cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Force-extension curves of bacterial flagella
Creators: name: Vogel, Reinhard
name: Stark, Holger
Publisher: name: arXiv
Year: 2010
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Cell Behavior (q-bio.CB)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Bacterial flagella assume different helical shapes during the tumbling phase of a bacterium but also in response to varying environmental conditions. Force-extension measurements by Darnton and Berg explicitly demonstrate a transformation from the coiled to the normal helical state [N.C. Darnton and H.C. Berg, Biophys. J. {92}, 2230 (2007)]. We here develop an elastic model for the flagellum based on Kirchhoff's theory of an elastic rod that describes such a polymorphic transformation and use resistive force theory to couple the flagellum to the aqueous environment. We present Brownian dynamics simulations that quantitatively reproduce the force-extension curves and study how the ratio $Γ$ of torsional to bending rigidity and the extensional rate influence the response of the flagellum. An upper bound for $Γ$ is given. Using clamped flagella, we show in an adiabatic approximation that the mean extension, where a local coiled-to-normal transition occurs first, depends on the logarithm of the extensional rate.
description: 13 pages, 23 figures; The final publication is vailable at http://www.epj.org; Supplementary material in the form of two movies available from the Journal web page
Step velocity tuning of SrRuO3 step flow growth on SrTiO3
Creators: name: Estève, D.
name: Maroutian, T.
name: Pillard, V.
name: Lecoeur, Ph.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Taking advantage of vicinal (001) SrTiO3 substrates with different mean terrace widths, the heteroepitaxial growth of SrRuO3 in the step flow mode has been mapped as a function of mean step velocity. Transition between stable and unstable step flow is shown to occur at a well-defined critical step velocity, with a step bunching instability observed below this threshold. The ability to pass from unstable to stable step flow during growth upon increasing the mean step velocity is demonstrated. This result is discussed in terms of a stress-based driving force for step bunching in competition with an effective step-up adatom current.
description: 4 pages, 3 figures
Valence band and core-level analysis of highly luminescent ZnO nanocrystals for designing ultrafast optical sensors
Creators: name: Joshi, Amish G.
name: Sahai, Sonal
name: Gandhi, Namita
name: Krishna, Y. G. Radha
name: Haranath, D.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Highly luminescent ZnO:Na nanocrystals of size ~2 nm were synthesized using a improved sol-lyophilization process. The surface analysis such as survey scan, core-level and valence band spectra of ZnO:Na nanocrystals were studied using x-ray photoelectron spectroscopy (XPS) to establish the presence of Na+ ions. The observed increase in band gap from 3.30 (bulk) to 4.16 eV (nano), is attributed to the quantum confinement of the motion of electron and holes in all three directions. The photoluminescence and decay measurements have complemented and supported our study to design an efficient and ultrafast responsive optical sensing device.
description: 10 Pages, 5 Figures
A lower bound for topological entropy of generic non Anosov symplectic diffeomorphisms
Creators: name: Catalan, Thiago
name: Tahzibi, Ali
Publisher: name: arXiv
Year: 2010
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We prove that a $C^1-$generic symplectic diffeomorphism is either Anosov or the topological entropy is bounded from below by the supremum over the smallest positive Lyapunov exponent of the periodic points. We also prove that $C^1-$generic symplectic diffeomorphisms outside the Anosov ones do not admit symbolic extension and finally we give examples of volume preserving diffeomorphisms which are not point of upper semicontinuity of entropy function in $C^1-$topology.
Reformulating polarized radiative transfer for astrophysical applications (I). A formalism allowing non-local Magnus solutions
Creators: name: Carlin, E. S.
name: Blanes, S.
name: Casas, F.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Mathematical Physics (math-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: The solar atmosphere is diagnosed by solving the polarized radiative transfer problem for plasmas in Non-Local Thermodynamic Equilibrium (NLTE). A key challenge in multidimensional NLTE diagnosis is to integrate efficiently the radiative transfer equation (RTE), but current methods are local, i.e. limited to constant propagation matrices. This paper introduces a formalism for non-local integration of the RTE using the Magnus expansion. We begin by framing the problem in terms of rotations within the Lorentz / Poincare group (Stokes formalism), motivating the use of the Magnus expansion. By combining the latter with a highly detailed algebraic characterization of the propagation matrix, we derive a compact analytical evolution operator that supports arbitrary variations of the propagation matrix and allows to increasingly consider any order in the Magnus expansion. Additionally, we also reformulate the inhomogeneous part of the RTE, again using the Magnus expansion, and introducing the new concept of inhomogeneous evolution operator. This provides the first consistent, general, and non-local formal solution to the RTE that is furthermore efficient and separates integration from the algebraic formal solution. Our framework is verified analytically and computationally, leading to a new family of numerical radiative transfer methods and potential applications such as accelerating NLTE calculations. With minor adjustments, our results apply to other universal physical problems sharing the Lorentz / Poincare algebra in special relativity and electromagnetism.
description: Published in The Open Journal of Astrophysics. 15+3 pages (including Appendix), 6 figures. Final version including all analytical details and numerical demonstration
Society and the social encyclicals--America's road out. By R.A. McGowan.
Creators: name: 1892-, McGowan, R. A. (Raymond Augustin),
Publisher: name: University of Notre Dame
Year: 2023

description:
 Three addresses delivered in the Catholic Hour ... on Sundays from May 9 to 23, 1937.
 Catholic hour (Radio program)
Conductive Atomic Force Microscopy of Chemically Synthesized Graphene Oxide and Interlayer Conduction
Creators: name: Kanamori, Yoshio
name: Obata, Seiji
name: Saiki, Koichiro
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Graphene oxide (GO) is one of chemically modified graphenes and has been extensively investigated worldwide. A monolayer sheet of GO can be chemically produced in solution and it has been expected to be adaptable to a wide variety of applications. Most of works have focused on fabrication and reduction processes of GO, while its intrinsic property has not been explored in detail. We have succeeded in fabricating large scale GO nanosheets reproducibly. In the present work, we observed GO nanosheets by conductive atomic force microscopy. The current image is useful to monitor the GO thickness as well as wrinkles and folds in the nanosheet with high contrast. In addition to the current images, local I-V characteristics of the GO sheet were measured with the conductive cantilever. Based on the applied electric filed dependence, the conduction normal to the GO sheet could be described in terms of Poole Frenkel emission mechanism and the relative permittivity of GO is evaluated to be 4.8.
description: 4 pages
Mechanics, dynamics and stability of turn-milling operations
Creators: name: Comak, Alptunc
Publisher: name: University of British Columbia
Year: 2018

description: Recent turn-milling machine tools are capable of carrying out turning, drilling, boring, milling and grinding operations simultaneously, hence they are widely used in industry to produce complex parts in a single set-up. Turn-milling machines have translational axes with a high speed spindle to hold the cutting tool and a low speed spindle to carry the workpiece. The resulting five-axis turn-milling machines can machine parts with complex curved tool paths. This thesis presents the mechanics and dynamics of turn-milling operations to predict cutting forces, torque, power, vibrations, chatter stability and dimensional surface errors in the virtual environment. First, the kinematics of five-axis turn milling operation is modeled using homogenous transformations. The engagement of rotating-moving tool with the rotating workpiece is identified using a commercial graphics system, and used in predicting the chip thickness distribution. The relative vibrations between the tool and workpiece are modeled, and superposed on the chip thickness in the engagement zone. Unlike in regular turning and milling operations with a single spindle which leads to a single and constant delay, turn milling has two time delays contributed by two rotating spindles and three translational feed drives. The regenerative chip thickness with dual delay is used to predict the cutting forces at tool-workpiece engagement zone, which are transformed to three Cartesian directions of the machine. The resulting coupled differential equations with two delays and time periodic coefficients are solved in the semi-discrete time domain to predict chatter stability, cutting forces, vibrations, torque, power and dimensional surface errors simultaneously. The thesis presents the first comprehensive digital model of turn milling operations in the literature, and can be used to predict the most productive cutting conditions ahead of costly physical trials currently practiced in the industry.
BOLALAR KITOBXONLIGINING AHAMIYATI
Creators: name: Nosirova, Zakhrokhon
Publisher: name: Zenodo
Year: 2025

description: This article highlights the importance of children's reading. The author emphasizes the role of reading in the formation of children's psyche, thinking and worldview. Children's reading is not only a source of knowledge, but also develops their creative thinking, helps to master emotional and moral values. The article considers the need for children's books to be of high quality and enlightening, as well as the need to develop a reading culture in children as an important issue. The social and educational role of reading, the role of the family and society in promoting a reading culture are also discussed.
Exploring Saliency Bias in Manipulation Detection
Creators: name: Krinsky, Joshua
name: Bettis, Alan
name: Tang, Qiuyu
name: Moreira, Daniel
name: Bharati, Aparna
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The social media-fuelled explosion of fake news and misinformation supported by tampered images has led to growth in the development of models and datasets for image manipulation detection. However, existing detection methods mostly treat media objects in isolation, without considering the impact of specific manipulations on viewer perception. Forensic datasets are usually analyzed based on the manipulation operations and corresponding pixel-based masks, but not on the semantics of the manipulation, i.e., type of scene, objects, and viewers' attention to scene content. The semantics of the manipulation play an important role in spreading misinformation through manipulated images. In an attempt to encourage further development of semantic-aware forensic approaches to understand visual misinformation, we propose a framework to analyze the trends of visual and semantic saliency in popular image manipulation datasets and their impact on detection.
description: Published in: 2024 IEEE International Conference on Image Processing (ICIP)
KHz QPOs in LMXBs, relations between different frequencies and compactness of stars
Creators: name: Gangopadhyay, Taparati
name: Li, Xiang-Dong
name: Ray, Subharthi
name: Dey, Mira
name: Dey, Jishnu
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We suggest that the mass of four compact stars SAX J1808.4$-$3658, KS 1731$-$260, SAX J1750.8$-$2900 and IGR J17191$-$2821 can be determined from the difference in the observed kiloHertz quasi periodic oscillations (kHz QPO-s) of these stars. The stellar radius is very close to the marginally stable orbit $R_{ms}$ as predicted by Einstein's general relativity. It may be noted that the first of these stars was suggested to be a strange star more than a decade back by Li \emph{et al.} (1999) from the unique millisecond X-ray pulsations with an accurate determination of its rotation period. It showed kHz QPO-s eight years back and so far it is the only set that has been observed. This is the first time we give an estimate of the mass of the star and of three other compact stars in Low-Mass X-ray Binaries using their observed kHz QPO-s.
description: Accepted for publication in New Astronomy
Prescriptive Process Monitoring Under Resource Constraints: A Causal Inference Approach
Creators: name: Shoush, Mahmoud
Publisher: name: Zenodo
Year: 2021
Subjects: Prescriptive Process Monitoring

description: In this document, we provide supplementary material for the paper entitled "Prescriptive Process Monitoring Under Resource Constraints: A Causal Inference Approach." We give more results about the empirical threshold to compute an optimal threshold based on historical data and different treatment duration distributions.
Issues and answers: [speeches] Sponsored by Home Mission Board, Dept. of Interfaith Witness and Bishops' Committee for Ecumenical and Interreligious Affairs for National Conference of Catholic Bishops.. prepared by the Dept. of Interfaith Witness, Home Mission Board of the Southern Baptist Convention.
Creators: name: Not Assigned
Publisher: name: University of Notre Dame
Year: 2023

description:
 Cover title.
The magnetic structure of the $zigzag$ chain family Na$_{x}$Ca$_{1-x}$V$_2$O$_4$ determined by muon-spin rotation
Creators: name: Ofer, Oren
name: Ikedo, Yutaka
name: Goko, Tatsuo
name: Mansson, Martin
name: Sugiyama, Jun
name: Ansaldo, Eduardo J.
name: Brewer, Jess H.
name: Chow, Kim H.
name: Sakurai, Hiroya
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present muon-spin rotation measurements on polycrystalline samples of the complete family of the antiferromagnetic (AF) $zigzag$ chain compounds, Na$_x$Ca$_{1-x}$V$_2$O$_4$. In this family, we explore the magnetic properties from the metallic NaV$_2$O$_4$ to the insulating CaV$_2$O$_4$. We find a critical $x_c(\sim0.833)$ which separates the low and high Na-concentration dependent transition temperature and its magnetic ground state. In the $xx_c$ compounds, multiple sub-phases appear with temperature and $x$. Based on the muon data obtained in zero external magnetic field, a careful dipolar field simulation was able to reproduce the muon behavior and indicates a modulated helical incommensurate spin structure of the metallic AF phase. The incommensurate modulation period obtained by the simulation agrees with that determined by neutron diffraction.
description: 7 pages, 7 figures, accepted for publication in PRB
Topological insulators and superconductors
Creators: name: Qi, Xiao-Liang
name: Zhang, Shou-Cheng
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Topological insulators are new states of quantum matter which can not be adiabatically connected to conventional insulators and semiconductors. They are characterized by a full insulating gap in the bulk and gapless edge or surface states which are protected by time-reversal symmetry. These topological materials have been theoretically predicted and experimentally observed in a variety of systems, including HgTe quantum wells, BiSb alloys, and Bi$_2$Te$_3$ and Bi$_2$Se$_3$ crystals. We review theoretical models, materials properties and experimental results on two-dimensional and three-dimensional topological insulators, and discuss both the topological band theory and the topological field theory. Topological superconductors have a full pairing gap in the bulk and gapless surface states consisting of Majorana fermions. We review the theory of topological superconductors in close analogy to the theory of topological insulators.
description: 55 pages, 44 figures, Review article commissioned by the Review of Modern Physics. Please help us to improve the article by emailing us your comments and missing references
A Quantum Approach to Synthetic Minority Oversampling Technique (SMOTE)
Creators: name: Mohanty, Nishikanta
name: Behera, Bikash K.
name: Ferrie, Christopher
name: Dash, Pravat
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: The paper proposes the Quantum-SMOTE method, a novel solution that uses quantum computing techniques to solve the prevalent problem of class imbalance in machine learning datasets. Quantum-SMOTE, inspired by the Synthetic Minority Oversampling Technique (SMOTE), generates synthetic data points using quantum processes such as swap tests and quantum rotation. The process varies from the conventional SMOTE algorithm's usage of K-Nearest Neighbors (KNN) and Euclidean distances, enabling synthetic instances to be generated from minority class data points without relying on neighbor proximity. The algorithm asserts greater control over the synthetic data generation process by introducing hyperparameters such as rotation angle, minority percentage, and splitting factor, which allow for customization to specific dataset requirements. Due to the use of a compact swap test, the algorithm can accommodate a large number of features. Furthermore, the approach is tested on a public dataset of Telecom Churn and evaluated alongside two prominent classification algorithms, Random Forest and Logistic Regression, to determine its impact along with varying proportions of synthetic data.
description: 42 Pages, 23 Figures, 2 Tables
Nonlinear optical responses in superconductors under magnetic fields: quantum geometry and topological superconductivity
Creators: name: Tanaka, Hiroto
name: Watanabe, Hikaru
name: Yanase, Youichi
Publisher: name: arXiv
Year: 2024
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Noncentrosymmetric superconductors offer fascinating phenomena of quantum transport and optics such as nonreciprocal and nonlinear responses. Time-reversal symmetry breaking often plays an essential role in the emergence and enhancement of nonreciprocal transport. In this paper, we show the nonreciprocal optical responses in noncentrosymmetric superconductors arising from time-reversal symmetry breaking by demonstrating them in $s$-wave superconductors with a Rashba spin-orbit coupling and a magnetic field. Numerical results reveal the superconductivity-induced bulk photocurrent and second harmonic generation, which are forbidden at the zero magnetic field. We discuss the properties and mechanisms of the superconducting nonlinear responses emerging under the magnetic field. In particular, we investigate the magnetic-field dependence of the photocurrent conductivity and clarify the essential ingredients which give a contribution unique to superconductors under the magnetic field. This contribution is dominant in the low carrier density regime although the corresponding joint density of states is tiny. We attribute the enhancement to the quantum geometry. Moreover, the nonlinear conductivity shows peculiar sign reversal at the transition to the topological superconducting state. We propose a bulk probe of topological transition and quantum geometry in superconductors.
description: 36 pages, 21 figures
Formation of naked singularities in five-dimensional space-time
Creators: name: Yamada, Yuta
name: Shinkai, Hisa-aki
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We numerically investigate the gravitational collapse of collisionless particles in spheroidal configurations both in four and five-dimensional (5D) space-time. We repeat the simulation performed by Shapiro and Teukolsky (1991) that announced an appearance of a naked singularity, and also find that the similar results in 5D version. That is, in a collapse of a highly prolate spindle, the Kretschmann invariant blows up outside the matter and no apparent horizon forms. We also find that the collapses in 5D proceed rapidly than in 4D, and the critical prolateness for appearance of apparent horizon in 5D is loosened compared to 4D cases. We also show how collapses differ with spatial symmetries comparing 5D evolutions in single-axisymmetry, SO(3), and those in double-axisymmetry, U(1)$\times$U(1).
description: 5 pages, 5 figures, To be published in Phys. Rev. D
32114: Ghosts of students past
Creators: name: Project, Lockdown2020 and Beyond
Publisher: name: University of Oxford
Year: 2023
Subjects: classificationCode: 479999
subject: Other language, communication and culture not elsewhere classified

description: As noted by many contributions one of the benefits of lockdown was exploring local paths, hitherto neglected or not visited for some time. In a circular route from New Hinksey, over the railway bridge, then cut north you come across the new college sports grounds for Pembroke College and the older grounds. The latter have now been turned into a community project with the pavilion occasionally used as a pop-up cafe, the old cricket pitch as a communal picnic space, and the tennis courts turned into spaces to grow fruit and vegetables.
Simultaneous formation of Solar System giant planets
Creators: name: Guilera, O. M.
name: Fortier, A.
name: Brunini, A.
name: Benvenuto, O. G.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: In the last few years, the so-called "Nice model" has got a significant importance in the study of the formation and evolution of the solar system. According to this model, the initial orbital configuration of the giant planets was much more compact than the one we observe today. We study the formation of the giant planets in connection with some parameters that describe the protoplanetary disk. The aim of this study is to establish the conditions that favor their simultaneous formation in line with the initial configuration proposed by the Nice model. We focus in the conditions that lead to the simultaneous formation of two massive cores, corresponding to Jupiter and Saturn, able to achieve the cross-over mass (where the mass of the envelope of the giant planet equals the mass of the core, and gaseous runway starts) while Uranus and Neptune have to be able to grow to their current masses. We compute the in situ planetary formation, employing the numerical code introduced in our previous work, for different density profiles of the protoplanetary disk. Planetesimal migration is taken into account and planetesimals are considered to follow a size distribution between $r_p^{min}$ (free parameter) and $r_p^{max}= 100$ km. The core's growth is computed according to the oligarchic growth regime. The simultaneous formation of the giant planets was successfully completed for several initial conditions of the disk. We find that for protoplanetary disks characterized by a power law ($Σ\propto r^{-p}$), smooth surface density profiles ($p \leq 1.5$) favor the simultaneous formation. However, for steep slopes ($p\sim 2$, as previously proposed by other authors) the simultaneous formation of the solar system giant planets is unlikely ...
description: Accepted for publication in Astronomy and Astrophysics
Formation History of Metal-Poor Halo Stars with Hierarchical Model and the Effect of ISM accretion on the Most Metal-Poor Stars
Creators: name: Komiya, Yutaka
name: Habe, Asao
name: Suda, Takuma
name: Fujimoto, Masayuki Y.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We investigate the star formation and chemical evolution in the early universe by considering the merging history of the Galaxy in the ΛCDM scenario according to the extended Press-Schechter theory. We give some possible constraints from comparisons with observation of extremely metal-poor (EMP) stars. We demonstrate that (1) The hierarchical structure formation can explain the characteristics of the observed metallicity distribution function (MDF) including a break around [Fe/H]~-4. (2) A high mass IMF of peak mass ~10Msun with the contribution of binaries, derived from the statistics of carbon enhanced EMP stars (Komiya et al. 2007), predicts the frequency of low-mass survivors consistent with the number of EMP stars observed for -4~
description: 20 pages, 14 figures. ApJ accepted
Work of Love: A Theological Reconstruction of the Communion of Saints
Creators: name: DeLorenzo, Leonard J.
Publisher: name: University of Notre Dame
Year: 2023

description: The saints are good company. They are the heroes of the faith who blazed new and creative paths to holiness; they are the witnesses whose testimonies echo throughout the ages in the memory of the Church. Most Christians, and particularly Catholics, are likely to have their own favorite saints, those who inspire and 'speak' to believers as they pray and struggle through the challenges of their own lives. Leonard DeLorenzo's book addresses the idea of the communion of saints, rather than individual saints, with the conviction that what makes the saints holy and what forms them into a communion is one and the same. _Work of Love_ investigates the issue of communication within the _communio sanctorum_ and the fullness of Christian hope in the face of the meaning-or meaninglessness-of death. In an effort to revitalize a theological topic that for much of Catholic history has been an indelible part of the Catholic imaginary, DeLorenzo invokes the ideas of not only many theological figures (Rahner, Ratzinger, Balthasar, and de Lubac, among others) but also historians, philosophers (notably Heidegger and Nietzsche), and literary figures (Rilke and Dante) to create a rich tableau. By working across several disciplines, DeLorenzo argues for a vigorous renewal in the Christian imagination of the theological concept of the communion of saints. He concludes that the embodied witness of the saints themselves, as well as the liturgical and devotional movements of the Church at prayer, testifies to the central importance of the communion of saints as the eschatological hope and fulfillment of the promises of Christ.
Semiconductor devices variability: modelling, characterization and data management
Creators: name: Seoane, Natalia
Publisher: name: Zenodo
Year: 2021
Subjects: TCAD
Compact Modeling

description: The scaling of semiconductor devices leads to larger influence of variability on device performance. Therefore, next generation technology nodes must be based on variability-resistant architectures. TCAD based tools, that include the effect of quantum confinement, are required to assess the impact of variability sources when critical dimensions are below 20 nm. Large ensembles of different device configurations need to be modelled to obtain statistical significance, which greatly increases computational cost and output data. An efficient post-processing of simulation data requires automated tools to extract and analyze the IV characteristic figures-of-merit (FoM). In this workshop, we will introduce in-house-built tools to efficiently model and characterize advanced semiconductor device variability, managing the generated data following the FAIR principles.
An old Einstein - Eddington generalized gravity and modern ideas on branes and cosmology
Creators: name: Filippov, A. T.
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We briefly discuss new models of an `affine' theory of gravity in multidimensional space-times with symmetric connections. We use and generalize Einstein's proposal to specify the space-time geometry by use of the Hamilton principle to determine the connection coefficients from a geometric Lagrangian that is an arbitrary function of the generalized Ricci curvature tensor and of other fundamental tensors. Such a theory supplements the standard Einstein gravity with dark energy (the cosmological constant, in the first approximation), a neutral massive (or tachyonic) vector field vecton, and massive (or tachyonic) scalar fields. These fields couple only to gravity and can generate dark matter and/or inflation. The concrete choice of the geometric Lagrangian determines further details of the theory. The most natural geometric models look similar to recently proposed brane models of cosmology usually derived from string theory.
description: 13 pages
Revised bounds on local cosmic strings from NANOGrav observations
Creators: name: Kume, Jun'ya
name: Hindmarsh, Mark
Publisher: name: arXiv
Year: 2024
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In a recent paper, the NANOGrav collaboration studied new physics explanations of the observed pulsar timing residuals consistent with a stochastic gravitational wave background (SGWB), including cosmic strings in the Nambu-Goto (NG) approximation. Analysing one of current models for the loop distribution, it was found that the cosmic string model is disfavored compared to other sources, for example, super massive black hole binaries (SMBHBs). When both SMBHB and cosmic string models are included in the analysis, an upper bound on a string tension $Gμ\lesssim 10^{-10}$ was derived. However, the analysis did not accommodate results from cosmic string simulations in an underlying field theory, which indicate that at most a small fraction of string loops survive long enough to emit GW. Following and extending our previous study, we suppose that a fraction $f_{\rm NG}$ of string loops follow NG dynamics and emit only GWs, and study the three different models of the loop distribution discussed in the LIGO-Virgo-KAGRA (LVK) collaboration analyses. We re-analyze the NANOGrav 15yrs data with our signal models by using the NANOGrav $\texttt{ENTERPRISE}$ analysis code via the wrapper $\texttt{PTArcade}$. We find that loop distributions similar to LVK Model B and C yield higher Bayes factor than Model A analyzed in the NANOGrav paper, as they can more easily accommodate a blue-tilted spectrum of the observed amplitude. Furthermore, because of the degeneracy of $Gμ$ and $f_{\rm NG}$ in determining the signal amplitude, our posterior distribution extends to higher values of $Gμ$, and in some cases the uppermost value of credible intervals is close to the Cosmic Microwave Background limit $Gμ\lesssim 10^{-7}$. Hence, in addition to the pulsar timing array data, further information about the fraction of long-lived loops in a cosmic string network is required to constrain the string tension.
description: 22 pages, 9 figures; v3: matched to the version published in JCAP
The blogosphere as an excitable social medium: Richter's and Omori's Law in media coverage
Creators: name: Klimek, Peter
name: Bayer, Werner
name: Thurner, Stefan
Publisher: name: arXiv
Year: 2011
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We study the dynamics of public media attention by monitoring the content of online blogs. Social and media events can be traced by the propagation of word frequencies of related keywords. Media events are classified as exogenous - where blogging activity is triggered by an external news item - or endogenous where word frequencies build up within a blogging community without external influences. We show that word occurrences show statistical similarities to earthquakes. The size distribution of media events follows a Gutenberg-Richter law, the dynamics of media attention before and after the media event follows Omori's law. We present further empirical evidence that for media events of endogenous origin the overall public reception of the event is correlated with the behavior of word frequencies at the beginning of the event, and is to a certain degree predictable. These results may imply that the process of opinion formation in a human society might be related to effects known from excitable media.
description: 4 pages, 4 figures
Evaluation of dynamically downscaled near-surface meteorological variables and energy fluxes at three mountain glaciers in British Columbia
Creators: name: Tessema, Mekdes Ayalew
Publisher: name: University of British Columbia
Year: 2018

description: All models of glacier melt, regardless of their complexity, must be forced by observed meteorological fields at or in the vicinity of the glacier in question. In the absence of these observations, the forcing is commonly derived from statistical or dynamical downscaling of low resolution climate reanalysis models. Here we focus on a dynamical downscaling via Weather Research and Forecasting (WRF) model, which has previously showed promising results in simulating a surface energy balance (SEB) at several glacierized terrains. Our goal is to evaluate the WRF downscaling approach at three mountain glaciers in the interior mountains of British Columbia where the automatic weather stations (AWSs) recorded data over several summer seasons. The WRF model, nested within the ERA-Interim global reanalysis produced output fields at 7.5 km and 2.5 km spatial resolution, as well as 1 km resolution for one of the sites. We analyze how closely the WRF model output, at sub-daily and daily temporal resolution, resembles the observed meteorological fields and SEB fluxes needed to assess seasonal surface melt at these glaciers. We find that the model at 2.5 km closely simulates the cumulative seasonal melt (±10% difference) despite large biases in the individual components of the SEB model. Overestimation of the number of clear sky days explains the positive bias in the modeled net shortwave radiation. This positive bias, however, is compensated by a negative bias in the modeled net longwave radiation, and by an underestimation of sensible and latent heat fluxes. The underestimation in the latter two fluxes, calculated from the bulk aerodynamic method, is due to underestimated near-surface wind speeds. Radiative fluxes, which are dominant drivers of seasonal melting, are poorly downscaled with WRF, while successfully simulated by the ERAInterim at the course spatial resolution. Therefore, we advocate that SEB models be directly forced with the output from global climate reanalysis. Finally, simulating turbulent heat fluxes at sloped glacier surfaces remains a major challenge, and the 1-km resolution state-of-the-art WRF model is not yet ready to tackle it.
Schwarzschild Black Hole Surrounded by Perfect Fluid Dark Matter in the presence of Quintessence Matter Field
Creators: name: Hamil, B.
name: Lütfüoğlu, B. C.
Publisher: name: arXiv
Year: 2024
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper, we present an exact solution for a spherically symmetric Schwarzschild black hole surrounded by perfect fluid dark matter (PFDM) in the presence of a quintessence field. We investigate the impact of dark matter on the black hole's thermodynamic and optical properties, as well as its quasinormal modes. Our analysis reveals a critical radius where the heat capacity becomes positive, indicating the thermodynamic stability of the black hole. Notably, this critical radius increases with the dark matter parameter $α$. Additionally, we find that as the effects of dark matter increase, the black hole's shadow radius decreases. Using the WKB approximation, we show that the quasinormal mode spectrum differs from that of a standard Schwarzschild black hole due to the influence of PFDM. Moreover, we demonstrate that as $α$ increases, both the real part and the magnitude of the imaginary part of the quasinormal mode frequencies increase. This suggests that field perturbations decay more rapidly in the presence of PFDM compared to those in a Schwarzschild black hole.
description: 32 pages, 7 Tables, 13 Figures
On the interface polaron formation in organic field-effect transistors
Creators: name: De Filippis, G.
name: Cataudella, V.
name: Fratini, S.
name: Ciuchi, S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A model describing the low density carrier state in an organic single crystal FET with high-$κ$ gate dielectrics is studied. The interplay between charge carrier coupling with inter-molecular vibrations in the bulk of the organic material and the long-range interaction induced at the interface with a polar dielectric is investigated. This interplay is responsible for the stabilization of a polaronic state with an internal structure extending on few lattice sites, at much lower coupling strengths than expected from the polar interaction alone. This effect could give rise to polaron self-trapping in high-$κ$ organic FET's without invoking unphysically large values of the carrier interface interaction.
description: 9 pages, 9 figures
Extracting Universal Corner Entanglement Entropy during the Quantum Monte Carlo Simulation
Creators: name: Da Liao, Yuan
name: Song, Menghan
name: Zhao, Jiarui
name: Meng, Zi Yang
Publisher: name: arXiv
Year: 2024
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computational Physics (physics.comp-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The subleading corner logarithmic corrections in entanglement entropy (EE) are crucial for revealing universal characteristics of the quantum critical points (QCPs), but they are challenging to detect. Motivated by recent developments in the stable computation of EE in (2+1)D quantum many-body systems, we have developed a new method for directly measuring the corner contribution in EE with less computational cost. The cornerstone of our approach is to measure the subtracted corner entanglement entropy (SCEE) defined as the difference between the EEs of subregions with the same boundary length for smooth and cornered boundaries during the sign-problem free quantum Monte Carlo simulation. Our improved method inherently eliminates not only the area law term of EE but also the subleading log-corrections arising from Goldstone modes, leaving the universal corner contribution as the leading term of SCEE with greatly improved data quality. Utilizing this advanced approach, we calculate the SCEE of the bilayer Heisenberg model on both square and honeycomb lattices across their (2+1)D O(3) QCPs with different opening angles on entanglement boundary, and obtain the accurate values of the corresponding universal corner log-coefficients. These findings will encourage further theoretical investigations to access controlled universal information for interacting CFTs at (2+1)D.
description: 9 pages, 10 figures
Unitary N-dilations for tuples of commuting matrices
Creators: name: McCarthy, John E.
name: Shalit, Orr
Publisher: name: arXiv
Year: 2011
Subjects: subject: Functional Analysis (math.FA)
subject: Operator Algebras (math.OA)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 47A20 (Primary), 15A45, 47A57 (Secondary)

description: We show that whenever a contractive $k$-tuple $T$ on a finite dimensional space $H$ has a unitary dilation, then for any fixed degree $N$ there is a unitary $k$-tuple $U$ on a finite dimensional space so that $q(T) = P_H q(U) |_H$ for all polynomials $q$ of degree at most $N$.
description: 11 pages
The HerMES SPIRE submillimeter local luminosity function
Creators: name: Vaccari, M.
name: Marchetti, L.
name: Franceschini, A.
name: Altieri, B.
name: Amblard, A.
name: Arumugam, V.
name: Auld, R.
name: Aussel, H.
name: Babbedge, T.
name: Blain, A.
name: Bock, J.
name: Boselli, A.
name: Buat, V.
name: Burgarella, D.
name: Castro-Rodriguez, N.
name: Cava, A.
name: Chanial, P.
name: Clements, D. L.
name: Conley, A.
name: Conversi, L.
name: Cooray, A.
name: Dowell, C. D.
name: Dwek, E.
name: Dye, S.
name: Eales, S.
name: Elbaz, D.
name: Farrah, D.
name: Fox, M.
name: Gear, W.
name: Glenn, J.
name: Solares, E. A. Gonzalez
name: Griffin, M.
name: Halpern, M.
name: Hatziminaoglou, E.
name: Huang, J.
name: Ibar, E.
name: Isaak, K.
name: Ivison, R. J.
name: Lagache, G.
name: Levenson, L.
name: Lu, N.
name: Madden, S.
name: Maffei, B.
name: Mainetti, G.
name: Mortier, A. M. J.
name: Nguyen, H. T.
name: O'Halloran, B.
name: Oliver, S. J.
name: Omont, A.
name: Page, M. J.
name: Panuzzo, P.
name: Papageorgiou, A.
name: Pearson, C. P.
name: Perez-Fournon, I.
name: Pohlen, M.
name: Rawlings, J. I.
name: Raymond, G.
name: Rigopoulou, D.
name: Rizzo, D.
name: Rodighiero, G.
name: Roseboom, I. G.
name: Rowan-Robinson, M.
name: Portal, M. Sanchez
name: Schulz, B.
name: Scott, Douglas
name: Seymour, N.
name: Shupe, D. L.
name: Smith, A. J.
name: Stevens, J. A.
name: Symeonidis, M.
name: Trichas, M.
name: Tugwell, K. E.
name: Valiante, E.
name: Valtchanov, I.
name: Vigroux, L.
name: Wang, L.
name: Ward, R.
name: Wright, G.
name: Xu, C. K.
name: Zemcov, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Local luminosity functions are fundamental benchmarks for high-redshift galaxy formation and evolution studies as well as for models describing these processes. Determining the local luminosity function in the submillimeter range can help to better constrain in particular the bolometric luminosity density in the local Universe, and Herschel offers the first opportunity to do so in an unbiased way by imaging large sky areas at several submillimeter wavelengths. We present the first Herschel measurement of the submillimeter 0
description: Accepted for publication in the A&A Herschel Special Issue
Discrete Time Crystal Phase as a Resource for Quantum Enhanced Sensing
Creators: name: Yousefjani, Rozhin
name: Sacha, Krzysztof
name: Bayat, Abolfazl
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Discrete time crystals are a special phase of matter in which time translational symmetry is broken through a periodic driving pulse. Here, we first propose and characterize an effective mechanism to generate a stable discrete time crystal phase in a disorder-free many-body system with indefinite persistent oscillations even in finite-size systems. Then we explore the sensing capability of this system to measure the spin exchange coupling. The results show strong quantum-enhanced sensitivity throughout the time crystal phase. As the spin exchange coupling varies, the system goes through a sharp phase transition and enters a non-time crystal phase in which the performance of the probe considerably decreases. We characterize this phase transition as a second-order type and determine its critical properties through a comprehensive finite-size scaling analysis. The performance is independent of the initial states and may even benefit from imperfections in the driving pulse. A simple set of projective measurements can capture the quantum-enhanced sensitivity.
description: Comments are welcome!
Multisensor data fusion for sleep apnea monitoring and classification
Creators: name: Premasiri, Swapna Devdinie
Publisher: name: University of British Columbia
Year: 2019

description: Sleep apnea is the most common type of sleep disorder that is related to breathing, amongst the adult population. Although laboratory polysomnography is the gold standard for the detection of apnea, wearable sleep monitoring devices are preferred due to many reasons such as comfort, monitoring in a familiar sleep environment, accessibility without delay, and low cost. It is important then to extract suitable features for the classification of apneic events as suitable for a wearable sleep monitoring device while maintaining the same accuracy levels as in laboratory polysomnography. This thesis first identifies suitable preprocessing and feature extraction techniques for standard biomedical signals monitored in laboratory polysomnography. Then it develops a feature-extraction technique and designs and implements a neural network for sleep apnea detection and classification of sleep stages. Composite Multiscale Sample Entropy (CMSE) is used as the feature extraction technique, in view of its desirable characteristics. The performance of the developed methodology is evaluated using true clinical data of sleep monitoring. The designed neural networks in the present work is found to have the ability to process and classify apneic events and sleep stages while maintaining the accuracy levels of sleep scoring in clinical polysomnography, which is the existing gold standard of sleep monitoring and scoring. The neural network used for classification of sleep stages may be subsequently incorporated as the input to a neural network for classifying apneic events. In addition, the thesis demonstrates the extent to which each individual signal that is monitored in polysomnography has the ability to independently detect apneic events. This would be useful in the implementation of a portable wearable device with clinical capability for sleep monitoring, which is the end objective of the current project.
(Non) occupational free-living physical activity in crane operators and office workers
Creators: name: Kaja, Kastelic
name: Šarabon Nejc
Publisher: name: Zenodo
Year: 2018

description: Sedentary behavior is a well-known risk factor for several non-communicable diseases. The aim of our study was to investigate sedentary time and physical activity in crane operators and office workers within work and non-work context. Fourteen crane operators and 15 office workers wore activPAL continuously for up to five consecutive working days to obtain sitting/lying, standing and stepping time, objectively. Working time and sleep time were also documented. Both groups spent work hours (72.9 % and 72.9 % for crane operators and office workers, respectively) and non-work hours (60.3 % and 54.1 %) mostly sedentary. Subjects of the two groups (crane operators and office workers, respectively) accumulated 3036 and 3177 steps at work and 6236 and 6181 steps outside work on workdays. No significant (p < .05) changes were found between the two studied occupational groups. Health promotion activities for all sedentary occupations to reduce prolonged sitting time should be encouraged.