cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). XIV. A Candidate Type-II Quasar at z=6.1292
Creators: name: Onoue, Masafusa
name: Matsuoka, Yoshiki
name: Kashikawa, Nobunari
name: Strauss, Michael A.
name: Iwasawa, Kazushi
name: Izumi, Takuma
name: Nagao, Tohru
name: Asami, Naoko
name: Fujimoto, Seiji
name: Harikane, Yuichi
name: Hashimoto, Takuya
name: Imanishi, Masatoshi
name: Lee, Chien-Hsiu
name: Takatoshi
name: Shibuya
name: Toba, Yoshiki
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present deep Keck/MOSFIRE near-infrared spectroscopy of a strong Lyman alpha emitting source at z=6.1292, HSC J142331.71-001809.1, which was discovered by the SHELLQS program from imaging data of the Subaru Hyper Suprime-Cam (HSC) survey. This source is one of five objects that show unresolved (<230 km s-1) and prominent (>10^44 erg s-1) Lyman alpha emission lines at absolute 1450 angstrom continuum magnitudes of M1450~-22 mag. Its rest-frame Lyman alpha equivalent width (EW) is 370+/-30 angstrom. In the 2 hour Keck/MOSFIRE spectrum in Y band, the high-ionization CIV 1548,1550 doublet emission line was clearly detected with FWHM =120+/-20 km s-1 and a total rest-frame EW of 37-5+6 angstrom. We also report the detection of weak continuum emission, and the tentative detection of OIII] 1661,1666 in the 4 hour J band spectrum. Judging from the UV magnitude, line widths, luminosities, and EWs of Lyman alpha and CIV, we suggest that this source is a reionization-era analog of classical type-II AGNs, although there is a possibility that it represents a new population of AGN/galaxy composite objects in the early universe. We compare the properties of J1423-0018 to intermediate-redshift type-II AGNs and CIV emitters seen in z=6-7 galaxy samples. Further observations of other metal emission lines in the rest-frame UV or optical, and X-ray follow-up observations of the z=6-7 narrow-line quasars are needed for more robust diagnostics and to determine their nature.
description: 15 pages, 8 figures, accepted for publication in the Astrophysical Journal
Εισαγωγή στην Αλγεβρική Θεωρία Αριθμών και Εφαρμογές στις Διοφαντικές Εξισώσεις
Creators: name: Μπαλκατζοπούλου, Σοφία Αστέριου
Publisher: name: Aristotle University of Thessaloniki
Year: 2020
Subjects: Αλγεβρική Θεωρία Αριθμών
Διοφαντικές εξισώσεις
Fermat
Algebraic Number Theory
Diophantine Equations

description: Σκοπός αυτής της διπλωματικής είναι να κάνουμε μια εισαγωγή στην Αλγεβρική θεωρία αριθμών και να δείξουμε πως με τη βοήθεια της μπορούν να επιλυθούν προβλήματα των Διοφαντικών εξισώσεων, όπως το τελευταίο θεώρημα του Fermat. Aρχικά υπενθυμίζουμε κάποιους βασικούς ορισμούς και εργαλεία της Άλγεβρας που είναι απαραίτητα για το κυρίως θέμα. Έπειτα εισάγουμε τις έννοιες των αλγεβρικών αριθμών, αλγεβρικών ακεραίων καθώς και των ακεραίων του Gauss και του Eisenstein. Συνεχίζουμε με το θεμελειώδες θεώρημα του μονάδων του Dirichlet με καθοριστικό ρόλο στην Αλγεβρική θεωρία αριθμών. Αμέσως μετά αποδεικνύουμε οτι ένα στοιχείο του δακτυλίου των ακεραίων ενός σώματος μπορεί να παραγοντοποιηθεί σε ανάγωγους παράγοντες και ακόμη ορίζουμε στο δακτύλιο μοναδικής παραγοντοποίησης. Η ανάγκη για μοναδική παραγοντοποίηση ενός στοιχείου μας κάνει να παρουσιάσουμε στη συνέχεια τα ιδεώδη και τον αριθμό των κλάσεων τους. Τέλος παρουσιάζουμε πως εφαρμόζεται η Αλγεβρική θεωρία αριθμών στις Διοφαντικές εξισώσεις.
description: The aim of the present thesis is to make an introduction to Algebraic number theory and solve Diophantine equations based on her, just like the last theorem of Fermat. At first we remind basic definitions and tools of Algebra, which are important to the main subject. Afterwards we introduce the notions of algebraic numbers, algebraic integers as well as Gauss and Eisenstein integers. We continue with Dirichlet's fundamental unit theorem, which plays pivotal role in Algebraic number theory. Thereupon we proof that an element belongs to the ring of integers of a field can factor to irreducible factors and also we define unique factorization rings. Necessity for unique factorization of an element lead us to introduce ideals and the class number. At the end of this thesis we see how Algebraic number theory applys to Diophantine equations.
Σεισμική διακινδύνευση αστικών κέντρων: Ανάπτυξη μοντέλου στοιχείων υπό διακινδύνευση για το κτιριακό απόθεμα της πόλης της Κοζάνης -Εκτίμηση σεισμικής διακινδύνευσης με χρήση του λογισμικού OpenQuake engine
Creators: name: Παπαμαρινούδη, Μαρία Μαρίνου
Publisher: name: Aristotle University of Thessaloniki
Year: 2020
Subjects: Σεισμική Επικινδυνότητα
Σεισμική Διακινδύνευση
Στοιχεία υπό διακινδύνευση
Seismic Hazard
Seismic Risk
Exposure model

description: Περίληψη Η παρούσα διπλωματική εργασία πραγματεύεται το αντικείμενο της σεισμικής επικινδυνότητας και διακινδύνευσης αστικών κέντρων. Πιο συγκεκριμένα, μελετάται η σεισμική διακινδύνευση της πόλης της Κοζάνης. Στο πλαίσιο αυτό αναπτύχθηκε ένα μοντέλο υπό διακινδύνευση στοιχείων για το κτιριακό απόθεμα της Κοζάνης. Τα υπό διακινδύνευση στοιχεία αποτελούνται από κτίρια με χρήση κατοικίας και όλες οι απαραίτητες πληροφορίες και δεδομένα σχετικά με αυτά ελήφθησαν από την απογραφή του 2011 που πραγματοποιήθηκε από την Ελληνική Στατιστική Αρχή. Τα κτίρια αυτά ταξινομήθηκαν σε τυπολογίες σύμφωνα με το σύστημα ταξινόμησης που προτείνεται από την ερευνητική κοινότητα Global Earthquake Model (GEM). Όσον αφορά τη σεισμική τρωτότητα των κτιρίων, σε πρώτο στάδιο πραγματοποιήθηκαν αναλύσεις με τις καμπύλες τρωτότητας που προτείνονται από την διεθνή ερευνητική κοινότητα GEM και σε επόμενες αναλύσεις χρησιμοποιήθηκαν οι πιο πρόσφατες καμπύλες τρωτότητας που προτείνονται από την ερευνητική κοινότητα European Facilities for Earthquake Hazard and Risk (EFHER) στο πλαίσιο ανάπτυξης ενός πανευρωπαϊκού μοντέλου διακινδύνευσης (ESRM20).Αρχικά, μελετάται η σεισμική επικινδυνότητα και διακινδύνευση για το σενάριο του σεισμού της Κοζάνης – Γρεβενών 1995 και στη συνέχεια πραγματοποιείται μια πιθανολογική ανάλυση σεισμικής διακινδύνευσης για την περιοχή μελέτης. Τέλος, εξάγονται τα αποτελέσματα με την μορφή χαρτών και διαγραμμάτων, γίνεται η σύγκρισή τους με πραγματικές καταγραφές και εξάγονται τα αντίστοιχα συμπεράσματα.
description: This present diploma thesis examines the subject of seismic hazard and seismic risk of urban centers. More specifically the seismic risk of the city of Kozani is studied. Thus, an exposure model for the residential buildings of Kozani is developed. All the necessary information and data regarding the residential buildings derive from the 2011 population and housing census. The building taxonomy system of Global Earthquake Model (GEM) is used, in order to classify the buildings into categories. The seismic fragility and vulnerability of the buildings was simulated using the respective curves that the Global Earthquake Model community proposed. Afterwards, analyses were conducted using the fragility curves that the European Facilities for Earthquake Hazard and Risk (EFHER) proposed in the context of the European Seismic Risk Model (ESRM20) project. Seismic hazard and risk analyses are conducted for the earthquake of Kozani – Grevena 1995. An event stochastic probabilistic analysis is, also, conducted for the city of Kozani. Finally, the results are presented through maps and diagrams, they are compared with real recordings of the earthquake and the conclusions are demonstrated.
Problems on automorphism groups of nonpositively curved polyhedral complexes and their lattices
Creators: name: Farb, Benson
name: Hruska, G. Christopher
name: Thomas, Anne
Publisher: name: arXiv
Year: 2008
Subjects: subject: Group Theory (math.GR)
subject: FOS: Mathematics

description: The goal of this paper is to present a number of problems about automorphism groups of nonpositively curved polyhedral complexes and their lattices, meant to highlight possible directions for future research.
description: 39 pages, 2 figures. To appear in Festschrift in honor of Robert Zimmer's 60th Birthday. Version 2: incorporates many useful comments and some new problems suggested by Frederic Haglund
Growth optimization of TaN for superconducting spintronics
Creators: name: Müller, Manuel
name: Hoepfl, Raphael
name: Liensberger, Lukas
name: Geprägs, Stephan
name: Huebl, Hans
name: Weiler, Mathias
name: Gross, Rudolf
name: Althammer, Matthias
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We have optimized the growth of superconducting TaN thin films on \ch{SiO2} substrates via dc magnetron sputtering and extract a maximum superconducting transition temperature of $T_{\mathrm{c}}=5$ K as well as a maximum critical field $μ_0H_{\mathrm{c2}}=(13.8\pm0.1)$ T. To investigate the impact of spin-orbit interaction in superconductor/ferromagnet heterostructures, we then analyze the magnetization dynamics of both normal state and superconducting TaN/\ch{Ni80Fe20}(Permalloy, Py)-bilayers as a function of temperature using broadband ferromagnetic resonance (bbFMR) spectroscopy. The phase sensitive detection of the microwave transmission signal is used to quantitatively extract the inverse current-induced torques of the bilayers. The results are compared to our previous study on NbN/Py-bilayers. In the normal state of TaN, we detect a positive damping-like current-induced torque $σ_{\mathrm{d}}$ from the inverse spin Hall effect (iSHE) and a small field-like torque $σ_{\mathrm{f}}$ attributed to the inverse Rashba-Edelstein effect (iREE) at the TaN/Py-interface. In the superconducting state of TaN, we detect a negative $σ_{\mathrm{d}}$ attributed to the quasiparticle mediated inverse spin Hall effect (QMiSHE) and the unexpected manifestation of a large positive field-like $σ_{\mathrm{f}}$ of unknown origin matching our previous results for NbN/Py-bilayers.
description: 6 pages 4 figures
Controlling the accuracy of unconditionally stable algorithms in Cahn-Hilliard Equation
Creators: name: Cheng, Mowei
name: Warren, James A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Given an unconditionally stable algorithm for solving the Cahn-Hilliard equation, we present a general calculation for an analytic time step $\d τ$ in terms of an algorithmic time step $\dt$. By studying the accumulative multi-step error in Fourier space and controlling the error with arbitrary accuracy, we determine an improved driving scheme $\dt=At^{2/3}$ and confirm the numerical results observed in a previous study \cite{Cheng1}.
description: 4 pages, latex
Theory and simulation of shock waves: Entropyproduction and energy conversion
Creators: name: Hafskjold, Bjørn
name: Bedeaux, Dick
name: Wilhelmsen, Øivind
name: Kjelstrup, Signe
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We have considered a shock wave as a surface of discontinuity and computed the entropy production using non-equilibrium thermodynamics for surfaces. The results from this method, which we call the "Gibbs excess method" (GEM), were compared with results from three alternative methods, all based on the entropy balance in the shock front region, but with different assumptions about local equilibrium. Non-equilibrium molecular dynamics (NEMD) simulations were used to simulate a thermal blast in a one-component gas consisting of particles interacting with the Lennard-Jones/spline potential. This provided data for the theoretical analysis. Two cases were studied, a weak shock with Mach number $M \approx 2$ and a strong shock with $M \approx 6$ and with a Prandtl number of the gas $Pr \approx 1.4$ in both cases. The four theoretical methods gave consistent results for the time-dependent surface excess entropy production for both Mach numbers. The internal energy was found to deviate only slightly from equilibrium values in the shock front. The pressure profile was found to be consistent with the Navier-Stokes equations. The entropy production in the weak and strong shocks were approximately proportional to the square of the Mach number and decayed with time at approximately the same relative rate. In both cases, some 97 \% of the total entropy production in the gas occurred in the shock wave. The GEM showed that most of the shock's kinetic energy was converted reversibly into enthalpy and entropy, and a small amount was dissipated as produced entropy. The shock waves traveled at almost constant speed and we found that the overpressure determined from NEMD simulations agreed well with the Rankine-Hugoniot conditions for steady-state shocks.
description: 27 pages, 16 figures, Supporting material, Symbol lists
Little Higgs model effects at $γγ$ collider
Creators: name: Choudhury, S. Rai
name: Cornell, A. S.
name: Gaur, Naveen
name: Goyal, Ashok
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Though the predictions of the Standard Model (SM) are in excellent agreement with experiments there are still several theoretical problems, such as fine-tuning and the hierarchy problem. These problems are associated with the Higgs sector of the SM, where it is widely believed that some {\it ``new physics"} will take over at the TeV scale. One beyond the SM theory which resolves these problems is the Little Higgs (LH) model. In this work we shall investigate the effects of the LH model on $\gggg$ scattering; where the process $\gggg$ at high energies occurs in the SM through diagrams involving $W$, charged quark and lepton loops (and is, therefore, particularly sensitive to any new physics
description: RevTex 4.0 file, 12 pages including 15 eps figures, version accepted in PRD
Training Saturation in Layerwise Quantum Approximate Optimisation
Creators: name: Campos, E.
name: Rabinovich, D.
name: Akshay, V.
name: Biamonte, J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Quantum Approximate Optimisation (QAOA) is the most studied gate based variational quantum algorithm today. We train QAOA one layer at a time to maximize overlap with an $n$ qubit target state. Doing so we discovered that such training always saturates -- called \textit{training saturation} -- at some depth $p^*$, meaning that past a certain depth, overlap can not be improved by adding subsequent layers. We formulate necessary conditions for saturation. Numerically, we find layerwise QAOA reaches its maximum overlap at depth $p^*=n$. The addition of coherent dephasing errors to training removes saturation, recovering robustness to layerwise training. This study sheds new light on the performance limitations and prospects of QAOA.
description: 7 pages; RevTEX
Classicality in Quantum Mechanics
Creators: name: Dreyer, Olaf
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this article we propose a solution to the measurement problem in quantum mechanics. We point out that the measurement problem can be traced to an a priori notion of classicality in the formulation of quantum mechanics. If this notion of classicality is dropped and instead classicality is defined in purely quantum mechanical terms the measurement problem can be avoided. We give such a definition of classicality. It identifies classicality as a property of large quantum system. We show how the probabilistic nature of quantum mechanics is a result of this notion of classicality. We also comment on what the implications of this view are for the search of a quantum theory of gravity.
description: Converence talk presented at DICE 2006 in Piombino. To be published in the Journal of Physics: Conference Series
Linear Nearest Neighbor Flocks with All Distinct Agents
Creators: name: Lyons, R.
name: Veerman, J. J. P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: Applied Physics (physics.app-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 37N35, 93D99

description: This paper analyzes the global dynamics of 1-dimensional agent arrays with nearest neighbor linear couplings. The equations of motion are second order linear ODEs with constant coeffcients. The novel part of this research is that the couplings are different for each distinct agent. We allow the forces to depend on the positions and velocity (damping terms) but the magnitudes of both the position and velocity couplings are different for each agent. We, also, do not assume that the forces are "Newtonian" (i.e. the force due to A on B equals the minus the force of B on A) as this assumption does not apply to certain situations, such as traffic modeling. For example, driver A reacting to driver B does not imply the opposite reaction in driver B. There are no known analytical means to solve these systems, even though they are linear, and so relatively little is known about them. This paper is a generalization of previous work that computed the global dynamics of 1-dimensional sequences of identical agents [3] assuming periodic boundary conditions. In this paper, we push that method further, similar to [2], and use an extended periodic boundary condition to to gain quantitative insights to the systems under consideration. We find that we can approximate the global dynamics of such a system by carefully analyzing the low-frequency behavior of the system with (generalized) periodic boundary conditions.
description: 17 pages, 10 figures
Nearly-one-dimensional self-attractive Bose-Einstein condensates in optical lattices
Creators: name: Salasnich, L.
name: Cetoli, A.
name: Malomed, B. A.
name: Toigo, F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: Within the framework of the mean-field description, we investigate atomic Bose-Einstein condensates (BECs), with attraction between atoms, under the action of strong transverse confinement and periodic (optical-lattice, OL) axial potential. Using a combination of the variational approximation (VA), one-dimensional (1D) nonpolynomial Schrödinger equation (NPSE), and direct numerical solutions of the underlying 3D Gross-Pitaevskii equation (GPE), we show that the ground state of the condensate is a soliton belonging to the semi-infinite bandgap of the periodic potential. The soliton may be confined to a single cell of the lattice, or extend to several cells, depending on the effective self-attraction strength, $g$ (which is proportional to the number of atoms bound in the soliton), and depth of the potential, $V_{0}$, the increase of $V_{0}$ leading to strong compression of the soliton. We demonstrate that the OL is an effective tool to control the soliton's shape. It is found that, due to the 3D character of the underlying setting, the ground-state soliton collapses at a critical value of the strength, $g=g_{c}$, which gradually decreases with the increase of the depth of the periodic potential, $V_{0}$; under typical experimental conditions, the corresponding maximum number of $^{7}$Li atoms in the soliton, $N_{\max}$, ranges between $8,000$ and $4,000$. Examples of stable multi-peaked solitons are also found in the first finite bandgap of the lattice spectrum. The respective critical value $g_{c}$ again slowly decreases with the increase of $V_{0}$, corresponding to $N_{\max }\simeq 5,000$.
description: 9 pages, 8 figures, 2 tables
Deep Learning Approaches for Forecasting Strawberry Yields and Prices Using Satellite Images and Station-Based Soil Parameters
Creators: name: Chaudhary, Mohita
name: Gastli, Mohamed Sadok
name: Nassar, Lobna
name: Karray, Fakhri
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Computational tools for forecasting yields and prices for fresh produce have been based on traditional machine learning approaches or time series modelling. We propose here an alternate approach based on deep learning algorithms for forecasting strawberry yields and prices in Santa Barbara county, California. Building the proposed forecasting model comprises three stages: first, the station-based ensemble model (ATT-CNN-LSTM-SeriesNet_Ens) with its compound deep learning components, SeriesNet with Gated Recurrent Unit (GRU) and Convolutional Neural Network LSTM with Attention layer (Att-CNN-LSTM), are trained and tested using the station-based soil temperature and moisture data of SantaBarbara as input and the corresponding strawberry yields or prices as output. Secondly, the remote sensing ensemble model (SIM_CNN-LSTM_Ens), which is an ensemble model of Convolutional NeuralNetwork LSTM (CNN-LSTM) models, is trained and tested using satellite images of the same county as input mapped to the same yields and prices as output. These two ensembles forecast strawberry yields and prices with minimal forecasting errors and highest model correlation for five weeks ahead forecasts.Finally, the forecasts of these two models are ensembled to have a final forecasted value for yields and prices by introducing a voting ensemble. Based on an aggregated performance measure (AGM), it is found that this voting ensemble not only enhances the forecasting performance by 5% compared to its best performing component model but also outperforms the Deep Learning (DL) ensemble model found in literature by 33% for forecasting yields and 21% for forecasting prices
description: Paper Accepted in Association for the Advancement of Artificial Intelligence (AAAI) Spring Symposium on 21st Jan, 2021
Arming Teachers for School Safety: Providing Clarity for State Policies
Creators: name: Isbell, Laura
name: Dixon, Kathryn
name: Sanders, April
Publisher: name: Texas Education Review
Year: 2019
Subjects: school safety
school violence
school policy
gun violence

description: While there is an increased national focus on student safety and gun violence in schools, the policies for arming teachers are often vague and unclear. Additionally, policies and laws enforcing safety protocol for students differ across states. Clarity in policies are important for stakeholders in school communities who can use such information to better understand the shifting landscape of policy about arming faculty and staff. In this paper, we explored the creation of specific policies designed to arm school personnel in Texas, including the Marshal Plan and the School Firearm and Safety Action Plan, known as the Guardian Plan. Findings may be applied to districts and governments in other states as they construct laws and policies related to school safety.
Robust Model Predictive Path Integral Control: Analysis and Performance Guarantees
Creators: name: Gandhi, Manan
name: Vlahov, Bogdan
name: Gibson, Jason
name: Williams, Grady
name: Theodorou, Evangelos A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: Optimization and Control (math.OC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Mathematics

description: In this paper we propose a novel decision making architecture for Robust Model Predictive Path Integral control (RMPPI) and investigate its performance guarantees and applicability to off-road navigation. Key building blocks of the proposed architecture are an augmented state space representation of the system consisting of nominal and actual dynamics, a placeholder for different types of tracking controllers, a safety logic for nominal state propagation, and an importance sampling scheme that takes into account the capabilities of the underlying tracking control. Using these ingredients, we derive a bound on the free energy growth of the dynamical system which is a function of task constraint satisfaction level, the performance of the underlying tracking controller, and the sampling error of the stochastic optimization used within RMPPI. To validate the bound on free energy growth, we perform experiments in simulation using two types of tracking controllers, namely the iterative Linear Quadratic Gaussian and Contraction-Metric based control. We further demonstrate the applicability of RMPPI in real hardware using the GT AutoRally vehicle. Our experiments demonstrate that RMPPI outperforms MPPI and Tube-MPPI by alleviating issues of the aforementioned model predictive controllers related to either lack of robustness or excessive conservatism. RMPPI provides the best of the two worlds in terms of agility and robustness to disturbances.
description: To be published in Robotics and Automation Letters
Access to Dual Enrollment in the United States: Implications for Equity and Stratification
Creators: name: Rivera, Luis E.
name: Kotok, Stephen
name: Ashby, Nathan
Publisher: name: Texas Education Review
Year: 2019
Subjects: dual enrollment
dual credit
equity
human capital
opportunity gap

description: Dual enrollment (DE) programs are on the rise nationally. This study uses recently available nationally representative data to examine which student and school characteristics predict participation in DE in the United States. We connect DE participation to human capital theory and related educational policy values of equity, excellence, and efficiency. Using logistic regressions, we find that, on average, 9thgrade GPA and attendance as well as higher socioeconomic status increased the odds that a student participates in DE. Our analysis also detects geographic disparities with students in rural areas and the South being more likely to take DE. We discuss implications for educational and economic policy.
Random bipartite entanglement from W and W-like states
Creators: name: Fortescue, Ben
name: Lo, Hoi-Kwong
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We describe a protocol for distilling maximally entangled bipartite states between random pairs of parties from those sharing a tripartite W state, and show that, rather surprisingly, the total distillation rate (the total number of EPR pairs distilled per W, irrespective of who shares them) may be done at a higher rate than distillation of bipartite entanglement between specified pairs of parties. Specifically, the optimal distillation rate for specified entanglement for the W has been previously shown to be the asymptotic entanglement of assistance of 0.92 EPR pairs per W, while our protocol can asymptotically distill 1 EPR pair per W between random pairs of parties, which we conjecture to be optimal. We thus demonstrate a tradeoff between the overall asymptotic rate of EPR distillation and the distribution of final EPR pairs between parties. We further show that by increasing the number of parties in the protocol that there exist states with fixed lower-bounded distillable entanglement for random parties but arbitrarily small distillable entanglement for specified parties.
description: 5 pages, 1 figure, RevTeX. v2 - upper bound on random distillation is expressed more generally and corollaries to the bound added. Minor notation changes. v3 - further notation changes (Ernd now designated Et), discussion of finite distillation rounds and single-copy bound on Et added. Theorem added - relative entropy is shown to be an upper bound to Et for all pure states. Discussion of W formation from EPRs (previously shown in others' work) removed. Some addition, removal and reordering of references
Dynamical gravastars from the interaction between scalar fields and matter
Creators: name: de Oca, Alejandro Cabo Montes
name: Fontanella, Duvier Suarez
name: Valls-Gabaud, David
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Gravastars are configurations of compact singularity-free gravitational objects which are interesting alternatives to classical solutions in the strong gravitational field regime. Although there are no static star-like solutions of the Einstein-Klein-Gordon equations for real scalar fields, we show that dynamical gravastars solutions arise through the direct interaction of a scalar field with matter. Two configurations presented here show that, within the internal zone, the scalar field plays a role similar to a cosmological constant, while the scalar field decays at large distances as the Yukawa potential. Like classical gravastars, these solutions exhibit small values of the temporal metric component near a transitional radial value, although this behaviour is not determined by the de Sitter nature of the internal space-time, but rather by a slowly-varying scalar field. The scalar field-matter interaction is able to define trapping forces that rigorously confine the polytropic gases to the interior of a sphere. At the surface of these spheres, pressures generated by the field-matter interaction play the role of "walls" preventing the matter from flowing out. These solutions predict a stronger scattering of the accreting matter with respect to Schwarzschild black holes.
description: 12 pages, 8 figures
Single-file dynamics with different diffusion constants
Creators: name: Ambjornsson, Tobias
name: Lizana, Ludvig
name: Lomholt, Michael A.
name: Silbey, Robert J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We investigate the single-file dynamics of a tagged particle in a system consisting of N hardcore interacting particles (the particles cannot pass each other) which are diffusing in a one-dimensional system where the particles have different diffusion constants. For the two particle case an exact result for the conditional probability density function (PDF) is obtained for arbitrary initial particle positions and all times. The two-particle PDF is used to obtain the tagged particle PDF. For the general N-particle case (N large) we perform stochastic simulations using our new computationally efficient stochastic simulation technique based on the Gillespie algorithm. We find that the mean square displacement for a tagged particle scales as the square root of time (as for identical particles) for long times, with a prefactor which depends on the diffusion constants for the particles; these results are in excellent agreement with very recent analytic predictions in the mathematics literature.
description: 9 pages, 5 figures. Journal of Chemical Physics (in press)
Parametric representation of mixtures with two pure components
Creators: name: Kuntman, M. A.
name: Kuntman, E.
name: Kuntman, A.
Publisher: name: Zenodo
Year: 2019
Subjects: mixed states, mixtures, pure states, deterministic systems, optics, Mueller matrix, decomposition of mixtures, retrieval of preparation states, coherent combination, incoherent combination, eigenvalue decomposition, spectral decomposition, spinors, parametric decomposition, spinor basis, polarimetry, ellipsometry, two-component mixtures, depolarization, depolarizing Mueller matrix
unitary transformations, density matrix, rank of a matrix, vector spaces, orthogonal basis, orthonormal basis, nonorthogonal basis, subspaces,, standard basis

description: Abstract: At the state preparation stage, pure states can be combined coherently or incoherently. Pure states can be represented by vector states and coherent combinations of pure states result in pure states. Incoherent combinations of pure states are mixed states and they can be represented by density matrices. Pure component states, in general, may not be orthogonal to each other and
 there are infinitely many sets of pure states that can be combined to yield the same mixed state. Mixtures (mixed states) with only two pure components are relatively easy to study. This work focuses on two-component mixtures to show that they can be parametrized by only two real parameters. The parameters define the orientations of pure component states in a two dimensional complex subspace and their associated weights.
 This means that all possible decompositions of two-component mixtures can be generated by two vectors and two associated weights that can be expressed in a parametric form with two real parameters. The proposed parametric decomposition procedure is quite general and it can be applied to quantum mechanical two-component mixtures and to depolarizing Mueller matrices that result as an incoherent combination of two deterministic optical systems.
Chain motion and viscoelasticity in highly entangled solutions of semiflexible rods
Creators: name: Ramanathan, Shriram
name: Morse, David C
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Brownian dynamics simulations are used to study highly entangled solutions of semiflexible polymers. Bending fluctuations of semiflexible rods are signficantly affected by entanglement only above a concentration $c^{**}$, where $c^{**}\sim 10^{3}L^{-3}$ for chains of similar length $L$ and persistence length. For $c > c^{**}$, the tube radius $R_{e}$ approaches a dependence $R_{e} \propto c^{-3/5}$, and the linear viscoelastic response develops an elastic contribution that is absent for $c < c^{**}$. Experiments on isotropic solutions of $F$-actin span concentrations near $c^{**}$ for which the predicted asymptotic scaling of the plateau modulus $G \propto c^{7/5}$ is not yet valid.
description: 4 pages, 5 figures, submitted to PRL
The role of $D^{\star\star}$ in $B^-\to D_s^+ K^- π^-$
Creators: name: Antipin, Oleg
name: Valencia, G.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The BaBar collaboration has recently reported the observation of the decay mode $B^-\to D_s^+ K^- π^-$. We investigate the role played by the $D^{\star\star}$ resonances in this decay mode using HQET. Although these resonances cannot appear as physical intermediate states in this reaction, their mass is very close to the $D_s^+ K^-$ production threshold and may, therefore, play a prominent role. We pursue this possibility to extract information on the properties of the strong $D^{\star\star} D M$ couplings. As a byproduct of this analysis we point out that future super-$B$ factories may be able to measure the $D_0^0 D^\star γ$ radiative coupling through the reaction $B^-\to D^\star γπ^-$.
description: Version to appear in Physics Letters B
The Galactic HII Region Luminosity Function at Radio and Infrared Wavelengths
Creators: name: Mascoop, J. L.
name: Anderson, L. D.
name: Wenger, Trey. V.
name: Makai, Z.
name: Armentrout, W. P.
name: Balser, Dana. S.
name: Bania, T. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Galactic HII region luminosity function (LF) is an important metric for understanding global star formation properties of the Milky Way, but only a few studies have been done and all use relatively small numbers of HII regions. We use a sample of 797 first Galactic quadrant HII regions compiled from the WISE Catalog of Galactic HII Regions to examine the form of the LF at multiple infrared and radio wavelengths. Our sample is statistically complete for all regions powered by single stars of type O9.5V and earlier. We fit the LF at each wavelength with single and double power laws. Averaging the results from all wavelengths, the mean of the best-fit single power law index is $\langleα\rangle=-1.75\,\pm\,0.01$. The mean best-fit double power law indices are $\langleα_1\rangle=-1.40\,\pm\,0.03$ and $\langleα_2\rangle=-2.33\,\pm\,0.04$. We conclude that neither a single nor a double power law is strongly favored over the other. The LFs show some variation when we separate the HII region sample into subsets by heliocentric distance, physical size, Galactocentric radius, and location relative to the spiral arms, but blending individual HII regions into larger complexes does not change the value of the power law indices of the best-fit LF models. The consistency of the power law indices across multiple wavelengths suggests that the LF is independent of wavelength. This implies that infrared and radio tracers can be employed in place of H$α$.
description: 41 pages, 21 figures, 6 tables. Accepted for publication in ApJ
Children’s ego functioning and their stage of moral reasoning
Creators: name: Matsuba, Michio K.
Publisher: name: University of British Columbia
Year: 2008

description: It has been claimed that both peer and family interactions are important in facilitating moral development. As well, there has been evidence suggesting that children's ego functioning is an important consideration in understanding moral functioning. This study investigated the relationship among these variables and how they relate to children’s moral reasoning level. Forty target children (Grade 5 and 10) participated along with a same-sex friend and a parent (total N = 120). Each participant's stage of moral development was assessed in a moral judgment interview. Target children also participated in two discussion sessions (one with a friend and one with a parent). In each discussion, three moral conflicts were discussed (two real-life and one hypothetical). Target children's ego functioning in these discussion sessions was rated by observers using a Q-sort procedure. Results revealed that older children tended to use more complex ego processes than younger children. As well, children generally “coped" more in discussing hypothetical dilemmas and "defended" more with real-life dilemmas. The predicted differences in ego functioning when discussing dilemmas with a peer versus a parent were not evident. However, consistent with expectations, a strong relation was found between ego functioning and level of moral reasoning with moral development being predicted by both cognitive coping and attention-focusing coping ego functions. The results are discussed in terms of the factors that foster moral growth in children.
Optical frequency standard with $Sr^+$: A theoretical many-body approach
Creators: name: Sur, Chiranjib
name: Latha, K. V. P.
name: Chaudhuri, Rajat K.
name: Das, B. P.
name: Mukherjee, D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Demands from several areas of science and technology have lead to a worldwide search for accurate optical clocks with an uncertainty of 1 part in $10^{18}$, which is $10^{3}$ times more accurate than the present day cesium atomic clocks based on microwave frequency regime. In this article we discuss the electric quadrupole and the hyperfine shifts in the $5s ^{2}S_{1/2}\longrightarrow4d ^{2}D_{5/2}$ clock transition in $\mathrm{Sr^{+}}$, one of the most promising candidates for next generation optical clocks. We have applied relativistic coupled cluster theory for determining the electric quadrupole moment of the $4d ^{2}D_{5/2}$ state of $\mathrm{^{88}Sr^{+}}$ and the magnetic dipole ($A$) and electric quadrupole ($B$) hyperfine constants for the $5s ^{2}S_{1/2}$ and $4d ^{2}D_{5/2}$ states which are important in the study of frequency standards with $\mathrm{Sr^{+}}$. The effects of electron correlation which are very crucial for the accurate determination of these quantities have been discussed.
description: TC-2005 Conference, India, 2 EPS figures, Latex 2e
Resonance refraction and neutrino oscillations
Creators: name: Smirnov, Alexei Y.
name: Valera, Victor B.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The refraction index and matter potential depend on neutrino energy and this dependence has a resonance character associated to the production of the mediator in the $s-$channel. For light mediators and light particles of medium (background) the resonance can be realized at energies accessible to laboratory experiments. We study properties of the energy dependence of the potential for different C-asymmetries of background. Interplay of the background potential and the vacuum term leads to (i) bump in the oscillation probability in the resonance region, (ii) dip related to the MSW resonance in the background, (iii) substantial deviation of the effective $Δm^2$ above the resonance from the low energy value, etc. We considered generation of mixing in the background. Interactions with background shifts the energy of usual MSW resonance and produces new MSW resonances. Searches of the background effects allow us to put bounds on new interactions of neutrinos and properties of the background. We show that explanation of the MiniBooNE excess, as the bump due to resonance refraction, is excluded.
description: 36 pages, 6 figures
Signatures of synchrotron emission and of electron acceleration in the X-ray spectra of Mrk 421
Creators: name: Tramacere, A.
name: Massaro, F.
name: Cavaliere, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: BL Lac objects undergo strong flux variations involving considerable changes in their spectral shapes. We specifically investigate the X-ray spectral evolution of Mrk 421 over a time span of about nine years. We aim at statistically describing and physically understanding the large spectral changes in X rays observed in Mrk 421 over this time span. We perform a homogeneous spectral analysis of a wide data set including archived observations with ASCA, BeppoSax, RXTE, as well as published and unpublished XMM-Newton data. The presence of uncertainties is taken into account in our correlation analysis. The significance of the correlations found and possible spurious effects are studied with Monte Carlo simulations. We find that the Mrk421 spectral energy distribution (SED) has a lower peak at energies that vary in the range, 0.1-10 keV while its X-ray spectrum is definitely curved. Parameterizing the X-ray spectra with a log-parabolic model, we find a positive correlation between the position and the height of the SED peak. In addition, we find a negative trend of the spectral curvature parameter vs. the SED peak energy. We show that these relations between the spectral parameters are consistent with statistical or stochastic acceleration of the emitting particles, and provide insight into the physical processes occurring in BL Lac nuclei.
description: 11 pages, 5 fiures, Accepted for publication in A&A
Fluid-bicontinuous emulsions stabilized by colloidal particles
Creators: name: Clegg, P. S.
name: Herzig, E. M.
name: Schofield, A. B.
name: Egelhaaf, S. U.
name: Horozov, T. S.
name: Binks, B. P.
name: Cates, M. E.
name: Poon, W. C. K.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Using controlled spinodal decomposition, we have created a fluid-bicontinuous structure stabilized by colloidal particles. We present confocal microscopy studies of these structures and their variation with kinetic pathway. Our studies reveal a rigid multilayer of colloidal particles jammed at the interface which prevents the liquids demixing for many hours. The arrangement of two-fluid domains, interpenetrating on the meso-scale, could be useful as a microreaction medium.
description: 12 pages, 4 figures
Entanglement dynamics in chains of qubits with noise and disorder
Creators: name: Tsomokos, D. I.
name: Hartmann, M. J.
name: Huelga, S. F.
name: Plenio, M. B.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: The entanglement dynamics of arrays of qubits is analysed in the presence of some general sources of noise and disorder. In particular, we consider linear chains of Josephson qubits in experimentally realistic conditions. Electromagnetic and other (spin or boson) fluctuations due to the background circuitry and surrounding substrate, finite temperature in the external environment, and disorder in the initial preparation and the control parameters are embedded into our model. We show that the amount of disorder that is typically present in current experiments does not affect the entanglement dynamics significantly, while the presence of noise can have a drastic influence on the generation and propagation of entanglement. We examine under which circumstances the system exhibits steady-state entanglement for both short (N < 10) and long (N > 30) chains and show that, remarkably, there are parameter regimes where the steady-state entanglement is strictly non-monotonic as a function of the noise strength. We also present optimized schemes for entanglement verification and quantification based on simple correlation measurements that are experimentally more economic than state tomography.
description: 17 pages, 9 figures (replaced with published version: updated references, minor changes and typos)
Excitation Amplitude Dependence of Low Frequency Magneto-impedance of Amorphous Fe73.5Nb3Cu1Si13.5B9 Ribbon
Creators: name: Kaviraj, B.
name: Ghatak, S. K.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Magneto-impedance (MI) of soft ferromagnetic materials is a sensitive function of the amplitude and frequency of exciting a.c magnetic field. MI (Z) of amorphous ferromagnetic ribbon of nominal composition Fe73.5Nb3 Cu1 Si13.5 B9 is measured at different excitation currents with frequency ranging from 30kHz to 120KHz The excitation (a.c) and biasing (d.c) magnetic fields Hdc are parallel to ribbon axis. At zero dc fields, Z exhibits non-linear dependence on excitation amplitude whereas at higher d.c fields (9Oe) Z is nearly independent of excitation amplitude. The impedance is maximum at zero bias field and sharply decreases as Hdc increases and almost zero hysterisis has been observed as Hdc is scanned. The maximum relative change of impedance (Z(H)-Z(H=0))/Z(H=0) is found to increase from nearly 45 to 60 percent when the excitation fields goes up from 14A/m to 140A/m. The large MI is associated with screening of electromagnetic field by magnetization induced by exciting ac field.
description: 8 pages, 3 figures