cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Analyzing the magnetic influence on magneto-optical interactions
Creators: name: Estrada, Francisco
name: Holanda, José
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Here, we study the magneto-optical interactions in magnetic structures considering the dependence of the interactions with the magnetic field. We perform numerical simulations in a structure of magnetic nanowires, considering them as one chain of strongly interacting single-domain particles. Robustly, we obtain a quantitative value for the interactions, which allows us to classify them into two magnetic states: demagnetized and magnetized.
Nonlinear dielectric response of Debye, alpha, and beta relaxation in 1-propanol
Creators: name: Bauer, Th.
name: Michl, M.
name: Lunkenheimer, P.
name: Loidl, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We present nonlinear dielectric measurements of glass-forming 1-propanol, a prototypical example for the monohydroxy alcohols that are known to exhibit unusual relaxation dynamics, namely an additional Debye relaxation, slower than the structural alpha relaxation. Applying high ac fields of 468 kV/cm allows for a detailed investigation of the nonlinear properties of all three relaxation processes occurring in 1-propanol, namely the Debye, alpha, and beta relaxation. Both the field-induced variations of dielectric constant and loss are reported. Polarization saturation and the absorption of field energy govern the findings in the Debye-relaxation regime, well consistent with the suggested cluster-like nature of the relaxing entities. The behavior of the alpha relaxation is in good accord with the expectations for a heterogeneous relaxation scenario. Finally, the Johari-Goldstein beta-relaxation in 1-propanol seems to exhibit no or only weak field dependence, in agreement with recent findings for the excess wing of canonical glass formers.
description: 8 pages, 4 figures
Durability of Alkali activated concrete made using multiple precursors as primary binders
Creators: name: Al-Duais, Ibrahim N. A.
name: Ahmad, Shamsad
name: Al-Osta, Mohammed A.
name: Maslehuddin, Mohammed
name: Ibrahim, Mohammed
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biophysics
subject: Space Science
subject: Pharmacology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences

description: Alkali-activated binders (AABs) have been and continue to be extensively explored as an alternative to ordinary Portland cement (OPC), addressing environmental and sustainability issues. A large number of studies that were conducted earlier focused mainly on the mechanical properties and some durability aspects of industrial waste-based AABs. However, chloride migration and diffusion causing reinforcement corrosion in AAB-based concrete (AAC) have not been thoroughly investigated. The present study focuses on the durability of AAC produced using multiple precursors that included industrial waste materials and natural minerals such as limestone powder (LSP), red mud (RM), silicomanganese fume (SMF), and natural pozzolan (NP) activated by alkali. Firstly, the dosages of all four precursors were optimized through trials and then NP was partially replaced by 10, 20 and 30% OPC to enhance the performance of the AABs. The AAC mixtures were prepared and cured under different conditions and tested for compressive strength and durability characteristics related to chloride permeability, chloride migration, chloride diffusion, and chloride-induced reinforcement corrosion to evaluate the performances of the mixtures. The results show that the composition of the AABs and curing regimes significantly influenced the performance of the AAC. The inclusion of the OPC resulted in a very significant enhancement of the strength and durability characteristics of the AAC. In addition, there is a sharp increase in the performance of the AAC mixtures when the OPC content of the precursor was increased from 10 to 20%, irrespective of the curing method. Therefore, an optimum dosage of the OPC in the precursor can be considered as 20%, allowing utilization of 80% waste materials and natural minerals as the precursor with much higher strength and durability characteristics than traditional OPC concrete, thus saving energy and reducing environmental pollution leading to a cleaner production of concrete. Lastly, electrochemically measured corrosion potential (Ecorr) and corrosion current density (Icorr) values for the reinforcing bars (rebars) embedded in AAC mixtures were found to be misleading, as confirmed by visual inspection of the extracted rebars in addition to gravimetric test results. Hence, there is a need for further research to develop corrective measures before the utilization of the electrochemical-reinforced corrosion monitoring methods in the case of AACs.
Silicene-based DNA Nucleobase Sensing
Creators: name: Sadeghi, Hatef
name: Bailey, S.
name: Lambert, Colin J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: We propose a DNA sequencing scheme based on silicene nanopores. Using first principles theory, we compute the electrical properties of such pores in the absence and presence of nucleobases. Within a two-terminal geometry, we analyze the current-voltage relation in the presence of nucleobases with various orientations. We demonstrate that when nucleobases pass through a pore, even after sampling over many orientations, changes in the electrical properties of the ribbon can be used to discriminate between bases.
Special Care Dentistry & Co-Located Oral Health Models of Care: A Scoping Review
Creators: name: Legge, Kerry
name: Kong, Ariana
name: Norrie, Tiffany
name: Holden, Alexander
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Medicine and Health Sciences
subject: co-located
subject: dental
subject: dental practitioner
subject: dentistry
subject: disability
subject: integration
subject: oral health care
subject: scoping review
subject: special care
subject: special needs

description: Protocol for a scoping review that aims to map the available evidence on existing or potential oral health models of care that explore the provision of co-located care among people with special needs.
Lagrangian approach to the semi-relativistic electron dynamics in the mean-field approximation
Creators: name: Dixit, Anant
name: Hinschberger, Yannick
name: Zamanian, Jens
name: Manfredi, Giovanni
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We derive a mean-field model that is based on a two-component Pauli-like equation and incorporates quantum, spin, and relativistic effects up to second order in $1/c$. Using a Lagrangian approach, we obtain the self-consistent charge and current densities that act as sources in the Maxwell equations. A physical interpretation is provided for the second-order corrections to the sources. The Maxwell equations are also expanded to the same order. The resulting self-consistent model constitutes a suitable semi-relativistic approximation to the full Dirac-Maxwell equations.
Near-infrared and Optical Nebular-phase Spectra of Type Ia Supernovae SN 2013aa and SN 2017cbv in NGC 5643
Creators: name: Kumar, Sahana
name: Hsiao, Eric Y.
name: Ashall, Chris
name: Phillips, Mark M.
name: Morrell, Nidia
name: Hoeflich, Peter
name: Burns, Chris R.
name: Galbany, Lluis
name: Baron, Eddie
name: Contreras, Carlos
name: Davis, Scott
name: Diamond, Tiara
name: Forster, Francisco
name: Graham, Melissa L.
name: Karamehmetoglu, Emir
name: Kirshner, Robert P.
name: Koribalski, Baerbel
name: Krisciunas, Kevin
name: Lu, Jing
name: Marion, G. H.
name: Pessi, Priscila J.
name: Piro, Anthony L.
name: Shahbandeh, Melissa
name: Stritzinger, Maximillian D
name: Suntzeff, Nicholas B.
name: Uddin, Syed A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present multi-wavelength time-series spectroscopy of SN 2013aa and SN 2017cbv, two Type Ia supernovae (SNe Ia) on the outskirts of the same host galaxy, NGC 5643. This work utilizes new nebular-phase near-infrared (NIR) spectra obtained by the Carnegie Supernova Project-II, in addition to previously published optical and NIR spectra. By measuring nebular-phase [Fe II] lines in both the optical and NIR, we examine the explosion kinematics and test the efficacy of several emission line fitting techniques commonly used in the literature. The NIR [Fe II] 1.644 $μ$m line provides the most robust velocity measurements against variations due to the choice of the fit method and line blending. The resulting effects on velocity measurements due to choosing different fit methods, initial fit parameters, continuum and line profile functions, and fit region boundaries were also investigated. The NIR [Fe II] velocities yield the same radial shift direction as velocities measured using the optical [Fe II] 7155 A line, but the sizes of the shifts are consistently and substantially lower, pointing to a potential issue in optical studies. The NIR [Fe II] 1.644 $μ$m emission profile shows a lack of significant asymmetry in both SNe Ia, and the observed low velocities elevate the importance for correcting for any radial velocity contribution from the host galaxy's rotation. The low [Fe II] velocities measured in the NIR at nebular phases disfavors most progenitor scenarios in close double-degenerate systems for both SN 2013aa and SN 2017cbv. The time evolution of the NIR [Fe II] 1.644 $μ$m line also indicates moderately high progenitor white dwarf central density and potentially high magnetic fields. These sibling SNe Ia were well observed at both early and late times, providing an excellent opportunity to study the intrinsic diversity of SNe Ia.
description: submitted to ApJ on Oct 4, 2022 accepted for publication on Dec 19, 2022
A Unifying Framework for Structural Properties of CSPs: Definitions, Complexity, Tractability
Creators: name: Bordeaux, Lucas
name: Cadoli, Marco
name: Mancini, Toni
Publisher: name: arXiv
Year: 2014
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: Literature on Constraint Satisfaction exhibits the definition of several structural properties that can be possessed by CSPs, like (in)consistency, substitutability or interchangeability. Current tools for constraint solving typically detect such properties efficiently by means of incomplete yet effective algorithms, and use them to reduce the search space and boost search. In this paper, we provide a unifying framework encompassing most of the properties known so far, both in CSP and other fields literature, and shed light on the semantical relationships among them. This gives a unified and comprehensive view of the topic, allows new, unknown, properties to emerge, and clarifies the computational complexity of the various detection problems. In particular, among the others, two new concepts, fixability and removability emerge, that come out to be the ideal characterisations of values that may be safely assigned or removed from a variables domain, while preserving problem satisfiability. These two notions subsume a large number of known properties, including inconsistency, substitutability and others. Because of the computational intractability of all the property-detection problems, by following the CSP approach we then determine a number of relaxations which provide sufficient conditions for their tractability. In particular, we exploit forms of language restrictions and local reasoning.
title: Efficacy of Elder Support and Education on Measles Vaccination Rates in Amish Communities
Creators: name: Porter, Amber
name: Mariateresa, Alfaro
name: Marietta, Lan
name: Schriver, Kristen
name: Douglas, Michelle
name: Lozy, Bonnie
name: Burgos, Emily
Publisher: name: Old Dominion University Libraries
Year: 2017

description: Background: Proposed study within Amish community to increase measles vaccinations and education about measles: etiology and transmission, aseptic techniques, and quarantine/isolation.

Significance: The majority of Amish people are unvaccinated. Massive outbreaks of measles (363 cases in Ohio) within Amish communities.

Method: Non-random, convenience sampling of participants in two Amish communities: Indiana and Illinois.

Analysis: Closed-ended questions with nominal data. Biological measurements with integral data. Qualitative analysis, chi square and statistical analysis used to determine outcome and results.
Symmetry-Resolved Entanglement of $C_2$-symmetric Topological Insulators
Creators: name: Monkman, K.
name: Sirker, J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: For a many-body system of arbitrary dimension, we consider fermionic ground states of non-interacting Hamiltonians invariant under a $C_2$ cyclic group. The absolute difference $Δ$ between the number of occupied symmetric and anti-symmetric single-particle states is an adiabatic invariant. We prove lower bounds on the configurational and the number entropy based on this invariant. In band insulators, the topological invariant $Δ$ and the entropy bounds can be directly determined from high symmetry points in the Brillouin zone.
Faraday scaling and the Bicep2 observations
Creators: name: Giovannini, Massimo
Publisher: name: arXiv
Year: 2014
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: As repeatedly speculated in the past, the linear polarization of the Cosmic Microwave Background can be rotated via the Faraday effect. An economic explanation of the recent Bicep2 observations, not relying on long-wavelength tensor modes of the geometry, would stipulate that the detected B mode comes exclusively from a Faraday rotated E mode polarization. We show hereunder that this interpretation is ruled out by the existing upper limits on the B mode polarization obtained by independent experiments at observational frequencies much lower than the operating frequency of the Bicep2 experiment. We then derive the fraction of the observed B mode polarization ascribable to the Faraday effect and suggest a dedicated experimental strategy for its detection.
description: 8 pages, no figures
REVIEWS: Aldbury, the open village: a portrait of country life, by Jean Davis; Aylesbury remembered: Conversations with Aylesbury people, the Aylesbury Past project; Buckinghamshire Probate Inventories 1661-1714, edited by Michael Reed; Fawley, Buckinghamshire, by Geoffrey Tyack
Creators: name: Baines, Arnold H J
name: Chenevix Trench, John
name: Andrew, Martin
Publisher: name: Archaeology Data Service
Year: 2023

description: Records of Buckinghamshire, 29, 231-235
Reviews: Before Domesday: Haddenham and Cuddington; No ordinary tourist: The travels of an errant duke; Mansions and mud houses: The story of the Penn and Tylers Green Conservation Area
Creators: name: Gulland, Peter
name: Clarke, John
name: Toplis, Ian
Publisher: name: Archaeology Data Service
Year: 2023

description: Records of Buckinghamshire, 48, 286-289
Quantum Gravity, Dynamical Phase Space and String Theory
Creators: name: Freidel, Laurent
name: Leigh, Robert G.
name: Minic, Djordje
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In a natural extension of the relativity principle we argue that a quantum theory of gravity involves two fundamental scales associated with both dynamical space-time as well as dynamical momentum space. This view of quantum gravity is explicitly realized in a new formulation of string theory which involves dynamical phase space and in which space-time is a derived concept. This formulation naturally unifies symplectic geometry of Hamiltonian dynamics, complex geometry of quantum theory and real geometry of general relativity. The space-time and momentum space dynamics, and thus dynamical phase space, is governed by a new version of the Renormalization Group.
description: 9 pages. Essay written for the Gravity Research Foundation 2014 Awards for Essays on Gravitation - honorable mention
Large orbital magnetic moment in VI3
Creators: name: Hovancik, David
name: Piamonteze, Cinthia
name: Pospisil, Jiri
name: Carva, Karel
name: Sechovsky, Vladimir
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The existence of the V3+ ion orbital moment is the open issue of the nature of magnetism in the van der Waals ferromagnet VI3. The huge magnetocrystalline anisotropy in conjunction with the significantly reduced ordered magnetic moment compared to the spin-only value provides strong but indirect evidence of a significant V orbital moment. We used the unique capability of X-ray magnetic circular dichroism to determine the orbital component of the total magnetic moment and provide for the first time a direct proof of an exceptionally sizable orbital moment of the V3+ ion in VI3. Our ligand field multiplet simulations of the XMCD spectra in synergy with the results of DFT calculations agree with the existence of two V sites with different orbital occupations and therefore different OM magnitudes in the ground state.
REVIEWS: Bernwood: The life and afterlife of a forest, by John Broad and Richard Hoyle; Chesham Shuttle: The story of a Metropolitan branch line, by Clive Foxell; Chequers, by Norma Major
Creators: name: Baines, Arnold H J
name: Gulland, Peter
name: Chenevix Trench, John
Publisher: name: Archaeology Data Service
Year: 2023

description: Records of Buckinghamshire, 38, 262-265
A $Chandra-Swift$ View of Point Sources in Hickson Compact Groups: High AGN fraction but a dearth of strong AGNs
Creators: name: Tzanavaris, P.
name: Gallagher, S. C.
name: Hornschemeier, A. E.
name: Fedotov, K.
name: Eracleous, M.
name: Brandt, W. N.
name: Desjardins, T. D.
name: Charlton, J. C.
name: Gronwall, C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present $Chandra$ X-ray point source catalogs for 9 Hickson Compact Groups (HCGs, 37 galaxies) at distances $34 - 89$ Mpc. We perform detailed X-ray point source detection and photometry, and interpret the point source population by means of simulated hardness ratios. We thus estimate X-ray luminosities ($L_X$) for all sources, most of which are too weak for reliable spectral fitting. For all sources, we provide catalogs with counts, count rates, power-law indices ($Γ$), hardness ratios, and $L_X$, in the full ($0.5-8.0$ keV), soft ($0.5-2.0$ keV) and hard ($2.0-8.0$ keV) bands. We use optical emission-line ratios from the literature to re-classify 24 galaxies as star-forming, accreting onto a supermassive black hole (AGNs), transition objects, or low-ionization nuclear emission regions (LINERs). Two-thirds of our galaxies have nuclear X-ray sources with $Swift$/UVOT counterparts. Two nuclei have $L_{X,{\rm 0.5-8.0 keV}}$~$ > 10^{42}$ erg s$^{-1}$, are strong multi-wavelength AGNs and follow the known $α_{\rm OX}-νL_{ν,\rm near UV}$ correlation for strong AGNs. Otherwise, most nuclei are X-ray faint, consistent with either a low-luminosity AGN or a nuclear X-ray binary population, and fall in the "non-AGN locus" in $α_{\rm OX}-νL_{ν,\rm near UV}$ space, which also hosts other, normal, galaxies. Our results suggest that HCG X-ray nuclei in high specific star formation rate spiral galaxies are likely dominated by star formation, while those with low specific star formation rates in earlier types likely harbor a weak AGN. The AGN fraction in HCG galaxies with $M_R \le -20$ and $L_{X,{\rm 0.5-8.0 keV}} \ge 10^{41}$ erg s$^{-1}$ is $0.08^{+0.35}_{-0.01}$, somewhat higher than the $\sim 5%$ fraction in galaxy clusters.
description: 77 pages (emulateapj), 28 tables, 11 figures. Accepted by ApJS on March 5, 2014
The impact of spin-kick alignment on the inferred velocity distribution of isolated pulsars
Creators: name: Mandel, Ilya
name: Igoshev, Andrei P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The speeds of young isolated pulsars are generally inferred from their observed 2-d velocities on the plane of the sky under the assumption that the unobserved radial velocity is not special, i.e., that the measured 2-d velocity is an isotropic projection of the full 3-d velocity. However, if pulsar spins are preferentially aligned with kicks, then the observer's viewing angle relative to the pulsar velocity vector is in fact special because the direction of the spin impacts the detectability of the pulsar. This means that the measured 2-d velocity of observable pulsars is not an isotropic projection, which affects inference on 3-d velocities. We estimate this effect and conclude that it could lead to a ~15% systematic over-estimate of neutron star natal kicks if young pulsars have high obliquity angles and narrow beams, but the exact correction factor depends on the distribution of beam-spin and spin-kick misalignment angles and beam widths.
description: Updated to published version
Compositional Belief Update
Creators: name: Delgrande, James
name: Jin, Yi
name: Pelletier, Francis Jeffry
Publisher: name: arXiv
Year: 2014
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: In this paper we explore a class of belief update operators, in which the definition of the operator is compositional with respect to the sentence to be added. The goal is to provide an update operator that is intuitive, in that its definition is based on a recursive decomposition of the update sentences structure, and that may be reasonably implemented. In addressing update, we first provide a definition phrased in terms of the models of a knowledge base. While this operator satisfies a core group of the benchmark Katsuno-Mendelzon update postulates, not all of the postulates are satisfied. Other Katsuno-Mendelzon postulates can be obtained by suitably restricting the syntactic form of the sentence for update, as we show. In restricting the syntactic form of the sentence for update, we also obtain a hierarchy of update operators with Winsletts standard semantics as the most basic interesting approach captured. We subsequently give an algorithm which captures this approach; in the general case the algorithm is exponential, but with some not-unreasonable assumptions we obtain an algorithm that is linear in the size of the knowledge base. Hence the resulting approach has much better complexity characteristics than other operators in some situations. We also explore other compositional belief change operators: erasure is developed as a dual operator to update; we show that a forget operator is definable in terms of update; and we give a definition of the compositional revision operator. We obtain that compositional revision, under the most natural definition, yields the Satoh revision operator.
Condensation of Fluctuations in and out of Equilibrium
Creators: name: Zannetti, Marco
name: Corberi, Federico
name: Gonnella, Giuseppe
Publisher: name: arXiv
Year: 2014
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Condensation of fluctuations is an interesting phenomenon conceptually distinct from condensation on average. One stricking feature is that, contrary to what happens on average, condensation of fluctuations may occurr even in the absence of interaction. The explanation emerges from the duality between large deviation events in the given system and typical events in a new and appropriately biased system. This surprising phenomenon is investigated in the context of the Gaussian model, chosen as paradigmatical non interacting system, before and after an istantaneous temperature quench. It is shown that the bias induces a mean-field-like effective interaction responsible of the condensation on average. Phase diagrams, covering both the equilibrium and the off-equilibrium regimes, are derived for observables representative of generic behaviors.
description: 8 pages, 7 figures
Deterministic and stochastic sampling of two coupled Kerr parametric oscillators
Creators: name: Margiani, Gabriel
name: del Pino, Javier
name: Heugel, Toni L.
name: Bousse, Nicholas E.
name: Guerrero, Sebastián
name: Kenny, Thomas W.
name: Zilberberg, Oded
name: Sabonis, Deividas
name: Eichler, Alexander
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The vision of building computational hardware for problem optimization has spurred large efforts in the physics community. In particular, networks of Kerr parametric oscillators (KPOs) are envisioned as simulators for finding the ground states of Ising Hamiltonians. It was shown, however, that KPO networks can feature large numbers of unexpected solutions that are difficult to sample with the existing deterministic (i.e., adiabatic) protocols. In this work, we experimentally realize a system of two classical coupled KPOs, and we find good agreement with the predicted mapping to Ising states. We then introduce a protocol based on stochastic sampling of the system, and we show how the resulting probability distribution can be used to identify the ground state of the corresponding Ising Hamiltonian. This method is akin to a Monte Carlo sampling of multiple out-of-equilibrium stationary states and is less prone to become trapped in local minima than deterministic protocols.
On the Total Perimeter of Homothetic Convex Bodies in a Convex Container
Creators: name: Dumitrescu, Adrian
name: Tóth, Csaba D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Metric Geometry (math.MG)
subject: FOS: Mathematics

description: For two planar convex bodies, $C$ and $D$, consider a packing $S$ of $n$ positive homothets of $C$ contained in $D$. We estimate the total perimeter of the bodies in $S$, denoted ${\rm per}(S)$, in terms of ${\rm per}(D)$ and $n$. When all homothets of $C$ touch the boundary of the container $D$, we show that either ${\rm per}(S)=O(\log n)$ or ${\rm per}(S)=O(1)$, depending on how $C$ and $D$ "fit together," and these bounds are the best possible apart from the constant factors. Specifically, we establish an optimal bound ${\rm per}(S)=O(\log n)$ unless $D$ is a convex polygon and every side of $D$ is parallel to a corresponding segment on the boundary of $C$ (for short, $D$ is \emph{parallel to} $C$). When $D$ is parallel to $C$ but the homothets of $C$ may lie anywhere in $D$, we show that ${\rm per}(S)=O((1+{\rm esc}(S)) \log n/\log \log n)$, where ${\rm esc}(S)$ denotes the total distance of the bodies in $S$ from the boundary of $D$. Apart from the constant factor, this bound is also the best possible.
description: A preliminary version of this paper appeared in Proceedings of the 17th International Workshop on Approximation Algorithms for Combinatorial Optimization Problems (APPROX 2013), Berkeley, CA, 2013, LNCS~8096, pp. 96--109
An ESPResSo implementation of elastic objects immersed in a fluid
Creators: name: Cimrak, Ivan
name: Gusenbauer, Markus
name: Jancigova, Iveta
Publisher: name: arXiv
Year: 2013
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Mathematical Physics (math-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We review the lattice-Boltzmann (LB) method coupled with the immersed boundary (IB) method for the description of combined flow of particulate suspensions with immersed elastic objects. We describe the implementation of the combined LB-IB method into the open-source package ESPResSo. We present easy-to-use structures used to model a closed object in a simulation package, the definition of its elastic properties, and the interaction between the fluid and the immersed object. We also present the test cases with short examples of the code explaining the functionality of the new package.
Modeling of three-dimensional betatron oscillation and radiation reaction in plasma accelerators
Creators: name: Liu, Yulong
name: Zeng, Ming
Publisher: name: arXiv
Year: 2022
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Betatron oscillation is a commonly known phenomenon in laser or beam driven plasma wakefield accelerators. In the conventional model, the plasma wake provides a linear focusing force to a relativistic electron, and the electron oscillates in one transverse direction with the betatron frequency proportional to $1/\sqrtγ$, where $γ$ is the Lorentz factor of the electron. In this work, we extend this model to three-dimensional by considering the oscillation in two transverse and one longitudinal directions. The long-term equations, with motion in the betatron time scale averaged out, are obtained and compared with the original equations by numerical methods. In addition to the longitudinal and transverse damping due to radiation reaction which has been found before, we show phenomena including the longitudinal phase drift, betatron phase shift and betatron polarization change based on our long-term equations. This work can be highly valuable for future plasma based high-energy accelerators and colliders.
description: 9 pages, 4 figures
Homiletyka współczesna o języku kazań i homilii
Creators: name: Sławiński, Henryk
Publisher: name: Zenodo
Year: 2020
Subjects: język religijny, homilia, kazanie, przepowiadanie, homiletyka
religious language, homily, sermon, preaching, homiletics

description: Homiletyka jako dyscyplina teologiczna uprawiana w ramach teologii praktycznej. Termin „homilia” Termin „kazanie” Różnica między „kazaniem” i „homilią” Język homilii i kazań Język mówiony i osobowy; prosty, konkretny i zwięzły; piękny i obrazowy; jasny; dostosowany do pojętności słuchaczy; serdeczny, rodzinny; pozytywny
Secure Control Systems for Autonomous Quadrotors against Cyber-Attacks
Creators: name: Samuel, Belkadi
Publisher: name: Zenodo
Year: 2024

description: The problem of safety for robotic systems has been extensively studied. However, little attention has been given to security issues for three-dimensional systems, such as quadrotors. Malicious adversaries can compromise robot sensors and communication networks, causing incidents, achieving illegal objectives, or even injuring people. This study first designs an intelligent control system for autonomous quadrotors. Then, it investigates the problems of optimal false data injection attack scheduling and countermeasure design for unmanned aerial vehicles. Using a state-of-the-art deep learning-based approach, an optimal false data injection attack scheme is proposed to deteriorate a quadrotor's tracking performance with limited attack energy. Subsequently, an optimal tracking control strategy is learned to mitigate attacks and recover the quadrotor's tracking performance. We base our work on Agilicious, a state-of-the-art quadrotor recently deployed for autonomous settings. This paper is the first in the United Kingdom to deploy this quadrotor and implement reinforcement learning on its platform. Therefore, to promote easy reproducibility with minimal engineering overhead, we further provide (1) a comprehensive breakdown of this quadrotor, including software stacks and hardware alternatives; (2) a detailed reinforcement-learning framework to train autonomous controllers on Agilicious agents; and (3) a new open-source environment that builds upon PyFlyt for future reinforcement learning research on Agilicious platforms. Both simulated and real-world experiments are conducted to show the effectiveness of the proposed frameworks in section 5.2.
Employees' Perception of the Problems and Practices of Employee Performance Evaluation: A Case Study of Awash International Bank (AIB)
Creators: name: ZELALEM BAYISA
Publisher: name: Zenodo
Year: 2007

description: This project is designed to assess the perception of employees towards the

practices and problems of performance evaluation in Awash International Bank

To this end; the study has the objective to assess the perception of employees

towards the problems and practices of performance evaluation. On the basis of

data collected through questionnaires and interview which are founded on the

theoretical assessment of related literatures; I have tried to unearth some of the

real problems of appraisals based on the opinion of the ratees in that particular

organization
Reviews: Kingdom, civitas and county: The evolution of territorial identity in the English landscape;Sacred Britannia: The gods and rituals of Roman Britain; Wulfhere's people: A conversion period Anglo-Saxon cemetery at Wolverton, Milton Keynes; The toll roads of Buckinghamshire
Creators: name: Wilson, Nigel
name: Kidd, Sandy
name: Ghirelli, Michael
Publisher: name: Archaeology Data Service
Year: 2023

description: Records of Buckinghamshire, 59, 287-293
The Origin of Buckling Instability in Galactic Bars: Searching for the Scapegoat
Creators: name: Li, Xingchen
name: Shlosman, Isaac
name: Pfenniger, Daniel
name: Heller, Clayton
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The buckling process in stellar bars is full of unsolved issues. We analyze the origin of the buckling instability in stellar bars using high-resolution N-body simulations. Previous studies have promoted the nonresonant firehose instability to be responsible for the vertical buckling. We have analyzed the buckling process in terms of the resonant excitation of stellar orbits in the bar, which pumps energy into vertical oscillations. We find that (1) the buckling is associated with an abrupt increase in the central mass concentration and triggers velocities along the bar and along its rotation axis. The velocity field projected on one of the main axes forms circulation cells and increases vorticity, which are absent in firehose instability; (2) The bending amplitude is nonlinear when measured by isodensity contours or curvature of the Laplace plane, which has a substantial effect on the stellar motions; (3) In the linear description, the planar and vertical 2:1 resonances appear only with the buckling and quickly reach the overlapping phase, thus supporting the energy transfer; (4) Using nonlinear orbit analysis, we analyze the stellar oscillations along the bar and along the rotation axis and find that stars cross the vertical 2:1 resonance simultaneously with the buckling. The overlapping planar and vertical 2:1 resonances trapping more than 25% of the bar particles provide the 'smoking gun' pointing to a close relationship between the bending of stellar orbits and the resonant action -- these particles provide the necessary ingredient assuring the cohesive response in the growing vertical asymmetry. We conclude that resonant excitation is important in triggering the buckling instability, and the contribution from the firehose instability should be reevaluated. Finally, we discuss some observational implications of buckling.
description: Submitted to MNRAS, 16 pages, 18 figures Correct a typo in the caption of figure 6
Constructing a family of conformally flat scalar field models
Creators: name: Apostolopoulos, Pantelis S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Using purely geometrical methods we present a mechanism to solve the scalar field equations of motion (non-minimally coupled with gravity) in a spherically symmetric background. We found that the \emph{full }set of spacetimes, which are of Petrov type O (conformally flat) and admit a \emph{gradient} Conformal Vector Field, can be determined completely. It is shown that the full group of scalar field equations reduced to a \emph{single} equation that depends only on the distance $w=r^{2}-t^{2}$ leaving the metric function (equivalently the functional form of the scalar field or the potential) freely chosen. Depending on the structure of the metric or the potential $V$ (as a function of $ϕ$) a solution can be found either analytically or via numerical integration. We provide physically sound examples and prove that (Anti)-de Sitter fits this scheme. We also reconstruct a recently found solution \cite{Strumia:2022kez} representing an expanding scalar bubble with metric that has a singularity and corresponds to what is termed as Anti-de Sitter crunch.
description: 8 pages, no figures, uses iop class style; (v2) minor typos corrected; (v3) small extension in the abstract to indicate the inclusion of the non-minimally coupled scalar field within the article and some new references were added. Matches version to appear in Classical and Quantum Gravity as a Letter
A Rigorously Bayesian Beam Model and an Adaptive Full Scan Model for Range Finders in Dynamic Environments
Creators: name: De Laet, Tinne
name: De Schutter, Joris
name: Bruyninckx, Herman
Publisher: name: arXiv
Year: 2014
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: This paper proposes and experimentally validates a Bayesian network model of a range finder adapted to dynamic environments. All modeling assumptions are rigorously explained, and all model parameters have a physical interpretation. This approach results in a transparent and intuitive model. With respect to the state of the art beam model this paper: (i) proposes a different functional form for the probability of range measurements caused by unmodeled objects, (ii) intuitively explains the discontinuity encountered in te state of the art beam model, and (iii) reduces the number of model parameters, while maintaining the same representational power for experimental data. The proposed beam model is called RBBM, short for Rigorously Bayesian Beam Model. A maximum likelihood and a variational Bayesian estimator (both based on expectation-maximization) are proposed to learn the model parameters. Furthermore, the RBBM is extended to a full scan model in two steps: first, to a full scan model for static environments and next, to a full scan model for general, dynamic environments. The full scan model accounts for the dependency between beams and adapts to the local sample density when using a particle filter. In contrast to Gaussian-based state of the art models, the proposed full scan model uses a sample-based approximation. This sample-based approximation enables handling dynamic environments and capturing multi-modality, which occurs even in simple static environments.
Geodesics dynamics in the Linet-Tian spacetime with Lambda<0
Creators: name: Brito, Irene
name: da Silva, M. F. A.
name: Mena, Filipe C.
name: Santos, N. O.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We investigate the geodesics' kinematics and dynamics in the Linet-Tian metric with Lambda<0 and compare with the results for the Levi-Civita metric, when Lambda=0. This is used to derive new stability results about the geodesics' dynamics in static vacuum cylindrically symmetric spacetimes with respect to the introduction of Lambda<0. In particular, we find that increasing |Lambda| always increases the minimum and maximum radial distances to the axis of any spatially confined planar null geodesic. Furthermore, we show that, in some cases, the inclusion of any Lambda<0 breaks the geodesics' orbit confinement of the Lambda=0 metric, for both planar and non-planar null geodesics, which are therefore unstable. Using the full system of geodesics' equations, we provide numerical examples which illustrate our results.
description: 25 pages, 13 figures
Circular law for random matrices with exchangeable entries
Creators: name: Adamczak, Radosław
name: Chafaï, Djalil
name: Wolff, Paweł
Publisher: name: arXiv
Year: 2014
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: An exchangeable random matrix is a random matrix with distribution invariant under any permutation of the entries. For such random matrices, we show, as the dimension tends to infinity, that the empirical spectral distribution tends to the uniform law on the unit disc. This is an instance of the universality phenomenon known as the circular law, for a model of random matrices with dependent entries, rows, and columns. It is also a non-Hermitian counterpart of a result of Chatterjee on the semi-circular law for random Hermitian matrices with exchangeable entries. The proof relies in particular on a reduction to a simpler model given by a random shuffle of a rigid deterministic matrix, on Hermitization, and also on combinatorial concentration of measure and combinatorial Central Limit Theorem. A crucial step is a polynomial bound on the smallest singular value of exchangeable random matrices, which may be of independent interest.
Probing the hadron mass spectrum in dense two-color QCD with the linear sigma model
Creators: name: Suenaga, Daiki
name: Murakami, Kotaro
name: Itou, Etsuko
name: Iida, Kei
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We investigate modifications of hadron masses at finite quark chemical potential in two-flavor and two-color QCD, of which the data are available from lattice simulations, within a linear sigma model based on approximate Pauli-Gursey $SU(4)$ symmetry. The model describes not only ground-state scalar diquarks and pseudo-scalar mesons but also the excited pseudo-scalar diquarks and scalar mesons; each ground-state diquark (meson) has the corresponding excited diquark (hadron) with opposite parity as a chiral partner. Effects of chiral symmetry breaking and diquark condensates are incorporated by a mean-field treatment. We show that various mixings among the hadrons, which are triggered by the breakdown of baryon number conservation in the superfluid phase, lead to a rich hadron mass spectrum. We discuss the influence of $U(1)_A$ anomaly on the density dependence of the mass spectrum and also manifestations of the chiral partner structures as density increases in the superfluid phase. The predicted hadron masses are expected to provide future lattice simulations with useful information on such symmetry properties in dense two-color QCD.
description: 16 pages, 6 figures
Characterization of the non-classical relation between measurement outcomes represented by non-orthogonal quantum states
Creators: name: Ji, Ming
name: Hofmann, Holger F.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum mechanics describes seemingly paradoxical relations between the outcomes of measurements that cannot be performed jointly. In Hilbert space, the outcomes of such incompatible measurements are represented by non-orthogonal states. In this paper, we investigate how the relation between outcomes represented by non-orthogonal quantum states differs from the relations suggested by a joint assignment of measurement outcomes that do not depend on the actual measurement context. The analysis is based on a well-known scenario where three statements about the impossibilities of certain outcomes would seem to make a specific fourth outcome impossible as well, yet quantum theory allows the observation of that outcome with a non-vanishing probability. We show that the Hilbert space formalism modifies the relation between the four measurement outcomes by defining a lower bound of the fourth probability that increases as the total probability of the first three outcomes drops to zero. Quantum theory thus makes the violation of non-contextual consistency between the measurement outcomes not only possible, but actually requires it as a necessary consequence of the Hilbert space inner products that describe the contextual relation between the outcomes of different measurements.
description: 10 pages, 1 figure, improved introduction and notation
Multilayer graphenes as a platform for interaction-driven physics and topological superconductivity
Creators: name: Ghazaryan, Areg
name: Holder, Tobias
name: Berg, Erez
name: Serbyn, Maksym
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Motivated by the recent discoveries of superconductivity in bilayer and trilayer graphene, we theoretically investigate superconductivity and other interaction-driven phases in multilayer graphene stacks. To this end, we study the density of states of multilayer graphene with up to four layers at the single-particle band structure level in the presence of a transverse electric field. Among the considered structures, tetralayer graphene with rhombohedral (ABCA) stacking reaches the highest density of states. We study the phases that can arise in ABCA graphene by tuning the carrier density and transverse electric field. For a broad region of the tuning parameters, the presence of strong Coulomb repulsion leads to a spontaneous spin and valley symmetry breaking via Stoner transitions. Using a model that incorporates the spontaneous spin and valley polarization, we explore the Kohn-Luttinger mechanism for superconductivity driven by repulsive Coulomb interactions. We find that the strongest superconducting instability is in the $p-$wave channel, and occurs in proximity to the onset of Stoner transitions. Interestingly, we find a range of densities and transverse electric fields where superconductivity develops out of a strongly corrugated, singly-connected Fermi surface in each valley, leading to a topologically non-trivial chiral $p+ip$ superconducting state with an even number of co-propagating chiral Majorana edge modes. Our work establishes ABCA stacked tetralayer graphene as a promising platform for observing strongly correlated physics and topological superconductivity.
description: 7+10 pages; 5+9 figures
Non-equilibrium relaxations: ageing and finite-size effects
Creators: name: Henkel, Malte
Publisher: name: arXiv
Year: 2022
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: The long-time behaviour of spin-spin correlators in the slow relaxation of systems undergoing phase-ordering kinetics is studied in geometries of finite size. A phenomenological finite-size scaling ansatz is formulated and tested through the exact solution of the kinetic spherical model, quenched to below the critical temperature, in $2
description: 1+21 pp, Latex 2e, 3 figures included