως και το οργανωσιακό κόστος που μπορεί να επιφέρει η απόδοση των εργαζομένων.
The Search for an Atmospheric Signature of the Transiting Exoplanet HD 149026b
Creators: name: Bozorgnia, Nassim
name: Fortney, Jonathan J.
name: McCarthy, Chris
name: Fischer, Debra A.
name: Marcy, Geoffrey W.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: HD 149026b is a short-period, Saturn-mass planet that transits a metal-rich star. The planet's radius, determined by photometry, is remarkably small compared to other known transiting planets, with a heavy-element core that apparently comprises ~70% of the total planet mass. Time-series spectra were obtained at Keck before and during transit in order to model the Rossiter-McLaughlin effect. Here we make use of these observations to carry out a differential comparison of spectra obtained in and out of transit to search for signatures of neutral atomic lithium and potassium from the planet atmosphere. No signal was detected at the 2% level; we therefore place upper limits on the column density of these atoms.
description: 8 pages, 10 figures, 2 tables
Synthesis of polystyrene / acrolein latexes and their surface characterization
Creators: name: Le Dissez, Corinne
Publisher: name: University of British Columbia
Year: 2009

description: A semi-continuous synthesis of polystyrene/acrolein latex was carried out. The optimum addition time of acrolein monomer was determined to be 10 hours after addition of the initiator, giving a monodisperse polystyrene latex with aldehyde on the surface. A DNPH assay was used to assay the aldehyde group in the latex suspension; it was specifically a surface assay. It successfully detected aldehydes at concentrations above 1 x 10⁻⁶ mol/g but was limited at high surface concentrations of aldehyde probably due to the steric hindrance. Quantitative agreement with respect to surface concentration of aldehyde groups was obtained using freshly solubilized NaBT 4 reduction in a radiochemical assay. NMR was used to assay aldehydes present in dissolved latex and the same result as for the DNPH assay was obtained. NMR provided information on the environment of the surface aldehydes, the chemical shift showing the possible presence of polyacrolein chains on the latex with the seeded reaction. This was an important observation as the polyacrolein blocks are not favorable for the grafting reactions to be carried out later in this project. XPS provided strong evidence that aldehyde functions were present on the latex surface, were reactive with DNPH and were reduced by NaBH₄. The XPS spectra obtained were those expected based on the surface chemistry anticipated and no unexpected groups were detected.
Dimension of the isometry group in three-dimensional Riemannian spaces
Creators: name: Ferrando, Joan Josep
name: Sáez, Juan Antonio
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The necessary and sufficient conditions for a three-dimensional Riemannian metric to admit a group of isometries of dimension $r$ acting on s-dimensional orbits are obtained. These conditions are Intrinsic, Deductive, Explicit and ALgorithmic and they offer an IDEAL labeling that improves previously known invariant studies.
description: 8 pages, 1 figure
The JFP2017 Computational theory of verified policy advice: an overview
Creators: name: Botta, Nicola
name: Brede, Nuria
name: Crucifix, Michel
name: Martínez Montero, Marina
name: Jansson, Patrik
name: Ionescu, Cezar
Publisher: name: Zenodo
Year: 2021
Subjects: climate science
program verification
policy advice
overview

description: Slides of my talk at the TiPES Theme 4 (Data and decisions) workshop from Oct. 13 2020
Matterwaves, Matterons, and the Atomtronic Transistor Oscillator
Creators: name: Anderson, Dana Z.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Applied Physics (physics.app-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: A self-consistent theoretical treatment of a triple-well atomtronic transistor circuit reveals the mechanism of gain, conditions of oscillation, and properties of the subsequent coherent matterwaves emitted by the circuit. A Bose-condensed reservoir of atoms in a large source well provides a chemical potential that drives circuit dynamics. The theory is based on the ansatz that a condensate arises in the transistor gate well as a displaced ground state, that is, one that undergoes dipole oscillation in the well. That gate atoms remain condensed and oscillating is shown to be a consequence of the cooling induced by the emission of a matterwave into the vacuum. Key circuit parameters such as the transistor transconductance and output current are derived by transitioning to a classical equivalent circuit model. Voltage-like and current-like matterwave circuit wave fields are introduced in analogy with microwave circuits, as well as an impedance relationship between the two. This leads to a new notion of a classical coherent matterwave that is the dual of a coherent electromagnetic wave and which is distinct from a deBroglie matterwave associated with cold atoms. Subjecting the emitted atom flux to an atomic potential that will reduce the deBroglie wavelength, for example, will increase the classical matterwave wavelength. Quantization of the classical matterwave fields leads to the dual of the photon that is identified not as an atom but as something else, which is here dubbed a "matteron".
description: 13 Pages, 9 figures
Structure formation in the quasispherical Szekeres model
Creators: name: Bolejko, Krzysztof
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Structure formation in the Szekeres model is investigated. Since the Szekeres model is an inhomogeneous model with no symmetries, it is possible to examine the interaction of neighboring structures and its impact on the growth of a density contrast. It has been found that the mass flow from voids to clusters enhances the growth of the density contrast. In the model presented here, the growth of the density contrast is almost 8 times faster than in the linear approach.
description: 11 pages, 14 figures; changes after referee comments; accepted for publication in Physical Review D15
Ανωνύμου Προλεγόμενα εις την Φιλοσοφίαν του Πλάτωνος
Creators: name: Εμμανουηλίδης Χρήστος Εμμανουήλ
Publisher: name: Aristotle University of Thessaloniki
Year: 2017
Subjects: Πλάτων
Ανωνύμου Προλεγόμενα
Νεοπλατωνισμός
Plato
Anonymous Prolegomena
Neoplatonism

description: Το έργο αυτό του ύστερου Νεοπλατωνισμού πιθανολογείται ότι γράφηκε στην Αλεξάνδρεια τον 6ο αιώνα μ.Χ. Ο συγγραφέας μας είναι άγνωστος αλλά προφανώς πρόκειται για κάποιον Νεοπλατωνιστή δάσκαλο της πλατωνικής φιλοσοφίας. Η συγγραφή απευθύνεται σε σπουδαστές φιλοσοφίας σε κάποιο ενδιάμεσο στάδιο των σπουδών τους και αποσκοπεί να τους εισάγει στην πλατωνική φιλοσοφία. Το πρώτο και εκτεταμένο μέρος του έργου περιέχει μια εγκωμιαστική βιογραφία του Πλάτωνα όπου συνδυάζονται πραγματικά γεγονότα με θρύλους που τεκμηριώνουν την θεϊκή του φύση. Στην συνέχεια, σε εννέα διαδοχικά κεφάλαια αναλύονται με οργανωμένο και μεθοδικό τρόπο τα διάφορα ερωτήματα σχετικά με το πλατωνικό έργο. Μεγάλη προσπάθεια καταβάλλει ο συγγραφέας για να αποδείξει ότι η πλατωνική φιλοσοφία υπερέχει κάθε προηγούμενου ή επόμενου φιλοσοφικού συστήματος αντιπαραβάλλοντας τα κύρια δόγματα των άλλων θεωριών και δείχνοντας πως τα ξεπερνά ο Πλάτωνας. Ιδιαίτερη έμφαση δίδεται Anonymous στο να διαφοροποιηθεί ο Πλάτων από τους Σκεπτικούς οι οποίο και αυτοί διατείνονται ότι είναι συνεχιστές της Σωκρατικής φιλοσοφίας. Η διαπραγμάτευση ερωτημάτων όπως γιατί έγραψε σε διαλογική μορφή, πώς να κατανοούμε την κεντρική ιδέα κάθε διαλόγου και με πια σειρά πρέπει να μελετώνται τα πλατωνικά έργα πέρα από το φιλολογικό ενδιαφέρον διαφωτίζει για τον τρόπο πρόσληψης του πλατωνικού έργου κατά την ύστερη αρχαιότητα. Η εργασία περιλαμβάνει μια εκτεταμένη εισαγωγή και την πρώτη νεοελληνική απόδοση όλου του έργου.
description: This neoplatonic work belongs to latter antiquity era; it is presumed to have been composed in Alexandria in the 6th century ad. The unidentified writer is undoubtedly a teacher of philosophy in a neoplatonic school of his time. His writing seems to be addressed to philosophy students of a middle level. Presumably his audience has been introduced to elements of logic and aristotelean categories and are ready to be introduced to the “higher: platonic philosophy. The first part is dedicated to an encomiastic biography of the philosopher aiming at educating but also at inciting awe and eagerness. Much effort is given to arguments proving the superiority of Plato compared to philosophical schools before and after his time, with particular emphasis in clearly distinguishing him from the Sceptics aho also claimed to be followers of the Socratic school of thought. Issues such as the reasons for the form of dialogue Plato gave to most of his works, how to analyze and identify the gist of each dialogue, in which order Plato’s dialogues ought to be studied are discussed and provide us with a good understanding of how Plato was perceived during latter Antiquity. The thesis includes an ample introduction and a translation of the whole work in modern Greek.
Measurement of the production cross-section of positive pions in the collision of 8.9 GeV/c protons on beryllium
Creators: name: HARP Collaboration
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The double-differential production cross-section of positive pions, $d^2σ^{π^{+}}/dpdΩ$, measured in the HARP experiment is presented. The incident particles are 8.9 GeV/c protons directed onto a beryllium target with a nominal thickness of 5% of a nuclear interaction length. The measured cross-section has a direct impact on the prediction of neutrino fluxes for the MiniBooNE and SciBooNE experiments at Fermilab. After cuts, 13 million protons on target produced about 96,000 reconstructed secondary tracks which were used in this analysis. Cross-section results are presented in the kinematic range 0.75 GeV/c < $p_π$ < 6.5 GeV/c and 30 mrad < $θ_π$ < 210 mrad in the laboratory frame.
description: 39 pages, 21 figures. Version accepted for publication by Eur. Phys. J. C
Energy stability analysis of turbulent incompressible flow based on the triple decomposition of the velocity gradient tensor
Creators: name: Hoffman, Johan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Numerical Analysis (math.NA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: In the context of flow visualization a triple decomposition of the velocity gradient into irrotational straining flow, shear flow and rigid body rotational flow was proposed by Kolar in 2007 [V. Kolar, International journal of heat and fluid flow, 28, 638, (2007)], which has recently received renewed interest. The triple decomposition opens for a refined energy stability analysis of the Navier-Stokes equations, with implications for the mathematical analysis of the structure, computability and regularity of turbulent flow. We here perform an energy stability analysis of turbulent incompressible flow, which suggests a scenario where at macroscopic scales any exponentially unstable irrotational straining flow structures rapidly evolve towards linearly unstable shear flow and stable rigid body rotational flow. This scenario does not rule out irrotational straining flow close to the Kolmogorov microscales, since there viscous dissipation stabilizes the unstable flow structures. In contrast to worst case energy stability estimates, this refined stability analysis reflects the existence of stable flow structures in turbulence over extended time.
description: 7 pages. The following article has been submitted to Physics of Fluids
Gamow-Teller transitions of neutron-rich $N=82,81$ nuclei by shell-model calculations
Creators: name: Shimizu, Noritaka
name: Togashi, Tomoaki
name: Utsuno, Yutaka
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: $β$-decay half-lives of neutron-rich nuclei around $N=82$ are key data to understand the $r$-process nucleosynthesis. We performed large-scale shell-model calculations in this region using a newly constructed shell-model Hamiltonian, and successfully described the low-lying spectra and half-lives of neutron-rich $N=82$ and $N=81$ isotones with $Z=42-49$ in a unified way. We found that their Gamow-Teller strength distributions have a peak in the low-excitation energies, which significantly contributes to the half-lives. This peak, dominated by $ν0g_{7/2} \to π0g_{9/2}$ transitions, is enhanced on the proton deficient side because the Pauli-blocking effect caused by occupying the valence proton $0g_{9/2}$ orbit is weakened.
$D_{sJ}(2860)$ resonance and the $s_\ell^P={5\over 2}^-$ $c \bar s$ ($c \bar q$) doublet
Creators: name: Colangelo, P.
name: De Fazio, F.
name: Nicotri, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We analyze the recently discovered $D_{sJ}(2860)$ meson using arguments based on the heavy quark expansion together with the experimental observations. We consider the possible quantum number assignments, arguing that the interpretation of the meson as the $J^P=3^-$ $c \bar s$ state is favoured.
description: LaTeX, 9 pages, 1 figure - published version
Dispersion relation analysis of the radiative corrections to $g_A$ in the neutron $β$-decay
Creators: name: Gorchtein, Mikhail
name: Seng, Chien-Yeah
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present the first and complete dispersion relation analysis of the inner radiative corrections to the axial coupling constant $g_A$ in the neutron $β$-decay. Using experimental inputs from the elastic form factors and the spin-dependent structure function $g_1$, we determine the contribution from the $γW$-box diagram to a precision better than $10^{-4}$. Our calculation indicates that the inner radiative corrections to the Fermi and the Gamow-Teller matrix element in the neutron $β$-decay are almost identical, i.e. the ratio $λ=g_A/g_V$ is almost unrenormalized. With this result, we predict the bare axial coupling constant to be {$\mathring{g}_A=-1.2754(13)_\mathrm{exp}(2)_\mathrm{RC}$} based on the PDG average $λ=-1.2756(13)$
description: Revised manuscript
On Approximation of the Eigenvalues of Perturbed Periodic Schrodinger Operators
Creators: name: Boulton, Lyonell
name: Levitin, Michael
Publisher: name: arXiv
Year: 2007
Subjects: subject: Spectral Theory (math.SP)
subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 47A75; 65J10

description: This paper addresses the problem of computing the eigenvalues lying in the gaps of the essential spectrum of a periodic Schrodinger operator perturbed by a fast decreasing potential. We use a recently developed technique, the so called quadratic projection method, in order to achieve convergence free from spectral pollution. We describe the theoretical foundations of the method in detail, and illustrate its effectiveness by several examples.
description: 17 pages, 2 tables and 2 figures
Experimental Measures of Affine and Non-affine Deformation in Granular Shear
Creators: name: Utter, Brian
name: Behringer, R. P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Through 2D granular Couette flow experiments, we probe failure and deformation of disordered solids under shear. Shear produces smooth affine deformations in such a solid and also irresversible so-called non-affine particle displacements. We examine both processes. We show that the non-affine part is associated with diffusion, and also can be used to define a granular temperature. Distributions for single particle non-affine displacements, $\dri$, satisfy $P_1(\dri) \propto \exp [-|\dri/Δr|^α]$ ($α\stackrel{
description: 4 pages, 5 figures
Examining the impact of age on usage of mobile phones in language learning
Creators: name: Μούτσιου, Φωτεινή Παναγιώτη
Publisher: name: Aristotle University of Thessaloniki
Year: 2017
Subjects: Γλωσσική εκμάθηση με κινητές συσκευές
Ηλικία
Εφαρμογές
MALL
Age
Apps

description: Η εκμάθηση γλωσσών με τη βοήθεια κινητών συσκευών αυξάνεται σε δημοτικότητα τα τελευταία χρόνια λόγω της ευρείας χρήσης του κινητού τηλεφώνου. Παρόλο που έχουν διερευνηθεί διάφορες πτυχές της, εξακολουθούν να υπάρχουν μερικά ενδιαφέροντα προβλήματα σχετικά με αυτή που πρέπει να αντιμετωπιστούν, για παράδειγμα, η επίδραση της ηλικίας των μαθητών. Αυτή η μελέτη επικεντρώνεται σε δύο ηλικιακές ομάδες, τους εφήβους και τους ενήλικες, και εξετάζει τι και πώς μαθαίνουν στις κινητές τους συσκευές, καθώς επίσης συζητά την επίδραση που έχει η ηλικία των μαθητών στη στάση τους απέναντι στην εκμάθηση γλωσσών με τη βοήθεια κινητών συσκευών. Για να γίνει αυτό, μια ομάδα εφήβων και μια ομάδα ενηλίκων μαθητών κατέβασαν και χρησιμοποίησαν εφαρμογές για κινητά για μια περίοδο 11 εβδομάδων. Τα δεδομένα συλλέχθηκαν μέσω ενός αρχικού ερωτηματολογίου, ημερολογίων μάθησης, και ενός τελικού ερωτηματολογίου. Τα ευρήματα αποκάλυψαν ότι υπάρχουν διαφορές ως προς το τι και πώς αυτές οι δύο ηλικιακές ομάδες μαθαίνουν στις κινητές τους συσκευές και ότι η ηλικία επηρεάζει τη στάση των μαθητών απέναντι στην εκμάθηση γλωσσών με τη βοήθεια κινητών συσκευών
description: Mobile-assisted language learning (MALL) has been growing in popularity in the last years on account of the widespread use of the mobile phone. Although various aspects of it have been investigated, there are still some interesting and relevant problems to be addressed, for example, the effect of learner age. This study focuses on two age groups, adolescents and adults, and examines what and how they learn on their mobile devices as well as discusses the effect learner age has on attitude to MALL. In order to do this, a cohort of adolescent and a cohort of adult learners downloaded and used mobile apps for a period of 11 weeks. Data were collected by means of a pre-treatment questionnaire, learning journals, and a post-treatment questionnaire. The findings revealed that there are differences in what and how these two age groups learn on their mobile devices, and that age has an effect on learner attitude to MALL
Preferential Temporal Difference Learning
Creators: name: Anand, Nishanth
name: Precup, Doina
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Temporal-Difference (TD) learning is a general and very useful tool for estimating the value function of a given policy, which in turn is required to find good policies. Generally speaking, TD learning updates states whenever they are visited. When the agent lands in a state, its value can be used to compute the TD-error, which is then propagated to other states. However, it may be interesting, when computing updates, to take into account other information than whether a state is visited or not. For example, some states might be more important than others (such as states which are frequently seen in a successful trajectory). Or, some states might have unreliable value estimates (for example, due to partial observability or lack of data), making their values less desirable as targets. We propose an approach to re-weighting states used in TD updates, both when they are the input and when they provide the target for the update. We prove that our approach converges with linear function approximation and illustrate its desirable empirical behaviour compared to other TD-style methods.
description: Accepted at the 38th International Conference on Machine Learning (ICML, 2021)
The flavor-changing top-charm quark production in the littlest Higgs model with T parity at the ILC
Creators: name: Wang, Xuelei
name: Jin, Huiling
name: Zhang, Yanju
name: Xi, Yanhui
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: With high luminosity and energy at the ILC and clean SM backgrounds, the top-charm production at the ILC should have powerful potential to probe new physics. The littlest Higgs model with discrete symmetry named "T-parity"(LHT) is one of the most promising new physics models. In this paper, we study the FC processes $e^+e^-(γγ)\to t\bar{c}$ at the ILC in the LHT model. Our study shows that the LHT model can make a significant contribution to these processes. When the masses of mirror quarks become large, these two processes are accessible at the ILC. So the top-charm production at the ILC provides a unique way to study the properties of the FC couplings in the LHT model and furthermore test the model.
description: 19 pages, 5 figures
Correcting Doppler Shifts in He II 30.38 nm Line by Using the EVE and AIA data from Solar Dynamics Observatory
Creators: name: Cheng, Zhixun
name: Wang, Yuming
name: Liu, Rui
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The Extreme-ultraviolet Variability Experiment (EVE) onboard the Solar Dynamics Observatory (SDO) detects the solar EUV spectra with high temporal cadence and spectral resolution. The wavelength shifts of emission lines provide key information of the dynamics of the Sun. However, some of EVE spectral observations are influenced by the non-uniformly distributed irradiance on the Sun, which may prevent us from correctly understanding the physical processes happened in the solar corona. Here, based on the only published on-orbit calibration data of EVE He II 30.38 nm line on 27 Jan 2011 (Chamberlin, 2016), we develop a method to correct the He II 30.38 nm line by using AIA 304 imaging data. This correction method is then applied to EVE He II 30.38 nm data from 29 Oct 2010 to 3 Mar 2011 to study the Doppler oscillations of the solar He II 30.38 nm line, in which we show that the half-month periodic Doppler oscillation is caused by non-uniformly distributed irradiance mainly due to the presence of active regions. Other EVE coronal lines also present similar Doppler oscillations, suggesting that an appropriate correction must be implemented before interpret the oscillation phenomena appearing in these lines.
A Criterion for the Onset of Chaos in Compact, Eccentric Multiplanet Systems
Creators: name: Tamayo, Daniel
name: Murray, Norman
name: Tremaine, Scott
name: Winn, Joshua
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We derive a semi-analytic criterion for the presence of chaos in compact, eccentric multiplanet systems. Beyond a minimum semimajor-axis separation, below which the dynamics are chaotic at all eccentricities, we show that (i) the onset of chaos is determined by the overlap of two-body mean motion resonances (MMRs), like it is in two-planet systems; (ii) secular evolution causes the MMR widths to expand and contract adiabatically, so that the chaotic boundary is established where MMRs overlap at their greatest width. For closely spaced two-planet systems, a near-symmetry strongly suppresses this secular modulation, explaining why the chaotic boundaries for two-planet systems are qualitatively different from cases with more than two planets. We use these results to derive an improved angular-momentum-deficit (AMD) stability criterion, i.e., the critical system AMD below which stability should be guaranteed. This introduces an additional factor to the expression from Laskar and Petit (2017) that is exponential in the interplanetary separations, which corrects the AMD threshold toward lower eccentricities by a factor of several for tightly packed configurations. We make routines for evaluating the chaotic boundary available to the community through the open-source SPOCK package.
description: Accepted in AJ. Routines for estimating whether compact planetary configurations are chaotic, together with example notebooks are available as part of the SPOCK package: https://github.com/dtamayo/spock
Development of a laser ablation quadrupole ion trap mass spectrometer for direct spectrometry of solid samples
Creators: name: Gill, Christopher George
Publisher: name: University of British Columbia
Year: 2009

description: Elemental analysis of solid samples often involves a dissolution step prior to analysis, which can introduce contamination and result in further dilution of trace analytes. Methods of direct solid analysis obviate this step, and can provide compositional information for solid materials. To achieve very low detection limits for analytes in solid samples requires special methodology. One way to achieve lower limits of detection is to increase the observation time for an analyte. Quadrupole ion traps have demonstrated single ion detection using laser based ion detection methods, making the combination of laser ablation for direct solid sampling and quadrupole ion trap mass spectrometry a logical choice for ultra-trace (sub-femtogram) analysis. This thesis examines the use of laser ablation coupled with quadrupole ion trap mass spectrometry as a potential analytical method for ultra-trace direct solid multielemental mass spectrometry. This thesis develops an analytical method for direct solid mass spectrometry, called Laser Ablation Ion Trap Mass Spectrometry (LAITMS). Through a series of investigations, a hybrid mass spectrometer has evolved which embodies many characteristics that are desirable for LAITMS analysis. The function of this new spectrometer was subsequently investigated by a series of parametric studies to determine optimum conditions for it’s operation as a simple mass spectrometer, capable of direct solid analysis. Parameters considered included laser irradiance & wavelength, ion storage field characteristics and sample surface quality. The use of modified hyperbolic electrodes as well as cylindrical electrode configurations has been examined. Selective ionization schemes for analytes in solid samples has been investigated by a two-color LAITMS experiment. The effect of synchronizing laser ablation with the phase of the ion storage field has also been examined. The present LAITMS spectrometer has demonstrated picogram detection limits for analytes present in samples of stainless steel. Future laser induced fluorescence ion detection schemes should realize much lower detection limits.
Communication models with distributed transmission rates and buffer sizes
Creators: name: Arrowsmith, David
name: di Bernardo, Mario
name: Sorrentino, Francesco
Publisher: name: arXiv
Year: 2006
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The paper is concerned with the interplay between network structure and traffic dynamics in a communications network, from the viewpoint of end-to-end performance of packet transfer. We use a model of network generation that allows the transition from random to scale-free networks. Specifically, we are able to consider three different topologycal types of networks: (a) random; (b) scale-free with γ=3; (c) scale free with γ=2. We also use an LRD traffic generator in order to reproduce the fractal behavior that is observed in real world data communication. The issue is addressed of how the traffic behavior on the network is influenced by the variable factors of the transmission rates and queue length restrictions at the network vertices. We show that these factors can induce drastic changes in the throughput and delivery time of network performance and are able to counter-balance some undesirable effects due to the topology.
description: 4 pages, 5 figures, IEEE Symposium on Circuits and Systems, Island of Kos, Greece, 2006
On the dipole straylight contamination in spinning space missions dedicated to CMB anisotropy
Creators: name: Burigana, Carlo
name: Gruppuso, Alessandro
name: Finelli, Fabio
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present an analysis of the dipole straylight contamination (DSC) for spinning space-missions designed to measure CMB anisotropies. Although this work is mainly devoted to the {\sc Planck} project, it is relatively general and allows to focus on the most relevant DSC implications. We first study a simple analytical model for the DSC in which the pointing direction of the main spillover can be assumed parallel or not to the spacecraft spin axis direction and compute the time ordered data and map. The map is then analysed paying particular attention to the DSC of the low multipole coefficients of the map. Through dedicated numerical simulations we verify the analytical results and extend the analysis to higher multipoles and to more complex (and realistic) cases by relaxing some of the simple assumptions adopted in the analytical approach. We find that the systematic effect averages out in an even number of surveys, except for a contamination of the dipole itself that survives when spin axis and spillover directions are not parallel and for a contamination of the other multipoles in the case of complex scanning strategies. In particular, the observed quadrupole can be affected by the DSC in an odd number of surveys or in the presence of survey uncompleteness or over-completeness. Various aspects relevant in CMB space projects (such as implications for calibration, impact on polarization measurements, accuracy requirement in the far beam knowledge for data analysis applications, scanning strategy dependence) are discussed.
description: 21 pages, 13 Figures, 1 Table. To appear in MNRAS. Accepted 2006 July 13. Received 2006 July 13; in original form 2006 June 7. This work has been done in the framework of the Planck LFI activities
Comparing Brane Inflation to WMAP
Creators: name: Bean, Rachel
name: Shandera, Sarah E.
name: Tye, S. H. Henry
name: Xu, Jiajun
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We compare the simplest realistic brane inflationary model to recent cosmological data, including WMAP 3-year cosmic microwave background (CMB) results, Sloan Digital Sky Survey luminous red galaxies (SDSS LRG) power spectrum data and Supernovae Legacy Survey (SNLS) Type 1a supernovae distance measures. Here, the inflaton is simply the position of a $D3$-brane which is moving towards a $\bar{D}3$-brane sitting at the bottom of a throat (a warped, deformed conifold) in the flux compactified bulk in Type IIB string theory. The analysis includes both the usual slow-roll scenario and the Dirac-Born-Infeld scenario of slow but relativistic rolling. Requiring that the throat is inside the bulk greatly restricts the allowed parameter space. We discuss possible scenarios in which large tensor mode and/or non-Gaussianity may emerge. Here, the properties of a large tensor mode deviate from that in the usual slow-roll scenario, providing a possible stringy signature. Overall, within the brane inflationary scenario, the cosmological data is providing information about the properties of the compactification of the extra dimensions.
description: 45 pages 11 figures
Dirac plus Nambu Monopoles in the Standard Model
Creators: name: Lazarides, George
name: Shafi, Qaisar
name: Vachaspati, Tanmay
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We show how in the standard electroweak model three $SU(2)_L$ Nambu monopoles, each carrying electromagnetic (EM) and Z- magnetic fluxes, can merge (through Z-strings) with a single $U(1)_Y$ Dirac monopole to yield a composite monopole that only carries EM magnetic flux. Compatibility with the Dirac quantization condition requires this composite monopole to carry six quanta ($12 π/e$) of magnetic charge, independent of the electroweak mixing angle $θ_w$. The Dirac monopole is not regular at the origin and the energy of the composite monopole is therefore divergent. We discuss how this problem is cured by embedding $U(1)_Y$ in a grand unified group such as $SU(5)$. A second composite configuration with only one Nambu monopole and a colored $U(1)_Y$ Dirac monopole that has minimal EM charge of $4π/e$ is also described. Finally, there exists a configuration with an EM charge of $8π/e$ as well as screened color magnetic charge.
description: 4 pages, 2 figures; published (PRD) version
Performance analysis of continuous-time solvers for quantum impurity models
Creators: name: Gull, Emanuel
name: Werner, Philipp
name: Millis, Andrew J.
name: Troyer, Matthias
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Impurity solvers play an essential role in the numerical investigation of strongly correlated electrons systems within the "dynamical mean field" approximation. Recently, a new class of continuous-time solvers has been developed, based on a diagrammatic expansion of the partition function in either the interactions or the impurity-bath hybridization. We investigate the performance of these two complementary approaches and compare them to the well-established Hirsch-Fye method. The results show that the continuous-time methods, and in particular the version which expands in the hybridization, provide substantial gains in computational efficiency.
Elicitation session: Associative, progressive, plural, extensions in verb-verb constructions, prepositions n vs. no
Creators: name: Diouf, Maryama
name: Merrill, John
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: srr

description: 2 WAV files. Session conducted monolingually in Sereer. The associative is -(y)iin, the progressive suffix is -(y)ii, and the plural is (y)oo.
Lorentz-violating electrodynamics and the cosmic microwave background
Creators: name: Kostelecky, Alan
name: Mewes, Matthew
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Possible Lorentz-violating effects in the cosmic microwave background are studied. We provide a systematic classification of renormalizable and nonrenormalizable operators for Lorentz violation in electrodynamics and use polarimetric observations to search for the associated violations.
description: 4 pages two-column REVTeX, accepted in Physical Review Letters
Transport of Forced Quantum Motors in the Strong Friction Limit
Creators: name: Machura, Lukasz
name: Luczka, Jerzy
name: Talkner, Peter
name: Hänggi, Peter
Publisher: name: arXiv
Year: 2006
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The directed transport of an overdamped Brownian motor moving in a spatially periodic potential that lacks reflection symmetry (i.e. a ratchet potential) is studied when driven by thermal and dichotomic nonequilibrium noise in the presence of an external, constant load force. We consider both, the classical and the quantum tunneling assisted regimes. The current-load characteristics are investigated as a function of the system parameters like the load force, the temperature and the amplitude strength of the applied two-state noise.
description: 10 pages, 5 figures, Presented at the Marian Smoluchowski Symposium on Statistical Physics, Krakow, Poland, May 14-17, 2006; Acta Physica Polonica B (in press) 2007
Classical spin dynamics based on SU($N$) coherent states
Creators: name: Zhang, Hao
name: Batista, Cristian D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We introduce a classical limit of the dynamics of quantum spin systems based on coherent states of SU($N$), where $N$ is the dimension of the local Hilbert space. This approach, that generalizes the well-known Landau-Lifshitz dynamics from SU(2) to SU($N$), provides a better approximation to the exact quantum dynamics for a large class of realistic spin Hamiltonians, including $S \geq 1$ systems with large single-ion anisotropy and weakly-coupled multi-spin units, such as dimers or trimers. We illustrate this idea by comparing the spin structure factors of a single-ion $S=1$ model that are obtained with the SU(2) and SU(3) classical spin dynamics against the exact solution.
description: 12 pages, 2 figures
On a Possible Mechanism of the Production of Pentaquark States $Θ(ud\bar{s}ud)$
Creators: name: Baranov, S. P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A new mechanism of the production of hypothetical $Θ(ud\bar{s}ud)^+$ pentaquark state is suggested. The considered mechanism is based on the exchange by exotic Regge trajectories in the $t$ channel. It is shown that the momentum distributions of $Θ^+$ baryons can differ significantly from the ones of the ordinary hyperons.
description: 5 pages, 2 figures
Critical spin liquid at 1/3 magnetization in a spin-1/2 triangular antiferromagnet
Creators: name: Alicea, Jason
name: Fisher, Matthew P. A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Although magnetically ordered at low temperatures, the spin-1/2 triangular antiferromagnet Cs_2CuCl_4 exhibits remarkable spin dynamics that strongly suggest proximity to a spin liquid phase. Here we address the question of whether a proximate spin liquid may also occur in an applied magnetic field, leaving a similar imprint on the dynamical spin correlations of this material. Specifically, we explore a spatially anisotropic Heisenberg spin-1/2 triangular antiferromagnet at 1/3 magnetization from a dual vortex perspective, and indeed find a new ``critical'' spin liquid phase described by QED3 with an emergent SU(6) symmetry. A number of nontrivial predictions are given for the dynamical spin structure factor in this ``algebraic vortex liquid'' phase, which can be tested experimentally via inelastic neutron scattering. We also discuss how the well-studied ``up-up-down'' magnetization plateaus can be captured within our approach, and further predict the existence of a stable gapless solid phase in a weakly ordered up-up-down state. Finally, we predict several anomalous ``roton'' minima in the excitation spectrum in the regime of lattice anisotropy where the canted Neel state appears.
description: 5 pages, 2 figures; expanded intro & discussion of theory; minor correction to structure factor
On Existence of Ground States in the Spin Boson Model
Creators: name: Hasler, David
name: Hinrichs, Benjamin
name: Siebert, Oliver
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: Spectral Theory (math.SP)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We show the existence of ground states in the massless spin boson model without any infrared regularization. Our proof is non-perturbative and relies on a compactness argument. It works for arbitrary values of the coupling constant under the hypothesis that the second derivative of the ground state energy as a function of a constant external magnetic field is bounded.
description: 14 pages
The Role of 5-quark Components on the Nucleon Form Factors
Creators: name: Li, Q. B.
name: Riska, D. O.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The covariant quark model is shown to allow a phenomenological description of the neutron electric form factor, G_E^n(Q^2), in the impulse approximation, provided that the wave function contains minor (~ 3 %) admixtures of the lowest sea-quark configurations. While that form factor is not very sensitive to whether the \bar q in the qqqq\bar q component is in the P-state or in the S-state, the calculated nucleon magnetic form factors are much closer to the empirical values in the case of the former configuration. In the case of the electric form factor of the proton, G_E^p(Q^2), a zero appears in the impulse approximation close to 9 GeV^2, when the \bar q is in the P-state. That configuration, which may be interpreted as a pion loop ("cloud") fluctuation, also leads to a clearly better description of the nucleon magnetic moments. When the amplitude of the sea-quark admixtures are set so as to describe the electric form factor of the neutron, the qqqq\bar q admixtures have the phenomenologically desirable feature, that the electric form factor of the proton falls at a more rapid rate with momentum transfer than the magnetic form factor.
description: To appear in Nuclear Physics A