cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Lyman-alpha Absorption from Heliosheath Neutrals
Creators: name: Wood, Brian E.
name: Izmodenov, Vladislav V.
name: Linsky, Jeffrey L.
name: Malama, Yury G.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We assess what information HST observations of stellar Ly-alpha lines can provide on the heliosheath, the region of the heliosphere between the termination shock and heliopause. To search for evidence of heliosheath absorption, we conduct a systematic inspection of stellar Ly-alpha lines reconstructed after correcting for ISM absorption (and heliospheric/astrospheric absorption, if present). Most of the stellar lines are well centered on the stellar radial velocity, as expected, but the three lines of sight with the most downwind orientations relative to the ISM flow (Chi1 Ori, HD 28205, and HD 28568) have significantly blueshifted Ly-alpha lines. Since it is in downwind directions where heliosheath absorption should be strongest, the blueshifts are almost certainly caused by previously undetected heliosheath absorption. We make an initial comparison between the heliosheath absorption and the predictions of a pair of heliospheric models. A model with a complex multi-component treatment of plasma within the heliosphere predicts less absorption than a model with a simple single-fluid treatment, which leads to better agreement with the data. Finally, we find that nonplanetary energetic neutral atom (ENA) fluxes measured by the ASPERA-3 instrument on board Mars Express, which have been interpreted as being from the heliosheath, are probably too high to be consistent with the relative lack of heliosheath absorption seen by HST. This would argue for a local interplanetary source for these ENAs instead of a heliosheath source.
description: 27 pages, 7 figures, AASTEX v5.0, accepted by ApJ
Strong anisotropy of electron-phonon interaction in NbP probed by magnetoacoustic quantum oscillations
Creators: name: Schindler, Clemens
name: Gorbunov, Denis
name: Zherlitsyn, Sergei
name: Galeski, Stanislaw
name: Schmidt, Marcus
name: Wosnitza, Jochen
name: Gooth, Johannes
Publisher: name: arXiv
Year: 2020
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this study, we report on the observation of de Haas-van Alphen-type quantum oscillations (QO) in the ultrasound velocity of NbP as well as `giant QO' in the ultrasound attenuation in pulsed magnetic fields. The difference of the QO amplitude for different acoustic modes reveals a strong anisotropy of the effective deformation potential, which we estimate to be as high as $9\,\mathrm{eV}$ for certain parts of the Fermi surface. Furthermore, the natural filtering of QO frequencies and the tracing of the individual Landau levels to the quantum limit allows for a more detailed investigation of the Fermi surface of NbP as was previously achieved by means of analyzing QO observed in magnetization or electrical resistivity.
description: 5 figures
Viscosity driven instability in rotating relativistic stars
Creators: name: Saijo, Motoyuki
name: Gourgoulhon, Eric
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We investigate the viscosity driven instability in rotating relativistic stars by means of an iterative approach. We focus on polytropic rotating equilibrium stars and impose an m=2 perturbationin the lapse. We vary both the stiffness of the equation of state and the compactness of the star to study those effects on the value of the threshold. For a uniformly rotating star, the criterion T/W, where T is the rotational kinetic energy and W is the gravitational binding energy, mainly depends on the compactness of the star and takes values around 0.13 ~ 0.16, which differ slightly from that of Newtonian incompressible stars (~ 0.14). For differentially rotating stars, the critical value of T/W is found to span the range 0.17 - 0.25. This is significantly larger than the uniformly rotating case with the same compactness of the star. Finally we discuss a possibility of detecting gravitational waves from viscosity driven instability with ground-based interferometers.
description: v1: 14 pages with 10 figures, revtex4.cls. Submitted to Physical Review D; v2: Minor correction to the central enthalpy and typos, 13 pages with 10 figures, revtex4.cls. Physical Review D (2006) in press; v3: Published version, 13 pages with 10 figures, revtex4.cls. Physical Review D (2006) 084006
A Hodge - De Rham Dirac operator on the quantum ${\rm SU}(2)$
Creators: name: Di Cosmo, Fabio
name: Marmo, Giuseppe
name: Pérez-Pardo, Juan Manuel
name: Zampini, Alessandro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Algebra (math.QA)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We describe how it is possible to describe irreducible actions of the Hodge - de Rham Dirac operator upon the exterior algebra over the quantum spheres ${\rm SU}_q(2)$ equipped with a three dimensional left covariant calculus.
description: 18 pages
Structures in the Gauge/Gravity Duality Cascade
Creators: name: Hailu, Girma
name: Tye, S. -H. Henry
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study corrections to the anomalous mass dimension and their effects in the Seiberg duality cascade in the Klebanov-Strassler throat, where $\mathcal{N}=1$ supersymmetric $SU(N+M)\times SU(N)$ gauge theory with bifundamental chiral superfields and a quartic tree level superpotential in four dimensions is dual to type IIB string theory on $AdS_5 \times T^{1,1}$ background. Analyzing the renormalization group flow of the couplings on the gauge theory side, we propose specific corrections to the anomalous mass dimension. Applying gauge/gravity duality, we then show that the corrections reveal structures on the supergravity side with steps appearing in the running of the fluxes and the metric. The "charges" at the steps provide a gravitational source for Seiberg duality transformations. The finiteness of these corrections suggests that the theory flows to a baryonic branch rather than to a confining branch. The cosmological implication of the duality cascade and the gauge/gravity duality on the brane inflationary scenario and the cosmic microwave background radiation is pointed out.
description: v3: 40 pages, minor changes and typos fixed
Determination of B*B pi coupling in unquenched QCD
Creators: name: Ohki, Hiroshi
name: Matsufuru, Hideo
name: Onogi, Tetsuya
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The $B^* Bπ$ coupling is a fundamental parameter of chiral effective Lagrangian with heavy-light mesons and can constrain the chiral behavior of $f_B$, $B_B$ and the $B\to πl ν$ form factor in the soft pion limit. We compute the $B^* B π$ coupling with the static heavy quark and the $O(a)$-improved Wilson light quark. Simulations are carried out with $n_f=2$ unquenched $12^3\times 24$ lattices at $β=1.80$ and $16^3\times 32$ lattices at $β=1.95$ generated by CP-PACS collaboration. To improve the statistical accuracy, we employ the all-to-all propagator technique and the static quark action with smeared temporal link variables following the quenched study by Negishi {\it et al.}. These methods successfully work also on unquenched lattices, and determine the $B^*Bπ$ coupling with 1--2% statistical accuracy on each lattice spacing.
description: 19pages,26figures
Statistical process control for improving healthcare processes. A case study in an Italian teaching hospital
Creators: name: Apreda, Mariarosaria
name: Wienand, Ulrich
name: Valpiani, Giorgia
name: Napoli, Nicola
name: Scagliarini, Michele
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2015
Subjects: SECS-S/01 Statistica
SECS-S/05 Statistica sociale

description: This study aims to investigate the utility and potentialities of statistical process control for monitoring performances of healthcare organizations. We retrospectively applied the statistical process control for monitoring perioperative system performance, represented in this study by the operating room turnaround time. The results showed that the control charts are able to identify the steady-state behavior of the process and to detect improvements or deteriorations in process performance over time
Interacting systems of infinite spiking neurons with weights beyond uniform summability
Creators: name: Papageorgiou, Ioannis
Publisher: name: arXiv
Year: 2019
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: We consider an infinite system of spiking neurons with a drift and both excitatory and inhibitory connections. We study conditions for non-explosiveness and the uniqueness of the invariant measure. In particular, we examine conditions that allow this infinite interacting system to go beyond the usual interactions of uniformly summable weights. As a result, we extend the Galves-Löcherbach model beyond the restrictive uniform summability of the model.
An Accelerated Multiboson Algorithm for Coulomb Gases with Dynamical Dielectric Effects
Creators: name: Duncan, A.
name: Sedgewick, R. D.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: A recent reformulation [1] of the problem of Coulomb gases in the presence of a dynamical dielectric medium showed that finite temperature simulations of such systems can be accomplished on the basis of completely local Hamiltonians on a spatial lattice by including additional bosonic fields. For large systems, the Monte Carlo algorithm proposed in Ref. [1] becomes inefficient due to a low acceptance rate for particle moves in a fixed background multiboson field. We show here how this problem can be circumvented by use of a coupled particle-multiboson update procedure that improves acceptance rates on large lattices by orders of magnitude. The method is tested on a one-component plasma with neutral dielectric particles for a variety of system sizes.
description: 13 pages, 2 figures, fixed typos, added references
Simulating the optics of insect eyes using information from microCT
Creators: name: Taylor, Gavin
name: Baird, Emily
name: Beck Martin
name: Bodey, Andrew
Publisher: name: F1000Research
Year: 2015

description: Insects use visual information from their eyes to control many behaviors, ranging from avoiding obstacles to long distance navigation. Yet, insects also inhabit a diverse range of different habitats and are active at different times during the day, placing constraints on the visual cues that are available. The morphology of their eyes provide a direct indication of their visual capabilities, for instance lens dimensions determine how transmitted light will be focused, with photoreceptor placement and dimensions indicating the resolution and sensitivity of the retina. To identify visual adaptions in different species of insects, our research group has performed high-resolution microCT on the eyes of over 30 tropical and temperate insect species at laboratory and synchrotron x-ray sources. We have begun analyzing the data from these scans with the goal of quantifying the visual capabilities of insect’s secondary visual system, the ocelli, which are camera type eyes similar to those of vertebrates.

Our current analysis process involves manually segmenting three regions of the each reconstructed eye, which are the lens, iris and retina. Using these segmented volumes, and an estimation of the lens’s refractive index, we run a voxel based ray-tracing algorithm to calculate the path light from a point source would take through the lens until it strikes the retina. From this we can determine the retinotopic mapping of the visual world, i.e. where light from the world falls on the retina, and also the optical point spread function, which indicates how well the light is focused.

Currently, each retina has been segmented to define its entire volume. However, each retina is composed of several hundred individual photoreceptors. Ideally, we are aiming to automatically segment the location and dimensions of each photoreceptor, which vary in density and size across the retina. Photoreceptor density, along with the calculated optical point spread function, will determine the resolution of the eye, and the photoreceptor dimensions will indicate the optical sensitivity of each ‘pixel’ of the eye. At the anatomical and optical levels, this analysis will completely describe visual capabilities of the insect’s ocelli. This can be compared similar analysis of their primary visual system, the compound eyes. The results of this study will ultimately provide insights into how insect’s two visual systems extract visual information from the habitats they inhabit.
Collective Coordinate Models for 2-Vortex Shape Mode Dynamics
Creators: name: Alonso-Izquierdo, A.
name: Manton, N. S.
name: Guilarte, J. Mateos
name: Wereszczynski, A.
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Models are developed for the motion of charge-2 Abelian Higgs vortices through the 2-vortex moduli space $M$, with the vortices excited by their shape mode oscillations. The models simplify to the well-known geodesic flow on $M$, modified by a potential, when the mode oscillations are fast relative to the moduli space motion and their amplitudes are small. When the lowest-frequency mode is excited with a large amplitude, the geodesic flow is not a correct description. Instead, a chaotic, or even fractal, multi-bounce structure in vortex-vortex collisions is predicted.
description: 24 pages, 6 figures
Elicitação: Relativas
Creators: name: Mỹky, Kamtinuwy
name: Bardagil Mas, Bernat
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2023
Subjects: subject: irn

description: Uma sessão de elicitacão de orações relativas com Kamtinuwy.
An elicitation session of relative clauses with Kamtinuwy.
Speed Profile Definition for GLOSA Implementation on Buses Based on Statistical Analysis of Experimental Data
Creators: name: Vignarca, Daniele
name: Arrigoni, Stefano
name: Sabbioni, Edoardo
name: Cheli, Federico
Publisher: name: arXiv
Year: 2024
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Intelligent Transportation Systems (ITS) are pushing an increasing interest and development when dealing with eco-driving systems. In this framework, this paper presents a method to define speed profiles specifically designed for Green Light Optimal Speed Advisory (GLOSA) systems on buses. GLOSA aims to optimize traffic flow by providing vehicles with real-time speed recommendations synchronized with traffic signal timings. Leveraging statistical analysis of experimental data collected from an urban bus, the study develops a methodology to extract meaningful insights into bus behaviour and traffic dynamics. The proposed approach considers road topology, scheduled bus stops, and signal timings to define simple although suitable speed profiles considering the peculiarities of the motion of a bus in an urban scenario. Through extensive data collection robust statistical data are defined, allowing the definition of vehicle motion profile for effectively develop and implement GLOSA systems. This research contributes to the advancement of Intelligent Transportation Systems by providing realistic data and practical insights for optimizing bus operations in urban environments.
Is There a Fundamental Line for Disk Galaxies?
Creators: name: Simon, Joshua D.
name: Prada, Francisco
name: Vilchez, Jose M.
name: Blitz, Leo
name: Robertson, Brant
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We show that there are strong local correlations between metallicity, surface brightness, and dynamical mass-to-light ratio within M33, analogous to the fundamental line of dwarf galaxies identified by Prada & Burkert (2002). Using near-infrared imaging from 2MASS, the published rotation curve of M33, and literature measurements of the metallicities of HII regions and supergiant stars, we demonstrate that these correlations hold for points at radial distances between 140 pc and 6.2 kpc from the center of the galaxy. At a given metallicity or surface brightness, M33 has a mass-to-light ratio approximately four times as large as the Local Group dwarf galaxies; other than this constant offset, we see broad agreement between the M33 and dwarf galaxy data. We use analytical arguments to show that at least two of the three fundamental line correlations are basic properties of disk galaxies that can be derived from very general assumptions. We investigate the effect of supernova feedback on the fundamental line with numerical models and conclude that while feedback clearly controls the scatter in the fundamental line, it is not needed to create the fundamental line itself, in agreement with our analytical calculations. We also compare the M33 data with measurements of a simulated disk galaxy, finding that the simulation reproduces the trends in the data correctly and matches the fundamental line, although the metallicity of the simulated galaxy is too high, and the surface brightness is lower than that of M33.
description: 14 pages, 14 figures (5 in color). Accepted for publication in ApJ
gem-Dihalocyclopropanes as precursors to alkaloidal ring systems
Creators: name: Lehmann, Anna Louise
Publisher: name: The Australian National University
Year: 2018
Subjects: subject: QD305.H9.L44 2010
subject: Cyclopropane
subject: Organic compounds Synthesis
subject: Ring formation (Chemistry)
subject: Alkaloids Synthesis

description: gem-Dihalocyclopropanes (1) are an important class of compound that play significant roles in contemporary organic synthesis. This is largely due to their ease of preparation, (which is normally accomplished via addition of the relevant dihalocarbene to an alkene), and the wide range of reactions they can undergo. These reactions can be divided into two broad subgroups, those that proceed with retention of the three membered ring, and those where one of the C-C bonds is broken, thus leading to ring cleavage. The vast majority of gem-dihalocyclopropanes described in the literature are the dibromo- or dichloro- systems, as these are the most synthetically accessible (1, where X = Br or Cl). Chapter One of this thesis provides an introduction to the preparation and synthetic utility of gem-dihalocyclopropanes, while the work described in the remainder of this thesis utilises such systems in work directed toward the synthesis of a number of alkaloidal ring-systems. Chapter Two of this thesis outlines work undertaken in the pursuit of a synthesis of pcrhydrohistrionicotoxin (50), a derivative of the alkaloid histrionicotoxin. A silver(l)-promoted cyclopropane ring-opening/spirocyclisation reaction was to be used as the key step in this work. Thus, starting from cyclopentanone, a pair of diastereoisomeric substrates, 124 and 125, has been prepared that contain all the functionality thought necessary for generating a substrate capable of engaging in the key reaction. Chapter Three outlines work undertaken in the pursuit of a synthesis of the core cis-3a-arylhydroindole structure of a number of Amaryllidaceae alkaloids. Starting with gem-dibromoeyclopropane 146, iodide 163 was prepared over' 7 steps, and upon subjection of the latter compound to reductive radical cyclisation conditions resulted in the production of the cis-3a-arylhydroindole 164. Chapter Four outlines the preparation of a senes of N-protected and propargylated l-amino-2-aryl-2-cyclohexenes (213), from gem-dibromocyclopropanes such as 212. Several of these have been showu to undergo an intramolecular Alder-ene (IMAE) reaction in the presence of palladium acetate and the ligand BBEDA to afford C3aarylhexahydroindoles of the general form 214. Certain of these products may serve as precursors to the alkaloid tazettine (133). Chapter Five contains the experimental procedures and data to support all work outlined in this thesis.
Direct CP violation in beauty and charm hadron decays
Creators: name: Bediaga, Ignacio
name: Göbel, Carla
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Since the discovery of CP violation more than 5 decades ago, this phenomenon is still attracting a lot of interest. Among the many fascinating aspects of this subject, this review is dedicated to direct CP violation in non-leptonic decays. The advances within the last decade have been enormous, driven by the increasingly large samples of b- and c-hadron decays, and have led to very interesting results such as large CP asymmetries in charmless B decays and the observation of direct CP violation in the charm sector. We address the quest for understanding the origin of strong phases, the importance of final state interactions and the relation with CPT symmetry, and different approaches to measure direct CP violation in these decays. The main experimental results and their implications are then discussed.
description: 59 pages, 41 figures
On $\mathbb{Z}$-invariant self-adjoint extensions of the Laplacian on quantum circuits
Creators: name: Balmaseda, A.
name: Di Cosmo, F.
name: Pérez-Pardo, J. M.
Publisher: name: arXiv
Year: 2019
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: An analysis of the invariance properties of self-adjoint extensions of symmetric operators under the action of a group of symmetries is presented. For a given group $G$, criteria for the existence of $G$-invariant self-adjoint extensions of the Laplace-Beltrami operator over a Riemannian manifold are illustrated and critically revisited. These criteria are employed for characterising self-adjoint extensions of the Laplace-Beltrami operator on an infinite set of intervals, $Ω$, constituting a quantum circuit, which are invariant under a given action of the group $\mathbb{Z}$. A study of the different unitary representations of the group $\mathbb{Z}$ on the space of square integrable functions on $Ω$ is performed and the corresponding $\mathbb{Z}$-invariant self-adjoint extensions of the Laplace-Beltrami operator are introduced. The study and characterisation of the invariance properties allows for the determination of the spectrum and generalised eigenfunctions in particular examples.
Black Holes and Nuclear Dynamics
Creators: name: Merritt, David
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Supermassive black holes inhabit galactic nuclei, and their presence influences in crucial ways the evolution of the stellar distribution. The low-density cores observed in bright galaxies are probably a result of black hole infall, while steep density cusps like those at the Galactic center are a result of energy exchange between stars moving in the gravitational field of the single black hole. Loss-cone dynamics are substantially more complex in galactic nuclei than in collisionally-relaxed systems like globular clusters due to the wider variety of possible geometries and orbital populations. The rate of star-black hole interactions has begun to be constrained through observations of energetic events associated with stellar tidal disruptions.
description: 9 pages. Invited contribution to "AGN and Galaxy Evolution," held in the Specola Vaticana, Castel Gandolfo, Italy, 3 - 6 October 2005
Josephson junctions, superconducting circuits, and qubit for quantum technologies
Creators: name: Citro, Roberta
name: Guarcello, Claudio
name: Pagano, Sergio
Publisher: name: arXiv
Year: 2024
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In the realm of physics, a pivotal moment occurred six decades ago when Brian Josephson made a groundbreaking prediction, setting in motion a series of events that would eventually earn him the prestigious Nobel Prize eleven years later. This prediction centered around what is now known as the Josephson effect, a phenomenon with far-reaching implications. At the heart of this effect lies the Josephson junction (JJ), a device that has become a linchpin in various scientific applications. This chapter delves into the foundational principles of the Josephson effect and the remarkable properties of JJs. From their role in metrology to their application in radiation detectors, these junctions have ushered in a new era of electronics. Exploiting the unique features of superconductive devices, such as high speed, low dissipation, and dispersion, JJs find today practical implementation in the development of superconductive qubits and nanotechnology applications.
description: This is a preprint of a chapter to be published in New Trends and Platforms for Quantum Technologies edited by Ramon Aguado, Roberta Citro, Maciej Lewenstein and Michael Stern, 2024, Springer reproduced with permission of Springer Nature Switzerland AG. The final authenticated version is available online at: http://dx.doi.org/10.1007/978-3-031-55657-9
Producing the BEANs needed for person-centred healthcare decision making requires translating the wisdom of the clinical crowd
Creators: name: Kaltoft, Mette Kjer
name: Eiring, Øystein
name: Nielsen, Jesper Bo
name: Salkeld, Glenn
name: Dowie, Jack
Publisher: name: F1000Research
Year: 2015

description: Person-Centred Care requires the Best Estimates Available Now (BEANs) for the performance of all relevant options on Person-Important Criteria at the Point of Decision. Three types of criteria are defined in terms of the best source of the BEANs and illustrated using a simplified example of the Bipolar Disorder treatment decision. Expertise-based Network Meta-Analysis via online elicitation is proposed as a compliment to Evidence-based performance ratings, Experts, being familiar with trial results, are asked for their results from head-to-head ‘thought trials’ of all options they are willing to claim ‘reasonable’ amount of clinical experience. Each expert is then treated as a trial in a standard NMA
Blur adaptation, blur sensitivity and visual load
Creators: name: Petrova, Anete
name: Strautina, Laura
name: Peteris Cikmacs
name: Krumina, Gunta
Publisher: name: F1000Research
Year: 2015

description: Blur is an important dimension of the image quality. It is important to increase the knowledge about the perception of blur because of its relevance to visual acuity, control of accommodation and other visual functions. The aim of our study was to find out how the blur adaptation influences the blur sensitivity and to evaluate the effect of visual load on the blur sensitivity because of its connection to accommodative functions. We evaluated different blur perception thresholds (just noticeable blur, target recognition, clear image perception) as blur level was gradually changed before and after additional adaptation to optical defocus. Gaussian blur filter was used to simulate different blur levels. We compared the blur sensitivity before and after at least 5 hour long visual load at near distance (reading) to evaluate the effect of visual load to blur sensitivity in our study. The results showed that adaptation to optical blur (1.0 D simulated myopia) increased blur sensitivity. Thus it decreased blur thresholds by 10 – 48 % according to specific threshold and refractive group. We did not observed statistically significant change in the blur sensitivity after near distance visual load.
Ultra Fast Nonlinear Optical Tuning of Photonic Crystal Cavities
Creators: name: Fushman, Ilya
name: Waks, Edo
name: Englund, Dirk
name: Stoltz, Nick
name: Petroff, Pierre
name: Vuckovic, Jelena
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We demonstrate fast (up to 20 GHz), low power (5 $μW$) modulation of photonic crystal (PC) cavities in GaAs containing InAs quantum dots. Rapid modulation through blue-shifting of the cavity resonance is achieved via free carrier injection by an above-band picosecond laser pulse. Slow tuning by several linewidths due to laser-induced heating is also demonstrated.
The semi-leptonic form factors of $Λ_{b}\toΛ_{c}$ and $Ξ_{b}\toΞ_{c}$ in QCD sum rules
Creators: name: Zhao, Zhen-Xing
name: Li, Run-Hui
name: Shen, Yue-Long
name: Shi, Yu-Ji
name: Yang, Yan-Sheng
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this work, the full leading order results of the form factors for $Ξ_{b}\toΞ_{c}$ and $Λ_{b}\toΛ_{c}$ are obtained in QCD sum rules. Contributions from up to dim-5 have been considered. For completeness, we also study the two-point correlation function to obtain the pole residues of $Ξ_{Q}$ and $Λ_{Q}$, and higher accuracy is achieved. For the three-point correlation function, since stable Borel regions can not be found, about $20\%$ uncertainties are introduced for the form factors of $Ξ_{b}\toΞ_{c}$ and $Λ_{b}\toΛ_{c}$. Our results for the form factors are consistent with those of the Lattice QCD within errors.
description: 17 pages, 5 figures
Target Networks and Over-parameterization Stabilize Off-policy Bootstrapping with Function Approximation
Creators: name: Che, Fengdi
name: Xiao, Chenjun
name: Mei, Jincheng
name: Dai, Bo
name: Gummadi, Ramki
name: Ramirez, Oscar A
name: Harris, Christopher K
name: Mahmood, A. Rupam
name: Schuurmans, Dale
Publisher: name: arXiv
Year: 2024
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: We prove that the combination of a target network and over-parameterized linear function approximation establishes a weaker convergence condition for bootstrapped value estimation in certain cases, even with off-policy data. Our condition is naturally satisfied for expected updates over the entire state-action space or learning with a batch of complete trajectories from episodic Markov decision processes. Notably, using only a target network or an over-parameterized model does not provide such a convergence guarantee. Additionally, we extend our results to learning with truncated trajectories, showing that convergence is achievable for all tasks with minor modifications, akin to value truncation for the final states in trajectories. Our primary result focuses on temporal difference estimation for prediction, providing high-probability value estimation error bounds and empirical analysis on Baird's counterexample and a Four-room task. Furthermore, we explore the control setting, demonstrating that similar convergence conditions apply to Q-learning.
Site-specific Interrogation of an Ionic Chiral Fragment During Photolysis Using an X-ray Free-Electron Laser
Creators: name: Ilchen, Markus
name: Schmidt, Philipp
name: Novikovskiy, Nikolay M.
name: Hartmann, Gregor
name: Rupprecht, Patrick
name: Coffee, Ryan N.
name: Ehresmann, Arno
name: Galler, Andreas
name: Hartmann, Nick
name: Helml, Wolfram
name: Huang, Zhirong
name: Inhester, Ludger
name: Lutman, Alberto A.
name: MacArthur, James P.
name: Maxwell, Timothy
name: Meyer, Michael
name: Music, Valerija
name: Nuhn, Heinz-Dieter
name: Osipov, Timur
name: Ray, Dipanwita
name: Wolf, Thomas J. A.
name: Bari, Sadia
name: Walter, Peter
name: Li, Zheng
name: Moeller, Stefan
name: Knie, André
name: Demekhin, Philipp V.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Short-wavelength free-electron lasers with their ultrashort pulses at high intensities have originated new approaches for tracking molecular dynamics from the vista of specific sites. X-ray pump X-ray probe schemes even allow to address individual atomic constituents with a 'trigger'-event that preludes the subsequent molecular dynamics while being able to selectively probe the evolving structure with a time-delayed second X-ray pulse. Here, we use a linearly polarized X-ray photon to trigger the photolysis of a prototypical chiral molecule, namely trifluoromethyloxirane (C$_3$H$_3$F$_3$O), at the fluorine K-edge at around 700 eV. The evolving fluorine-containing fragments are then probed by a second, circularly polarized X-ray pulse of higher photon energy in order to investigate the chemically shifted inner-shell electrons of the ionic motherfragment for their stereochemical sensitivity. We experimentally demonstrate and theoretically support how two-color X-ray pump X-ray probe experiments with polarization control enable XFELs as tools for chiral recognition.
description: 14 pages, 5 figures
From sound to symbol : a critical analysis of contemporary Australian music theory pedagogy
Creators: name: Van Wezel, Marretje Ida
Publisher: name: The Australian National University
Year: 2018

description: For at least 450 years Western culture has produced music that has been described as 'tonal'. With this music came strict rules that have been taught to multiple generations of student musicians. In contemporary Australia, these guidelines seem to present considerable challenges for many pre-tertiary music students and their teachers. There is a growing body of evidence to show that students are creating harmony 'mathematically', without mentally 'hearing' what is written. Evidence for this consists of examination results and reports written by the Australian Music Examinations Board (AMEB) federal examiners, as well as the results of students' university entrance examinations. Music Craft was published by the AMEB to give teachers support in the teaching of music literacy, tonal harmony, and aural skills. This dissertation argues that music teachers need more support in the teaching of tonal harmony and related aural skills. Music Craft is analysed here to determine whether the support provided in this new course is sufficient and asks whether the workbooks and compact discs are a thorough and incremental method of teaching and learning. Chapter One sets out historical and educational contexts, providing a critical survey of: philosophies of teaching and learning by important theorists and pedagogues from c.1000 to 1952; texts by Australian writers on the teaching of harmony; old and new chord symbols; aural skills; and the importance of the private music studio. Chapter Two offers an analysis of Music Craft and examines the results of a Questionnaire sent to 60 private music teachers in the Australian Capital Territory. It makes observations on the relationship between written and aural exercises and the incremental introduction of harmony in Music Craft. The Questionnaire contains 23 questions and asks what further support teachers need in the teaching of theory and aural skills. Chapter Three discusses the results of this research and makes recommendations for future action.
GaBoDS: The Garching-Bonn Deep Survey: VI. Cosmic shear analysis
Creators: name: Hetterscheidt, M.
name: Simon, P.
name: Schirmer, M.
name: Hildebrandt, H.
name: Schrabback, T.
name: Erben, T.
name: Schneider, P.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Aims. We present a cosmic shear analysis and data validation of 15 square degree high-quality R-band data of the Garching-Bonn Deep Survey obtained with the Wide Field Imager of the MPG/ESO 2.2m telescope. Methods. We measure the two-point shear correlation functions to calculate the aperture mass dispersion. Both statistics are used to perform the data quality control. Combining the cosmic shear signal with a photometric redshift distribution of a galaxy sub-sample obtained from two square degree of UBVRI-band observations of the Deep Public Survey we determine constraints for the matter density Omega_m, the mass power spectrum normalisation sigma_8 and the dark energy density Omega_Lambda in the magnitude interval R in [21.5,24.5]. In this magnitude interval the effective number density of source galaxies is n=12.5/sq. arcmin, and their mean redshift is z_m=0.78. To estimate the posterior likelihood we employ the Monte Carlo Markov Chain method. Results. Using the aperture mass dispersion we obtain for the mass power spectrum normalisation sigma_8=0.80 +- 0.10 (1 sigma statistical error) at a fixed matter density Omega_m=0.30 assuming a flat universe with negligible baryon content and marginalising over the Hubble parameter and the uncertainties in the fitted redshift distribution.
description: 23 pages, 19 figures, submitted to A&A
Computer simulations of cobble structure on a gravel stream bed
Creators: name: Tribe, Selina
Publisher: name: University of British Columbia
Year: 2009

description: In Harris Creek, a gravel bed river in southcentral British Columbia, the large stones protruding from the surface armour of the bed are arranged as curvilinear ridges oriented at varying angles to the flow, defining a net-like surface structure. A computer simulation, using various rules governing the entrainment and deposition of stones, was written to reproduce these structures. The working hypothesis for the simulation is that the patterns are the result of the mutual interaction of stones as they are mobilized into the flow and collide with downstream obstacles. An opposing hypothesis would be that the pattern being imposed on the stones by the flow. A statistical algorithm was developed to identify cobble ridges and their orientations and to allow a comparison between the simulation results and the real example. Simulations using different sized stones in a bed with 10% of its area covered by stones produce flow-parallel, linear clusters resembling cluster bedforms. Simulations using a more densely populated bed, up to 25% covered area, produce a variety of gravel bedforms including cluster bedforms, transverse ribs, some trending at oblique orientations, and arcuate ridges. These results indicate that the magnitude of the stone population influences the suite of bedforms that emerge. Cluster bedforms may be the result of obstacles to the downstream movement of stones in a sparsely populated bed. Furthermore, cluster bedforms may be nuclei from which oblique ridges develop out of excess sediment. Finally, simulations in which large stones are rarely entrained and travel shorter distances than small stones, produce structures very similar to those found in Harris Creek.
Nonlinear magneto-optical rotation with frequency-modulated light in the geophysical field range
Creators: name: Acosta, V.
name: Ledbetter, M. P.
name: Rochester, S. M.
name: Budker, D.
name: Jackson-Kimball, D. F.
name: Hovde, D. C.
name: Gawlik, W.
name: Pustelny, S.
name: Zachorowski, J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Recent work investigating resonant nonlinear magneto-optical rotation (NMOR) related to long-lived ($τ\ts{rel} \sim 1 {\rm s}$) ground-state atomic coherences has demonstrated potential magnetometric sensitivities exceeding $10^{-11} {\rm G/\sqrt{Hz}}$ for small ($\lesssim 1 {\rm μG}$) magnetic fields. In the present work, NMOR using frequency-modulated light (FM NMOR) is studied in the regime where the longitudinal magnetic field is in the geophysical range ($\sim 500 {\rm mG}$), of particular interest for many applications. In this regime a splitting of the FM NMOR resonance due to the nonlinear Zeeman effect is observed. At sufficiently high light intensities, there is also a splitting of the FM NMOR resonances due to ac Stark shifts induced by the optical field, as well as evidence of alignment-to-orientation conversion type processes. The consequences of these effects for FM-NMOR-based atomic magnetometry in the geophysical field range are considered.
description: 8 pages, 8 figures
Stable automorphic forms for the general linear group
Creators: name: Yang, Jae-Hyun
Publisher: name: arXiv
Year: 2019
Subjects: subject: Number Theory (math.NT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 11Fxx, 14Gxx

description: In this paper, we introduce the notion of the stability of automorphic forms for the general linear group and relate the stability of automorphic forms to the moduli space of real tori and the Jacobian real locus.
description: 26 pages. arXiv admin note: text overlap with arXiv:0912.5084, arXiv:1706.07177
Black Flowers and Real Forms of Higher Spin Symmetries
Creators: name: Sammani, R.
name: Saidi, E. H
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Using Chern-Simons formulation, we investigate higher spin (HS) black holes in AdS$_{3}$ with soft Heisenberg hair and establish linkage with the real forms of the underlying complexified gauge symmetries taken here as $SL(N,C)_{L}\times SL(N,C)_{R}.$ We study the various conserved currents characterizing the HS black flowers (HS-BF) and show that they can be formed of layers indexed by the elements of the centre of the gauge symmetry. This feature follows from requiring the holonomy of the asymptotic gauge connection around the thermal cycle to sit in the centre $\mathbb{Z}_{N}$ of the symmetry group. With regard to the compact subgroups of the real forms of the complexified gauge symmetry, we calculate the entropies of the HS-BF and verify that, unless we are considering trivial holonomies, there are no continuous paths joining the HS-BF to the core spin 2 black holes. As explicit illustrations, we give quantum field realisations of the soft Heisenberg hair in terms of bosonic and fermionic primary conformal fields and compute the HS-BF entropy as a function of the number of fermions occupying the ground state of the Heisenberg soft hair.
Short-range order in GeSn alloy
Creators: name: Cao, Boxiao
name: Chen, Shunda
name: Jin, Xiaochen
name: Liu, Jifeng
name: Li, Tianshu
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Group IV alloys have been long viewed as homogeneous random solid solutions since they were first perceived as Si-compatible, direct-band-gap semiconductors 30 years ago. Such a perception underlies the understanding, interpretation and prediction of alloys' properties. However, as the race to create scalable and tunable device materials enters a composition domain far beyond alloys' equilibrium solubility, a fundamental question emerges as to how random these alloys truly are. Here we show, by combining statistical sampling and large-scale ab initio calculations, that GeSn alloy, a promising group IV alloy for mid-infrared technology, exhibits a clear, short-range order for solute atoms within its entire composition range. Such short-range order is further found to substantially affect the electronic properties of GeSn. We demonstrate the proper inclusion of this short-range order through canonical sampling can lead to a significant improvement over previous predictions on alloy's band gaps, by showing an excellent agreement with experiments within the entire studied composition range. Our finding thus not only calls for an important revision of current structural model for group IV alloy, but also suggests short-range order may generically exist in different types of alloys.
description: 26 pages, 6 figures
A systematic investigation of colour and concept associations
Creators: name: Tham, Diana Su Yun
name: Sowden, Paul
name: Grandison, Alexandra
name: Franklin, Anna
name: Lee, Anna
name: Ng, Michelle
Publisher: name: F1000Research
Year: 2015

description: There has been considerable interest in understanding the capacity of colour to shape our functioning and behaviour (Elliot & Maier, 2014). For example, performance on intelligence tests is found to be poorer after exposure to the colour red, compared to green (Elliot et al., 2007). One possibility is that such effects arise through colour-concept associations (i.e., red – failure). Furthermore, the symbolism of a colour may vary across cultures. However, this has not been systematically investigated. The present investigation explores the range of abstract colour associations that English and Chinese speaking adults have, using hues from the World Colour Survey (WCS: Berlin & Kay, 1969, 1991). In a series of two experiments, we explored: the associations that people have with each of the 11 Basic Colour Terms (black, white, red, yellow, green, blue, brown, purple, pink, orange, grey; Experiment 1); and which specific physical colours are associated with the concepts generated in Experiment 1 (Experiment 2). The findings have implications for better understanding effects of colour on behaviour and enable us to make and systematically test predictions about the direction of colour-behaviour effects across colour space.

Supported by a European Research Council funded project (‘CATEGORIES’, 283605) to AF
High dimensional density estimation with sparse grids
Creators: name: Wilson, Padarn George
Publisher: name: The Australian National University
Year: 2018

description: Density estimation is a classical and well studied problem in modern statistics. In the case of low dimensional problems there are a wide array of well understood and efficient non-parametric methods in the existing literature. In contrast, high dimensional density estimation remains a very challenging problem in this field. As the dimension of the variable space increases there is an exponential growth in both the computational complexity of the problem and in the required sample size. This is a fundamental difficulty, and no single technique can avoid it altogether. Instead, techniques must be developed that take advantage of problem specific information or simplifying assumptions. In this thesis we study a particularly relevant situation in modern statistics, in which there is a large quantity of data and the underlying dimension of the problem is reasonably high. In this situation, the most flexible methods are too computationally expensive, and specification of reasonable parametric models becomes too difficult. We propose a range of techniques which utilize the concept of Sparse Grids. This is a technique that exploits additional regularity assumptions to allow a more efficient grid based representation of a function. This grid like approach allows an efficient treatment of massive data sets, while still possessing a reasonable degree of flexibility. We present different options for estimating density functions using a Sparse Grid. These estimators are examined first through a systematic study of the estimators theoretical properties, then through numerical examples of their real world performance and computational feasibility.