cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A High Fraction of Heavily X-ray Obscured Active Galactic Nuclei
Creators: name: Carroll, Christopher M.
name: Ananna, Tonima T.
name: Hickox, Ryan C.
name: Masini, Alberto
name: Assef, Roberto J.
name: Stern, Daniel
name: Chen, Chien-Ting J.
name: Lanz, Lauranne
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present new estimates on the fraction of heavily X-ray obscured, Compton-thick (CT) active galactic nuclei (AGNs) out to a redshift of $z \leq$ 0.8. From a sample of 540 AGNs selected by mid-IR (MIR) properties in observed X-ray survey fields, we forward model the observed-to-intrinsic X-ray luminosity ratio ($R_{L_{\text{X}}}$) with a Markov chain Monte Carlo (MCMC) simulation to estimate the total fraction of CT AGNs ($f_{\text{CT}}$), many of which are missed in typical X-ray observations. We create model $N_{\text{H}}$ distributions and convert these to $R_{L_{\text{X}}}$ using a set of X-ray spectral models. We probe the posterior distribution of our models to infer the population of X-ray non-detected sources. From our simulation we estimate a CT fraction of $f_{\text{CT}}$ = $\text{0.555}^{+\text{0.037}}_{-\text{0.032}}$. We perform an X-ray stacking analysis for sources in Chandra X-ray Observatory fields and find that the expected soft (0.5-2 keV) and hard (2-7 keV) observed fluxes drawn from our model to be within 0.48 and 0.12 dex of our stacked fluxes, respectively. Our results suggests at least 50% of all MIR-selected AGNs, possibly more, are Compton-thick ($N_{\text{H}} \gtrsim$ 10$^{\text{24}}$ cm$^{-\text{2}}$), which is in excellent agreement with other recent work using independent methods. This work indicates that the total number of AGNs is higher than can be identified using X-ray observations alone, highlighting the importance of a multiwavelength approach. A high $f_{\text{CT}}$ also has implications for black hole (BH) accretion physics and supports models of BH and galaxy co-evolution that include periods of heavy obscuration.
description: 14 pages, 6 figures, 1 table, plus appendix figures. Accepted for publication in ApJ
The First Magnetic Fields
Creators: name: Widrow, Lawrence M.
name: Ryu, Dongsu
name: Schleicher, Dominik
name: Subramanian, Kandaswamy
name: Tsagas, Christos G.
name: Treumann, Rudolf A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We review current ideas on the origin of galactic and extragalactic magnetic fields. We begin by summarizing observations of magnetic fields at cosmological redshifts and on cosmological scales. These observations translate into constraints on the strength and scale magnetic fields must have during the early stages of galaxy formation in order to seed the galactic dynamo. We examine mechanisms for the generation of magnetic fields that operate prior during inflation and during subsequent phase transitions such as electroweak symmetry breaking and the quark-hadron phase transition. The implications of strong primordial magnetic fields for the reionization epoch as well as the first generation of stars is discussed in detail. The exotic, early-Universe mechanisms are contrasted with astrophysical processes that generate fields after recombination. For example, a Biermann-type battery can operate in a proto-galaxy during the early stages of structure formation. Moreover, magnetic fields in either an early generation of stars or active galactic nuclei can be dispersed into the intergalactic medium.
description: Accepted for publication in Space Science Reviews. Pdf can be also downloaded from http://canopus.cnu.ac.kr/ryu/cosmic-mag1.pdf
Site selection and design criteria for open air theatre on Prince's Island
Creators: name: Looman, Gerrit Jan
Publisher: name: Environmental Design
Year: 1977
Subjects: subject: NA 6840 C34 L64 1977 Microfiche
subject: Theaters - Construction
subject: Theater, Open-air
subject: Parks, Municipal - Alberta - Calgary

description: Bibliography: p. 136-138.
Field-induced quantum fluctuations in the heavy fermion superconductor CeCu2Ge2
Creators: name: Singh, D. K.
name: Thamizhavel, A.
name: Lynn, J. W.
name: Dhar, S.
name: Rodriguez-Rivera, J.
name: Herman, T.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Quantum-mechanical fluctuations in strongly correlated electron systems cause unconventional phenomena such as non-Fermi liquid behavior, and arguably high temperature superconductivity. Here we report the discovery of a field-tuned quantum critical phenomenon in stoichiometric CeCu2Ge2, a spin density wave ordered heavy fermion metal that exhibits unconventional superconductivity under ~ 10 GPa of applied pressure. Our finding of the associated quantum critical spin fluctuations of the antiferromagnetic spin density wave order, dominating the local fluctuations due to single-site Kondo effect, provide new information about the underlying mechanism that can be important in understanding superconductivity in this novel compound.
description: Heavy Fermion, Quantum Critical Phenomenon
2D and 3D Polar Plume Analysis from the Three Vantage Positions of STEREO/EUVI A, B, and SOHO/EIT
Creators: name: de Patoul, Judith
name: Inhester, Bernd
name: Feng, Li
name: Wiegelmann, Thomas
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: Polar plumes are seen as elongated objects starting at the solar polar regions. Here, we analyze these objects from a sequence of images taken simultaneously by the three spacecraft telescopes STEREO/EUVI A and B, and SOHO/EIT. We establish a method capable of automatically identifying plumes in solar EUV images close to the limb at 1.01 - 1.39 R in order to study their temporal evolution. This plume-identification method is based on a multiscale Hough-wavelet analysis. Then two methods to determined their 3D localization and structure are discussed: First, tomography using the filtered back-projection and including the differential rotation of the Sun and, secondly, conventional stereoscopic triangulation. We show that tomography and stereoscopy are complementary to study polar plumes. We also show that this systematic 2D identification and the proposed methods of 3D reconstruction are well suited, on one hand, to identify plumes individually and on the other hand, to analyze the distribution of plumes and inter-plume regions. Finally, the results are discussed focusing on the plume position with their cross-section area.
description: 22 pages, 10 figures, Solar Physics article
Optimal Estimation of the Binned Mask-Free Power Spectrum, Bispectrum, and Trispectrum on the Full Sky: Scalar Edition
Creators: name: Philcox, Oliver H. E.
Publisher: name: arXiv
Year: 2023
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: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We derive optimal estimators for the two-, three-, and four-point correlators of statistically isotropic scalar fields defined on the sphere, such as the Cosmic Microwave Background temperature fluctuations, allowing for arbitrary (linear) masking and inpainting schemes. In each case, we give the optimal unwindowed estimator (obtained via a maximum-likelihood prescription, with an associated Fisher deconvolution matrix), and an idealized form, and pay close attention to their efficient computation. For the trispectrum, we include both parity-even and parity-odd contributions, as allowed by symmetry. The estimators can include arbitrary weighting of the data (and remain unbiased), but are shown to be optimal in the limit of inverse-covariance weighting and Gaussian statistics. The normalization of the estimators is computed via Monte Carlo methods, with the rate-limiting steps (involving spherical harmonic transforms) scaling linearly with the number of bins. An accompanying code package, PolyBin, implements these estimators in Python, and we demonstrate the estimators' efficacy via a suite of validation tests.
description: 33 pages, 10 figures, code available at https://github.com/oliverphilcox/PolyBin. Accepted by Phys. Rev. D
A Multifrequency approach of the cosmological parameter estimation in presence of extragalactic point sources
Creators: name: Paoletti, D.
name: Aghanim, N.
name: Douspis, M.
name: Finelli, F.
name: De Zotti, G.
name: Lagache, G.
name: Pénin, Aurélie
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a multifrequency approach which optimizes the constraints on cosmological parameters with respect to extragalactic sources and secondary anisotropies contamination on small scales. We model with a minimal number of parameters the expected dominant contaminations in intensity, such as unresolved point sources and the thermal Sunyaev-Zeldovich effect. The model for unresolved point sources, either Poisson distributed or clustered, uses data from Planck early results. The overall amplitude of these contributions are included in a Markov Chain Monte Carlo analysis for the estimate of cosmological parameters. We show that our method is robust: as long as the main contaminants are taken into account the constraints on the cosmological parameters are unbiased regardless of the realistic uncertainties on the contaminants. We show also that the two parameters modelling unresolved points sources are not prior dominated.
description: 17 Pages, 15 Figures, Submitted to MNRAS
Marcus' Case Study: Leading quality research use
Creators: name: Gleeson, Jo
name: Cutler, Blake
name: Hall, Genevieve
name: Rickinson, Mark
name: Walsh, Lucas
Publisher: name: Monash University
Year: 2023
Subjects: Professional education and training
Teacher education and professional development of educators
Educational administration, management and leadership

description: This case study shares the story of Marcus and how he leads quality research use in his role as Assistant Principal, Learning and Teaching, at Malahide College.
 Marcus' case study was developed by the Monash Q Project (2019-2023) and published as part of the resources for the Quality Use of Research Evidence (QURE) Assessment Tool – a confidential online questionnaire enabling educators and education system leaders, as individuals or as a group, to reflect upon and assess their use of research in their practice.
Inclusion statistics and particle condensation in 2 dimensions
Creators: name: Ouvry, Stéphane
name: Polychronakos, Alexios P.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We propose a new type of quantum statistics, which we call inclusion statistics, in which particles tend to coalesce more than ordinary bosons. Inclusion statistics is defined in analogy with exclusion statistics, in which statistical exclusion is stronger than in Fermi statistics, but now extrapolating beyond Bose statistics, resulting in statistical inclusion. A consequence of inclusion statistics is that the lowest space dimension in which particles can condense in the absence of potentials is $d=2$, unlike $d=3$ for the usual Bose-Einstein condensation. This reduction in the dimension happens for any inclusion stronger than bosons, and the critical temperature increases with stronger inclusion. Possible physical realizations of inclusion statistics involving attractive interactions between bosons may be experimentally achievable.
description: 12 pages, 0 figure
Photoluminescence spectroscopy of pure pentacene, perfluoropentacene and mixed thin films
Creators: name: Anger, F.
name: Ossó, J. O.
name: Heinemeyer, U.
name: Broch, K.
name: Scholz, R.
name: Gerlach, A.
name: Schreiber, F.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We report detailed temperature dependent photoluminescence (PL) spectra of pentacene (PEN), perfluoropentacene (PFP), and PEN:PFP mixed thin films grown on SiO2. PEN and PFP are particularly suitable for this study, since they are structurally compatible for good intermixing and form a model donor/acceptor system. The PL spectra of PEN are discussed in the context of existing literature and compared to the new findings for PFP. We analyze the optical transitions observed in the spectra of PEN and PFP using time-dependent density functional theory (TD-DFT) calculations. Importantly, for the mixed PEN:PFP film we observe an optical transition in PL at 1.4 eV providing evidence for coupling effects in the blend. We discuss a possible charge-transfer (CT) and provide a tentative scheme of the optical transitions in the blended films.
description: 9 pages, 6 figures, accepted for publication in J. Chem. Phys
Master formulas for photon amplitudes in a combined constant and plane-wave background field
Creators: name: Schubert, Christian
name: Shaisultanov, Rashid
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The worldline formalism has previously been used for deriving compact master formulas for the QED $N$ - photon amplitudes in vacuum, in a constant field and in a plane-wave field. Here we carry this program one step further by deriving master formulas for the scalar and spinor QED $N$-photon amplitudes in the background of the "parallel" special case of a combined constant and plane-wave field.
description: 20 pages, no figures, typo in eq. (58) corrected
Low temperature spintronics : probing charge and spin states with two-dimensional electron gas
Creators: name: Yu, Wing Wa
Publisher: name: University of British Columbia
Year: 2009

description: This thesis is based on two low temperature experiments in spintronics - physics and engineering of electronic spins. The measurements were performed on a GaAs/AlGaAs two-dimensional electron gas with geometries defined by tunable surface gates. The first experiment is about detection of electrons in a quantum dot. A quantum point contact (QPC) and a quantum wire (QW) is coupled to a single-lead few-electron quantum dot. By measuring the conductance of the QPC and the QW, one can gain information on the average number of electrons in the dot as well as energy-level structure of the dot. The second experiment investigates anisotropy of spin-orbit interaction in GaAs/AlGaAs heterostructure by measuring spin polarization in a narrow channel. Polarized electrons are injected into the channel through a spin-selective injector QPC and diffuse towards the end of the channel. This diffusion generates a pure spin current and the spin polarization 25 microns away is measured by a detector QPC. A periodic spin-orbit field induced by motion of the electrons in the channel causes the spins to resonate with external magnetic field. Spin-orbit anisotropy is demonstrated by the different resonance strength observed in channels aligned along two different crystal axes.
Effusion of stochastic processes on a line
Creators: name: Dean, David S.
name: Majumdar, Satya N.
name: Schehr, Gregory
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We consider the problem of leakage or effusion of an ensemble of independent stochastic processes from a region where they are initially randomly distributed. The case of Brownian motion, initially confined to the left half line with uniform density and leaking into the positive half line is an example which has been extensively studied in the literature. Here we derive new results for the average number and variance of the number of leaked particles for arbitrary Gaussian processes initially confined to the negative half line and also derive its joint two-time probability distribution, both for the annealed and the quenched initial conditions. For the annealed case, we show that the two-time joint distribution is a bivariate Poisson distribution. We also discuss the role of correlations in the initial particle positions on the statistics of the number of particles on the positive half line. We show that the strong memory effects in the variance of the particle number on the positive real axis for Brownian particles, seen in recent studies, persist for arbitrary Gaussian processes and also at the level of two-time correlation functions.
description: 19 pages, 2 figues
Constancy and change: a dramaturgical approch to Chekhov's Uncle Vanya and The Cherry Orchard
Creators: name: Burgoyne, Jocelyn
Publisher: name: University of Calgary
Year: 1979
Subjects: subject: Chekhov, Anton Pavlovich, 1860-1904. The Cherry Orchard
subject: Chekhov, Anton Pavlovich, 1860-1904. Uncle Vanya
subject: Theater - Production and direction

description: Bibliography: p. 142-149.
Measurement requirements for a near-Earth asteroid impact mitigation demonstration mission
Creators: name: Wolters, Stephen D.
name: Ball, Andrew J.
name: Wells, Nigel
name: Saunders, Christopher
name: McBride, Neil
Publisher: name: arXiv
Year: 2011
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: A concept for an Impact Mitigation Preparation Mission, called Don Quijote, is to send two spacecraft to a Near-Earth Asteroid (NEA): an Orbiter and an Impactor. The Impactor collides with the asteroid while the Orbiter measures the resulting change in the asteroid's orbit, by means of a Radio Science Experiment (RSE) carried out before and after impact. Three parallel Phase A studies on Don Quijote were carried out for the European Space Agency: the research presented here reflects outcomes of the study by QinetiQ. We discuss the mission objectives with regards to the prioritisation of payload instruments, with emphasis on the interpretation of the impact. The Radio Science Experiment is described and it is examined how solar radiation pressure may increase the uncertainty in measuring the orbit of the target asteroid. It is determined that to measure the change in orbit accurately a thermal IR spectrometer is mandatory, to measure the Yarkovsky effect. The advantages of having a laser altimeter are discussed. The advantages of a dedicated wide-angle impact camera are discussed and the field-of-view is initially sized through a simple model of the impact.
description: 28 pages
Armleuchter und Nussbügel – neue eisenzeitliche Fibeln aus Westfalen
Creators: name: Grünewald, Christoph
name: Zeiler, Manuel
Publisher: name: Archäologie in Westfalen-Lippe
Year: 2020

description: -
description: Archäologie in Westfalen-Lippe, ARCHÄOLOGIE IN WESTFALEN-LIPPE 2018 (2019)
Quiescence of an Outburst of a Low-Mass Young Stellar Object: LDN1415-IRS
Creators: name: Singh, Koshvendra
name: Ojha, Devendra K.
name: Ninan, Joe P.
name: Sharma, Saurabh
name: Ghosh, Supriyo
name: Ghosh, Arpan
name: Bhatt, Bhuwan C.
name: Sahu, Devendra K.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: LDN1415-IRS, a low-mass young stellar object (YSO) went into an outburst between 2001 and 2006, illuminating a surrounding nebula, LDN1415-Neb. LDN1415-Neb was found to have brightened by I=3.77 mag by April 2006. The optical light curve covering $\sim$ 15.5 years, starting from October 2006 to January 2022, is presented in this study. The initial optical spectrum indicated the presence of winds in the system but the subsequent spectra have no wind indicators. The declining light curve and the absence of the P-Cygni profile in later epoch spectra indicate that the star and nebula system is retrieving back from its outburst state. Two Herbig-Haro objects (HHOs) are positioned linearly with respect to the optical brightness peak of the nebula, probably indicating the circumstellar disk being viewed edge-on. Our recent deep near-infrared (NIR) imaging using TANSPEC has revealed the presence of a nearby star-like source, south of the LDN1415-IRS, at an angular distance of $\sim$ 5.4 arcsec.
description: Accepted for publication in the Journal of Astrophysics and Astronomy
Probing the internal rotation of pre-white dwarf stars with asteroseismology: the case of PG 122+200
Creators: name: Córsico, A. H.
name: Althaus, L. G.
name: Kawaler, S. D.
name: Bertolami, M. M. Miller
name: García--Berro, E.
name: Kepler, S. O.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We put asteroseismological constraints on the internal rotation profile of the GW Vir (PG1159-type) star PG 0122+200. To this end we employ a state-of-the-art asteroseismological model for this star and we assess the expected frequency splittings induced by rotation adopting a forward approach in which we compare the theoretical frequency separations with the observed ones assuming different types of plausible internal rotation profiles. We also employ two asteroseismological inversion methods for the inversion of the rotation profile of PG 0122+200. We find evidence for differential rotation in this star. We demonstrate that the frequency splittings of the rotational multiplets exhibited by PG 0122+200 are compatible with a rotation profile in which the central regions are spinning about 2.4 times faster than the stellar surface.
description: 8 pages, 6 figures, 2 tables. To be published in MNRAS
Photo-electron momentum spectra from minimal volumes: the time-dependent surface flux method
Creators: name: Tao, Liang
name: Scrinzi, Armin
Publisher: name: arXiv
Year: 2011
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The time-dependent surface flux (t-SURFF) method is introduced for computing of strong-field infrared photo-ionization spectra of atoms by numerically solving the time-dependent Schrödinger equation on minimal simulation volumes. The volumes only need to accommodate the electron quiver motion and the relevant range of the atomic binding potential. Spectra are computed from the electron flux through a surface, beyond which the outgoing flux is absorbed by infinite range exterior complex scaling (irECS). Highly accurate infrared photo-electron spectra are calculated in single active electron approximation and compared to literature results. Detailed numerical evidence for performance and accuracy is given. Extensions to multi-electron systems and double ionization are discussed.
description: 18 pages, 5 figures
PyVBMC: Efficient Bayesian inference in Python
Creators: name: Huggins, Bobby
name: Li, Chengkun
name: Tobaben, Marlon
name: Aarnos, Mikko J.
name: Acerbi, Luigi
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: Computation (stat.CO)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: PyVBMC is a Python implementation of the Variational Bayesian Monte Carlo (VBMC) algorithm for posterior and model inference for black-box computational models (Acerbi, 2018, 2020). VBMC is an approximate inference method designed for efficient parameter estimation and model assessment when model evaluations are mildly-to-very expensive (e.g., a second or more) and/or noisy. Specifically, VBMC computes: - a flexible (non-Gaussian) approximate posterior distribution of the model parameters, from which statistics and posterior samples can be easily extracted; - an approximation of the model evidence or marginal likelihood, a metric used for Bayesian model selection. PyVBMC can be applied to any computational or statistical model with up to roughly 10-15 continuous parameters, with the only requirement that the user can provide a Python function that computes the target log likelihood of the model, or an approximation thereof (e.g., an estimate of the likelihood obtained via simulation or Monte Carlo methods). PyVBMC is particularly effective when the model takes more than about a second per evaluation, with dramatic speed-ups of 1-2 orders of magnitude when compared to traditional approximate inference methods. Extensive benchmarks on both artificial test problems and a large number of real models from the computational sciences, particularly computational and cognitive neuroscience, show that VBMC generally - and often vastly - outperforms alternative methods for sample-efficient Bayesian inference, and is applicable to both exact and simulator-based models (Acerbi, 2018, 2019, 2020). PyVBMC brings this state-of-the-art inference algorithm to Python, along with an easy-to-use Pythonic interface for running the algorithm and manipulating and visualizing its results.
description: 6 pages, 1 figure. Published in The Journal of Open Source Software. Documentation is available at https://acerbilab.github.io/pyvbmc and source code is available at https://github.com/acerbilab/pyvbmc
Off-axis digital hologram reconstruction: some practical considerations
Creators: name: Verrier, Nicolas
name: Atlan, Michael
Publisher: name: arXiv
Year: 2011
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Holographic rendering of off-axis intensity digital holograms is discussed. A review of some of the main numerical processing methods, based either on the Fourier transform interpretation of the propagation integral or on its linear system counterpart, is reported. Less common methods such as adjustable magnification reconstruction schemes and Fresnelet decomposition are presented and applied to the digital treatment of off-axis holograms. The influence of experimental parameters on the classical hologram reconstruction methods is assessed, offering guidelines for optimal image rendering regarding the hologram recording conditions.
Numerical modelling of wave propagation phenomena in thermo-poroelastic media via discontinuous Galerkin methods
Creators: name: Bonetti, Stefano
name: Botti, Michele
name: Mazzieri, Ilario
name: Antonietti, Paola F.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 35L05, 65M12, 65M60, 74F05, 76S05

description: We present and analyze a high-order discontinuous Galerkin method for the space discretization of the wave propagation model in thermo-poroelastic media. The proposed scheme supports general polytopal grids. Stability analysis and $hp$-version error estimates in suitable energy norms are derived for the semi-discrete problem. The fully-discrete scheme is then obtained based on employing an implicit Newmark-$β$ time integration scheme. A wide set of numerical simulations is reported, both for the verification of the theoretical estimates and for examples of physical interest. A comparison with the results of the poroelastic model is provided too, highlighting the differences between the predictive capabilities of the two models.
Improved DWT Based Watermarking Using JPEG-YCbCr
Creators: name: Khalili, Mehdi
name: Asatryan, David
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cryptography and Security (cs.CR)
subject: Multimedia (cs.MM)
subject: FOS: Computer and information sciences
subject: D.4.6; K.6.5; K.4.2
subject: 68U10, 68U20, 65C20, 94A08, 94A24, 94A60, 11T71, 14G50, 68P25, 81P94

description: In this paper a blind, Secure, imperceptible and robust watermarking algorithm based on wavelet transform domain is proposed in which for more security, the watermark W is converted to a sequence and then a random binary sequence R of size n is adopted to encrypt the watermark, where n is the size of the watermark image. Afterwards, the encrypted watermark sequence W1 is generated by executing exclusive-OR operation on W and R. This generated watermark embeds into low frequency selected coefficients of Y channel wavelet decomposition of JPEG-YCbCr using LSB insertion technique. The experimental results show that the proposed algorithm increases the security and imperceptibility of watermark and has better robustness against wavelet compression and cropping attacks compared to the earlier work in [1].
description: 4 Pages, 5 Figures, 3 Tables
Fully conservative $f(R,T)$ gravity and Solar System constraints
Creators: name: Bertini, Nicolas R.
name: Velten, Hermano
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The $f(R,T)$ gravity is a model whose action contains an arbitrary function of the Ricci scalar $R$ and the trace of the energy-momentum tensor $T$. We consider the separable model $f (R, T ) = χ(R) + φ(T )$ and shown that, for perfect fluids, the dynamical equations are sufficient to determine how $φ$ depends on $T$, independently of the matter state equation and the geometry of space-time. Imposing the energy-momentum tensor conservation we obtain that $φ$ must be linear in $T$. However, the $T$ dependence is severely constrained using the full Will-Nordtvedt version of the parameterized post-Newtonian (PPN) formalism. The result of the PPN analysis is discussed and in addition it is shown that the diffeomorphism invariance of the matter action imposes strong constraints on conservative versions of $f(R,T)$ gravity.
description: 15 pages, thirteen references added and text improvements. Typos corrected. Accepted in PRD
Mittelalterlicher Bergbau im Stadtgebiet Brilons
Creators: name: Zeiler, Manuel
name: Schröder, Hilmar
name: Weber, Heinz-Werner
Publisher: name: Archäologie in Westfalen-Lippe
Year: 2020

description: -
description: Archäologie in Westfalen-Lippe, ARCHÄOLOGIE IN WESTFALEN-LIPPE 2018 (2019)
Revisiting Vainshtein Screening for fast N-body simulations
Creators: name: Brando, Guilherme
name: Koyama, Kazuya
name: Winther, Hans A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We revisit a method to incorporate the Vainshtein screening mechanism in N-body simulations proposed by R. Scoccimarro in~\cite{Scoccimarro:2009eu}. We further extend this method to cover a subset of Horndeski theories that evade the bound on the speed of gravitational waves set by the binary neutron star merger GW170817. The procedure consists of the computation of an effective gravitational coupling that is time and scale dependent, $G_{\rm eff}\left(k,z\right)$, where the scale dependence will incorporate the screening of the fifth-force. This is a fast procedure that when contrasted to the alternative of solving the full equation of motion for the scalar field inside N-body codes, reduces considerably the computational time and complexity required to run simulations. To test the validity of this approach in the non-linear regime, we have implemented it in a COmoving Lagrangian Approximation (COLA) N-body code, and ran simulations for two gravity models that have full N-body simulation outputs available in the literature, nDGP and Cubic Galileon. We validate the combination of the COLA method with this implementation of the Vainshtein mechanism with full N-body simulations for predicting the boost function: the ratio between the modified gravity non-linear matter power spectrum and its General Relativity counterpart. This quantity is of great importance for building emulators in beyond-$Λ$CDM models, and we find that the method described in this work has an agreement of below $2\%$ for scales down to $k \approx 3h/$Mpc with respect to full N-body simulations.
description: 33 pages, 13 figures and 9 tables. JCAP accepted version
Are OPERA neutrinos faster than light because of non-inertial reference frames?
Creators: name: Germana, Claudio
Publisher: name: arXiv
Year: 2012
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Recent results from the OPERA experiment reported a neutrino beam traveling faster than light. The experiment measured the neutrino time of flight (TOF) over a baseline from the CERN to the Gran Sasso site. The neutrino beam arrives 60 ns earlier than a light ray would do. Because the result has an enormous impact on science, it might be worth double-checking the time definitions with respect to the non-inertial system in which the neutrino travel time was measured. Potential problems in the OPERA data analysis connected with the definition of the reference frame and time synchronization are emphasized. We aim to investigate the synchronization of non-inertial clocks on Earth by relating this time to the proper time of an inertial observer at Solar System Barycenter(SSB). The Tempo2 software was used to time-stamp events observed on the geoid with respect to the SSB inertial observer time. Neutrino results from OPERA might carry the fingerprint of non-inertial effects. The CERN-Gran Sasso clock synchronization is accomplished by applying corrections that depend on special and general relativistic time dilation effects at the clocks, depending on the position of the clocks in the solar system gravitational well. As a consequence, TOF distributions are centered on values shorter by tens of ns than expected, integrating over a period from April to December, longer if otherwise. It is worth remarking that the OPERA runs have always been carried out from April/May to November. If the analysis by Tempo2 holds for the OPERA experiment, the excellent measurement by the OPERA collaboration will turn into a proof of the General Relativity theory in a weak field approximation. The analysis presented here is falsifiable because it predicts that performing the experiment from January to March/April, the neutrino beam will be detected to arrive 50 ns later than light.
description: 5 pages, 4 figures, accepted for publication in Astronomy and Astrophysics Letters
Angular correlation of the two gamma rays produced in the thermal neutron capture on gadolinium-155 and gadolinium-157
Creators: name: Goux, Pierre
name: Glessgen, Franz
name: Gazzola, Enrico
name: Reen, Mandeep Singh
name: Focillon, William
name: Gonin, Michel
name: Tanaka, Tomoyuki
name: Hagiwara, Kaito
name: Ali, Ajmi
name: Sudo, Takashi
name: Koshio, Yusuke
name: Sakuda, Makoto
name: Collazuol, Gianmaria
name: Kimura, Atsushi
name: Nakamura, Shoji
name: Iwamoto, Nobuyuki
name: Harada, Hideo
name: Wurm, Michael
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: The ANNRI-Gd collaboration studied in detail the single $γ$-ray spectrum produced from the thermal neutron capture on $^{155}$Gd and $^{157}$Gd in our previous publications. Gadolinium targets were exposed to a neutron beam provided by the Japan Spallation Neutron Source (JSNS) in J-PARC, Japan. In the present analysis, one new additional coaxial germanium crystal was used in the analysis in combination with the fourteen germanium crystals in the cluster detectors to study the angular correlation of the two $γ$ rays emitted in the same neutron capture. We present for the first time angular correlation functions for two $γ$ rays produced during the electromagnetic cascade transitions in the (n, $γ$) reactions on $^{\rm 155}$Gd and $^{\rm 157}$Gd. As expected, we observe the mild angular correlations for the strong, but rare transitions from the resonance state to the two energy levels of known spin-parities. Contrariwise, we observe negligibly small angular correlations for arbitrary pairs of two $γ$ rays produced in the majority of cascade transitions from the resonance state to the dense continuum states.
description: 21 pages, 13 figures
Bau- und Kriegshandwerk Mitte des 13. Jahrhunderts – die Burg auf dem Schildberg bei Lügde
Creators: name: Müller-Kissing, Johannes
Publisher: name: Archäologie in Westfalen-Lippe
Year: 2020

description: -
description: Archäologie in Westfalen-Lippe, ARCHÄOLOGIE IN WESTFALEN-LIPPE 2018 (2019)
Measurement of the Transverse Single Spin Asymmetry of $p$ + $p^\uparrow$ $\rightarrow$ $η$ + $X$ at $\sqrt{s}$ = 200 GeV
Creators: name: Kleinjan, David
Publisher: name: arXiv
Year: 2012
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The measurement of transverse single spin asymmetries ($A_N$) provides insight into the structure of the nucleon. Several mechanisms have been proposed that attempt to explain $A_N$ based on QCD, and additional measurements of $A_N$ for different processes further constrain these models. Using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC), we study transversely polarized p+p collisions. Results from PHENIX and other experiments show significant asymmetries in the forward region, which could be due to contributions from both the Sivers and the Collins effects. Studying the species as well as the kinematic dependencies of these transverse single spin asymmetries will help to disentangle the origin of the observed asymmetries. Therefore, measurements of $A_N$ with inclusive $η$ mesons at forward rapidities are an important tool for the understanding of these asymmetries. In 2008, the PHENIX experiment collected 5.2 pb$^{-1}$ integrated luminosity in $p^\uparrow+p$ collisions at $\sqrt{s}$ = 200 GeV. The status of the asymmetry analysis of $η$ mesons at forward rapidity will be shown.
description: 4 pages, 3 figures
Seltener Bodentyp in Höxter durch 800 Jahre Gartennutzung
Creators: name: Deppe, Albrecht
name: König, Andreas
Publisher: name: Archäologie in Westfalen-Lippe
Year: 2020

description: -
description: Archäologie in Westfalen-Lippe, ARCHÄOLOGIE IN WESTFALEN-LIPPE 2018 (2019)
Surface loading and rigid indentation of an elastic layer with surface energy effects
Creators: name: Zhao, Xujun
Publisher: name: University of British Columbia
Year: 2009

description: With the growing interest in nanotechnology, it is becoming important to understand the nanoscale mechanics to achieve successful design and fabrication of nanoscale devices. However, the classical continuum theory is not directly applicable to the analysis of nanoscale domains due to size-dependent behavior of nanostructures. Since the surface-to-volume ratio of a nanoscale domain is relatively high compared to that of a macro-scale domain, the energy associated with atoms at or near a free surface is different from that of atoms in the bulk. The effect of surface free energy therefore needs to be considered. Ultra-thin film/substrate systems, which are encountered in applications involving nanocoatings, nanotribology and material characterization based on nano-indentation, may be analyzed using modified continuum elasticity theory incorporating surface energy effects. This thesis presents a set of analytical solutions for elastic field of a layer of nanoscale thickness bonded to a rigid base under surface loading and indentation by a rigid body. Surface energy effects are accounted for by using Gurtin-Murdoch elasticity theory. Fourier and Hankel integral transforms are used to solve the two- and three- dimensional boundary-value problems involving non-classical boundary conditions associated with the generalized Young-Laplace equation. In the case of a two-dimensional semi-infinite medium, the solutions can be expressed in closed form. The elastic field is found to depend on the layer thickness and surface elastic constants, and the influence of surface energy is shown to be more significant under a horizontal load than under a vertical load. A characteristic length scale related to the surface material properties can be identified for the present class of problems. The solution for the indentation problem is considered for flat, conical and spherical rigid indenters. The mixed boundary-value problem corresponding to a rigid indenter is formulated in terms of a dual integral equation system that is solved by using numerical quadrature. Selected numerical results are presented to show the influence of the indenter shape, surface properties and size-dependency of response.
Das Coesfelder Jesuitenkloster und sein Umfeld
Creators: name: Koppelmann, Sarah
name: Wegener, Kim
Publisher: name: Archäologie in Westfalen-Lippe
Year: 2020

description: -
description: Archäologie in Westfalen-Lippe, ARCHÄOLOGIE IN WESTFALEN-LIPPE 2018 (2019)
Leben und Sterben zwischen Werse und Ems – Ausgrabungen in Münster-Handorf
Creators: name: Markus, Jan
name: Stamer, Simon
Publisher: name: Archäologie in Westfalen-Lippe
Year: 2020

description: -
description: Archäologie in Westfalen-Lippe, ARCHÄOLOGIE IN WESTFALEN-LIPPE 2018 (2019)
Multiple Magnetic Structures of Correlated Ce-ions in Intermetallic CeAu2Ge2
Creators: name: Singh, D. K.
name: Thamizhavel, A.
name: Lynn, J. W.
name: Dhar, S. K.
name: Hermann, T.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Neutron diffraction measurements on a high quality single crystal of CeAu2Ge2 reveal two new magnetic structures that coexist with commensurate long range antiferromagnetic order below the Neel temperature T_N ~ 14 K. The new magnetic structures, which exhibit distinct temperature and field dependencies, are described by both commensurate and incommensurate magnetic structures and introduces new region in the H-T phase diagram. These new experimental observations provide essential information for developing a universal understanding of the magnetic properties of this class of Ce-based CeX2M2 (X = Cu, Ag, Au; M = Ge, Si) compounds, which are prototypes for exploring quantum phase transitions and their interplay with unconventional superconductivity.
description: Heavy fermion
Electrical conductivity and thermal dilepton rate from quenched lattice QCD
Creators: name: Kaczmarek, Olaf
name: Francis, Anthony
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We report on a continuum extrapolation of the vector current correlation function for light valence quarks in the deconfined phase of quenched QCD. This is achieved by performing a systematic analysis of the influence of cut-off effects on light quark meson correlators at $T\simeq 1.45 T_c$ using clover improved Wilson fermions. We discuss resulting constraints on the electrical conductivity and the thermal dilepton rate in a quark gluon plasma. In addition new results at 1.2 and 3.0 $T_c$ will be presented.
description: 4 pages, 6 eps figures, to appear in the proceedings of Quark Matter 2011, 23-28 May 2011, Annecy, France
Im Schatten der Domburg – 2200 Jahre Siedlungsgeschichte im Paderborner Stadtkern
Creators: name: Gai, Sveva
name: Mahytka, Ralf
name: Otte, Ralf
Publisher: name: Archäologie in Westfalen-Lippe
Year: 2020

description: -
description: Archäologie in Westfalen-Lippe, ARCHÄOLOGIE IN WESTFALEN-LIPPE 2018 (2019)
Entdeckung eines Wehrmachtsstollens unter dem Höxterschen Gymnasium
Creators: name: Müller-Kissing, Johannes
Publisher: name: Archäologie in Westfalen-Lippe
Year: 2020

description: -
description: Archäologie in Westfalen-Lippe, ARCHÄOLOGIE IN WESTFALEN-LIPPE 2018 (2019)
Bleistift und 3-D-Modell – Kombination neuer und klassischer Dokumentationsmethoden
Creators: name: Hessel, Peter
name: Markus, Jan
name: Leonhard, Gordon
Publisher: name: Archäologie in Westfalen-Lippe
Year: 2020

description: -
description: Archäologie in Westfalen-Lippe, ARCHÄOLOGIE IN WESTFALEN-LIPPE 2018 (2019)
Ideologie und Organisation
Creators: name: Baumgartner, Catharina
name: Heindl, Patrizia
name: Lindner, Marie-Hélène
name: Preisigke-Borsian, Julia
name: Schlüter, Sarah
Publisher: name: Distant Worlds Journal
Year: 2020

description: Distant Worlds Journal, Nr. 5 (2020): Ideologie und Organisation: Komparative Untersuchungen antiker Gesellschaften
Accreting neutron stars: composition of the upper layers of the inner crust
Creators: name: Shchechilin, Nikolay N.
name: Gusakov, Mikhail E.
name: Chugunov, Andrey I.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We model the nuclear evolution of an accreted matter as it sinks toward the stellar center, in order to find its composition and equation of state. To this aim, we developed a simplified reaction network that allows for redistribution of free neutrons in the inner crust to satisfy the recently suggested neutron hydrostatic and diffusion equilibrium condition. We analyse the main reaction pathways for the three representative thermonuclear ash compositions: Superburst, Kepler, and Extreme rp. In contrast to the previous results, which neglect redistribution of free (unbound) neutrons in the inner crust, the most significant reactions in our calculations are neutron captures and electron emissions. The pycnonuclear fusion plays some role only for Kepler ashes. For the direct application of our results in astrophysical codes we present profiles of the average charge, $\langle Z\rangle$, impurity parameter, $Q_\mathrm{imp}$ and equation of state for a set of models, parametrized by the pressure at the outer-inner crust interface. Typically, for Superburst ashes $Q_\mathrm{imp}\approx 1-4$, while for Kepler ashes $Q_\mathrm{imp}$ decreases from $\approx23$ at the outer-inner crust interface to $\approx5$ at the end of our simulation (the corresponding density equals $ρ_\mathrm{dc}\approx2\times 10^{12}$ g cm$^{-3}$). At the same time, for Extreme rp ashes $Q_\mathrm{imp}$ remains large $\approx 30-35$ in the considered inner crust region. Our results are important for modeling the thermal relaxation of transiently accreting neutron stars after the end of the outburst.
description: 11 pages, 4 figures. Submitted to MNRAS
High energy emission of symbiotic recurrent novae: RS Ophiuchi and V407 Cygni
Creators: name: Hernanz, Margarita
name: Tatischeff, Vincent
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Recurrent novae occurring in symbiotic binaries are candidate sources of high energy photons, reaching GeV energies. Such emission is a consequence of particle acceleration leading to pion production. The shock between matter ejected by the white dwarf, undergoing a nova explosion, and the wind from the red giant companion is responsible for such a process, which mimics a supernova remnant but with much smaller energetic output and much shorter time scales. Inverse Compton can also be responsible for high energy emission. Recent examples are V407 Cyg, detected by Fermi, and RS Oph, which unfortunately exploded in 2006, before Fermi was launched.
description: 6 pages, 4 figures; to appear in the proceedings of the Asiago Workshop on Symbiotic Stars, A. Siviero and U. Munari eds., Baltic Astronomy special issue