cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Derivation of Instrument Requirements for Polarimetry using Mg, Fe, and Mn lines between 250 and 290 nm
Creators: name: de Wijn, A. G.
name: Judge, P. G.
name: Ezzeddine, R.
name: Dalda, A. Sainz
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Judge et al. (2021) recently argued that a region of the solar spectrum in the near-UV between about 250 and 290 nm is optimal for studying magnetism in the solar chromosphere due to an abundance of Mg II, Fe II, and Fe I lines that sample various heights in the solar atmosphere. In this paper we derive requirements for spectropolarimetric instruments to observe these lines. We derive a relationship between the desired sensitivity to magnetic field and the signal-to-noise of the measurement from the weak-field approximation of the Zeeman effect. We find that many lines will exhibit observable polarization signals for both longitudinal and transverse magnetic field with reasonable amplitudes.
Investigating the Appification of Classroom Behaviour Management
Creators: name: MITTIGA, SHARON RAJVANSH
Publisher: name: Monash University
Year: 2023
Subjects: classificationCode: 520102
subject: Educational psychology

description: This thesis examines research conducted to date on classroom behaviour management mobile applications (CBM apps). The research was conducted in three parts. First, the effectiveness of CBM apps on promoting positive student behaviour was examined in a systematic literature review. Second, the behaviour change potential of CBM apps was examined in a content analysis using the App Behaviour Change Scale to identify the behaviour change techniques crafted into the design of CBM apps and the user version of the Mobile App Rating Scale to evaluate the quality of CBM apps. Lastly, Australian teachers' readiness to adopt CBM apps in their classrooms was explored via a Qualtrics survey.
Inclined Pulsar Magnetospheres in General Relativity: Polar Caps for the Dipole, Quadrudipole and Beyond
Creators: name: Gralla, Samuel E.
name: Lupsasca, Alexandru
name: Philippov, Alexander
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In the canonical model of a pulsar, rotational energy is transmitted through the surrounding plasma via two electrical circuits, each connecting to the star over a small region known as a "polar cap." For a dipole-magnetized star, the polar caps coincide with the magnetic poles (hence the name), but in general, they can occur at any place and take any shape. In light of their crucial importance to most models of pulsar emission (from radio to X-ray to wind), we develop a general technique for determining polar cap properties. We consider a perfectly conducting star surrounded by a force-free magnetosphere and include the effects of general relativity. Using a combined numerical-analytical technique that leverages the rotation rate as a small parameter, we derive a general analytic formula for the polar cap shape and charge-current distribution as a function of the stellar mass, radius, rotation rate, moment of inertia, and magnetic field. We present results for dipole and quadrudipole fields (superposed dipole and quadrupole) inclined relative to the axis of rotation. The inclined dipole polar cap results are the first to include general relativity, and they confirm its essential role in the pulsar problem. The quadrudipole pulsar illustrates the phenomenon of thin annular polar caps. More generally, our method lays a foundation for detailed modeling of pulsar emission with realistic magnetic fields.
description: 12 pages, 4 figures. v2: minor edits, matches published version. Related videos available at https://youtu.be/M_ruTbM8YNo
Core-clad Pr(3+)-doped Ga(In)-Ge-As-Se-(I) glass fibers: preparation, investigation, simulation of laser characteristics
Creators: name: Karaksina, E. V.
name: Shiryaev, V. S.
name: Churbanov, M. F.
name: Anashkina, E. A.
name: Kotereva, T. V.
name: Snopatin, G. E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Core-clad fibers on the basis of high-purity 1300 ppmw Pr(3+)-doped Ga-Ge-As-Se and 2000 ppmw Pr(3+) -doped In-Ge-As-Se-I glasses have been prepared. The minimum optical losses of the fibers are at the level of 1 dB/m in the wavelength range, where there is no influence of the praseodymium absorption. At present, it is the best result obtained for core-clad rare- earth-doped chalcogenide fibers with high dopant concentration. The fibers exhibit the broadband luminescence in the spectral range of 3.5-5.5 micron. The values of luminescence lifetime at the wavelength of 4.7 micron are within 6.5-8.2 ms closed to those for the bulk glasses obtained previously. Simulation of laser properties for these core-clad fibers in the three-level cascade scheme was carried out. The low level of optical losses experimentally achieved in these fibers is one of main criteria for development of mid-IR fiber systems.
description: 7 pages, 6 figures, 2 tables. Published in Optical Materials
Effective action from M-theory on twisted connected sum $G_2$-manifolds
Creators: name: Guio, Thaisa C. da C.
name: Jockers, Hans
name: Klemm, Albrecht
name: Yeh, Hung-Yu
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Algebraic Geometry (math.AG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study the four-dimensional low energy effective $\mathcal{N}=1$ supergravity theory of the dimensional reduction of M-theory on $G_2$-manifolds, which are constructed by Kovalev's twisted connected sum gluing suitable pairs of asymptotically cylindrical Calabi-Yau threefolds $X_{L/R}$ augmented with a circle $S^1$. In the Kovalev limit the Ricci-flat $G_2$-metrics are approximated by the Ricci-flat metrics on $X_{L/R}$ and we identify the universal modulus - the Kovalevton - that parametrizes this limit. We observe that the low energy effective theory exhibits in this limit gauge theory sectors with extended supersymmetry. We determine the universal (semi-classical) Kähler potential of the effective $\mathcal{N}=1$ supergravity action as a function of the Kovalevton and the volume modulus of the $G_2$-manifold. This Kähler potential fulfills the no-scale inequality such that no anti-de-Sitter vacua are admitted. We describe geometric degenerations in $X_{L/R}$, which lead to non-Abelian gauge symmetries enhancements with various matter content. Studying the resulting gauge theory branches, we argue that they lead to transitions compatible with the gluing construction and provide many new explicit examples of $G_2$-manifolds.
description: 79 pages, v2: refs. added, typos corrected, Appendix A expanded, v3: minor corrections, typos corrected, discussion of dimensional reduction improved, version published in CMP
Random Matrices and Holographic Tensor Models
Creators: name: Krishnan, Chethan
name: Kumar, K. V. Pavan
name: Sanyal, Sambuddha
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We further explore the connection between holographic $O(n)$ tensor models and random matrices. First, we consider the simplest non-trivial uncolored tensor model and show that the results for the density of states, level spacing and spectral form factor are qualitatively identical to the colored case studied in arXiv:1612.06330. We also explain an overall 16-fold degeneracy by identifying various symmetries, some of which were unavailable in SYK and the colored models. Secondly, and perhaps more interestingly, we systematically identify the Spectral Mirror Symmetry and the Time-Reversal Symmetry of both the colored and uncolored models for all values of $n$, and use them to identify the Andreev ensembles that control their random matrix behavior. We find that the ensembles that arise exhibit a refined version of Bott periodicity in $n$.
description: 27 pages, 7 figures; v2: references added, minor improvements; v3: minor improvements, added an appendix reviewing the symmetry classification. Journal version
Flexible and Robust Counterfactual Explanations with Minimal Satisfiable Perturbations
Creators: name: Wang, Yongjie
name: Qian, Hangwei
name: Liu, Yongjie
name: Guo, Wei
name: Miao, Chunyan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Counterfactual explanations (CFEs) exemplify how to minimally modify a feature vector to achieve a different prediction for an instance. CFEs can enhance informational fairness and trustworthiness, and provide suggestions for users who receive adverse predictions. However, recent research has shown that multiple CFEs can be offered for the same instance or instances with slight differences. Multiple CFEs provide flexible choices and cover diverse desiderata for user selection. However, individual fairness and model reliability will be damaged if unstable CFEs with different costs are returned. Existing methods fail to exploit flexibility and address the concerns of non-robustness simultaneously. To address these issues, we propose a conceptually simple yet effective solution named Counterfactual Explanations with Minimal Satisfiable Perturbations (CEMSP). Specifically, CEMSP constrains changing values of abnormal features with the help of their semantically meaningful normal ranges. For efficiency, we model the problem as a Boolean satisfiability problem to modify as few features as possible. Additionally, CEMSP is a general framework and can easily accommodate more practical requirements, e.g., casualty and actionability. Compared to existing methods, we conduct comprehensive experiments on both synthetic and real-world datasets to demonstrate that our method provides more robust explanations while preserving flexibility.
description: Accepted by CIKM 2023
title: Linking atmospheric and marine redox evolution during the Great Oxidation Event — Isotopic insights from the Duitschland and Rooihoogte formations (South Africa)
Creators: name: Havsteen, Julius
name: Kleinhanns, Ilka
name: Eickmann, Benjamin
name: Rosca, Carolina
name: Gogouvitis, Markus
name: Beukes, Nic
name: Izon, Gareth
name: Schoenberg, Ronny
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
The correlative Duitschland and Rooihoogte formations (Transvaal Basin) record a critical juncture in Earth’s history since both formations archive a pronounced shift from mass-independent fractionation of sulfur (MIF-S) to mass-dependant fractionation of sulfur, indicative of a slightly oxygenated atmosphere. Surprisingly, however, while multiple sulphur isotope systematics has fundamentally shaped our understanding of atmospheric oxygenation, the evolution experienced within the marine realm has received comparatively little attention. Here we present geochemical transects of four drill-cores intersecting the two formations, affording a three-dimensional, yet somewhat counterintuitive, insight into marine response to atmospheric oxygenation. For instance, rather than signalling more oxygenated conditions, redox-sensitive trace elements disclose persistently suboxic–oxic marine conditions that, in fact, appear to worsen up-section. Interestingly, succeeding the loss of S-MIF, preliminary Mo-isotope data document a c.1‰ shift toward heavier δ98MoNIST+0.25‰ values. This additionally correlates with a negative shift in δ34S to approximately -25‰, a range common for sulfate reducing bacteria, along with an overall increase in both sulfur content and Fe/Mn. This stratigraphic evolution reconciles with a deterioration of local redox conditions by Fe-rich (Mn-poor) sedimentation and/or microbially induced H2S production, which would lower the Mo isotopic offset between δ98Mo in shales and its seawater precursor. The marine redox potential is thus lowered from somewhere between oxic-suboxic to suboxic-anoxic conditions after the loss of MIF-S. Assimilated, at least within the Transvaal Basin, our data expose a geobiological feedback-driven causality between the earliest oxygenation of the atmosphere and a decreased redox potential of the marine realm.

    
Experimental observation of a current-driven instability in a neutral electron-positron beam
Creators: name: Warwick, J.
name: Dzelzainis, T.
name: Dieckmann, M. E.
name: Schumacker, W.
name: Doria, D.
name: Romagnani, L.
name: Poder, K.
name: Cole, J. M.
name: Alejo, A.
name: Yeung, M.
name: Krushelnick, K.
name: Mangles, S. P. D.
name: Najmudin, Z.
name: Reville, B.
name: Samarin, G. M.
name: Symes, D.
name: Thomas, A. G. R.
name: Borghesi, M.
name: Sarri, G.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report on the first experimental observation of a current-driven instability developing in a quasi-neutral matter-antimatter beam. Strong magnetic fields ($\geq$ 1 T) are measured, via means of a proton radiography technique, after the propagation of a neutral electron-positron beam through a background electron-ion plasma.The experimentally determined equipartition parameter of $ε_B \approx 10^{-3}$, is typical of values inferred from models of astrophysical gamma-ray bursts, in which the relativistic flows are also expected to be pair dominated. The data, supported by Particle-In-Cell simulations and simple analytical estimates, indicate that these magnetic fields persist in the background plasma for thousands of inverse plasma frequencies. The existence of such long-lived magnetic fields can be related to analog astrophysical systems, such as those prevalent in lepton-dominated jets.
Interaction-free measurement with mesoscopic devices on a GaAs/AlGaAs heterostructure
Creators: name: Azuma, Hiroo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In this paper, we propose a method for implementing the interaction-free measurement (IFM) with mesoscopic devices fabricated on a high mobility GaAs/AlGaAs heterostructure, where a two-dimensional electron gas (2DEG) system is buried, at low temperature. The IFM is amazing evidence of nonlocality of the quantum mechanics because the IFM offers us the capability to detect the existence of an object without interaction with it. A scheme of Kwiat et al. for realizing the IFM lets a probability that we fail to recognize the presence of the object be as small as we like, using the quantum Zeno effect. Constructing an interferometer of Kwiat et al. for the IFM, we make use of techniques of electron quantum optics and tunnelling microscopes for the 2DEG. We examine a shot noise of an electric current flowing through the interferometer. Our method for performing the IFM aims at achieving a milestone of quantum information processing in mesoscopic systems.
description: v1: 16 pages, 9 eps figures, latex2e; v2: 20 pages, 9 eps figures, a new section about a shot noise of an electric current is added; v3: 17 pages, 6 eps figures, Section 3 is shortened; v4: minor corrections
Updated Global 3+1 Analysis of Short-BaseLine Neutrino Oscillations
Creators: name: Gariazzo, S.
name: Giunti, C.
name: Laveder, M.
name: Li, Y. F.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present the results of an updated fit of short-baseline neutrino oscillation data in the framework of 3+1 active-sterile neutrino mixing. We first consider $ν_e$ and $\barν_e$ disappearance in the light of the Gallium and reactor anomalies. We discuss the implications of the recent measurement of the reactor $\barν_e$ spectrum in the NEOS experiment, which shifts the allowed regions of the parameter space towards smaller values of $|U_{e4}|^2$. The beta-decay constraints allow us to limit the oscillation length between about 2 cm and 7 m at $3σ$ for neutrinos with an energy of 1 MeV. We then consider the global fit of the data in the light of the LSND anomaly, taking into account the constraints from $ν_e$ and $ν_μ$ disappearance experiments, including the recent data of the MINOS and IceCube experiments. The combination of the NEOS constraints on $|U_{e4}|^2$ and the MINOS and IceCube constraints on $|U_{\mu4}|^2$ lead to an unacceptable appearance-disappearance tension which becomes tolerable only in a pragmatic fit which neglects the MiniBooNE low-energy anomaly. The minimization of the global $χ^2$ in the space of the four mixing parameters $Δ{m}^2_{41}$, $|U_{e4}|^2$, $|U_{\mu4}|^2$, and $|U_{\tau4}|^2$ leads to three allowed regions with narrow $Δ{m}^{2}_{41}$ widths at $ Δm^2_{41} \approx 1.7 $ (best-fit), 1.3 (at $2σ$), 2.4 (at $3σ$) eV$^2$. The restrictions of the allowed regions of the mixing parameters with respect to our previous global fits are mainly due to the NEOS constraints. We present a comparison of the allowed regions of the mixing parameters with the sensitivities of ongoing experiments, which show that it is likely that these experiments will determine in a definitive way if the reactor, Gallium and LSND anomalies are due to active-sterile neutrino oscillations or not.
description: 39 pages; improved treatment of the reactor flux uncertainties and other minor corrections
Thermal effects on $ρ$ meson properties in an external magnetic field
Creators: name: Ghosh, Snigdha
name: Mukherjee, Arghya
name: Mandal, Mahatsab
name: Sarkar, Sourav
name: Roy, Pradip
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: A detailed study of the analytic structure of 1-loop self energy graphs for neutral and charged $ρ$ mesons is presented at finite temperature and arbitrary magnetic field using the real time formalism of thermal field theory. The imaginary part of the self energy is obtained from the discontinuities of these graphs across the Unitary and Landau cuts, which is seen to be different for $ρ^0$ and $ρ^\pm$. The magnetic field dependent vacuum contribution to the real part of the self energy, which is usually ignored, is found to be appreciable. A significant effect of temperature and magnetic field is seen in the self energy, spectral function, effective mass and dispersion relation of $ρ^0$ as well as of $ρ^\pm$ relative to its trivial Landau shift. However, for charged $ρ$ mesons, on account of the dominance of the Landau term, the effective mass appears to be independent of temperature. The trivial coupling of magnetic moment of $ρ^\pm$ with external magnetic field, when incorporated in the calculation, makes the $ρ^\pm$ to condense at high magnetic field.
A New Interpretation of Vortex-Split Sudden Stratospheric Warmings in Terms of Equilibrium Statistical Mechanics
Creators: name: Yasuda, Yuki
name: Bouchet, Freddy
name: Venaille, Antoine
Publisher: name: arXiv
Year: 2017
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Vortex-split sudden stratospheric warmings (S-SSWs) are investigated by using the Japanese 55-year Reanalysis (JRA-55), a spherical barotropic quasi-geostrophic (QG) model, and equilibrium statistical mechanics. The QG model reproduces well the evolution of the composite potential vorticity (PV) field obtained from JRA-55 by considering a time-dependent effective topography given by the composite height field of the 550 K potential temperature surface. The zonal-wavenumber-2 component of the effective topography is the most essential feature required to observe the vortex splitting. The statistical-mechanics theory predicts a large-scale steady state as the most probable outcome of turbulent stirring, and such a state can be computed without solving the QG dynamics. The theory is applied to a disk domain, which is modeled on the north polar cap in the stratosphere. The equilibrium state is obtained by computing the maximum of an entropy functional. In the range of parameters relevant to the winter stratosphere, this state is anticyclonic. By contrast, cyclonic states are quasi-stationary states corresponding to saddle points of the entropy functional. The theoretical calculations are compared with the results of the quasi-static experiment in which the wavenumber-2 topographic amplitude is increased linearly and slowly with time. The results suggest that S-SSWs can be qualitatively interpreted as the transition from the cyclonic quasi-stationary state toward the anticyclonic equilibrium state. The polar vortex splits during the transition toward the equilibrium state. Without any forcing such as radiative cooling, the anticyclonic equilibrium state would be realized sufficiently after an S-SSW.
description: 23 pages, 11 figures
Observing a scale anomaly and a universal quantum phase transition in graphene
Creators: name: Ovdat, O.
name: Mao, Jinhai
name: Jiang, Yuhang
name: Andrei, E. Y.
name: Akkermans, E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: One of the most interesting predictions resulting from quantum physics, is the violation of classical symmetries, collectively referred to as anomalies. A remarkable class of anomalies occurs when the continuous scale symmetry of a scale free quantum system is broken into a discrete scale symmetry for a critical value of a control parameter. This is an example of a (zero temperature) quantum phase transition. Such an anomaly takes place for the quantum inverse square potential known to describe 'Efimov physics'. Broken continuous scale symmetry into discrete scale symmetry also appears for a charged and massless Dirac fermion in an attractive $1/r$ Coulomb potential. The purpose of this article is to demonstrate the universality of this quantum phase transition and to present convincing experimental evidence of its existence for a charged and massless fermion in an attractive Coulomb potential as realised in graphene.
description: 7 pages and 6 figures + 7 pages and 5 figures of supplementary material
Galaxies as High-Resolution Telescopes
Creators: name: Barnacka, Anna
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Recent observations show a population of active galaxies with milliarcseconds offsets between optical and radio emission. Such offsets can be an indication of extreme phenomena associated with supermassive black holes including relativistic jets, binary supermassive black holes, or even recoiling supermassive black holes. However, the multi-wavelength structure of active galaxies at a few milliarcseconds cannot be fathomed with direct observations. We propose using strong gravitational lensing to elucidate the multi-wavelength structure of sources. When sources are located close to the caustic of lensing galaxy, even small offset in the position of the sources results in a drastic difference in the position and magnification of mirage images. We show that the angular offset in the position of the sources can be amplified more than 50 times in the observed position of mirage images. We find that at least 8% of the observed gravitationally lensed quasars will be in the caustic configuration. The synergy between SKA and Euclid will provide an ideal set of observations for thousands of gravitationally lensed sources in the caustic configuration, which will allow us to elucidate the multi-wavelength structure for a large ensemble of sources, and study the physical origin of radio emissions, their connection to supermassive black holes, and their cosmic evolution.
description: Accepted for publication in ApJ
A Class of History-Dependent Systems of Evolution Inclusions with Applications
Creators: name: Migorski, S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: This paper is devoted to studying a system of coupled nonlinear first order history-dependent evolution inclusions in the framework of evolution triples of spaces. The multivalued terms are of the Clarke subgradient or of the convex subdifferential form. Using a surjectivity result for multivalued maps and a fixed point argument for a history-dependent operator, we prove that the system has a unique solution. We conclude with two examples of an evolutionary differential variational-hemivariational inequality and of a dynamic frictional contact problem in mechanics, which illustrate the abstract results.
description: 22p
Hilbert space and ground state structure of bilayer quantum Hall systems at $ν=2/λ$
Creators: name: Calixto, M.
name: Peón-Nieto, C.
name: Perez-Romero, E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: 81V70, 81R30

description: We analyze the Hilbert space and ground state structure of bilayer quantum Hall (BLQH) systems at fractional filling factors $ν=2/λ$ ($λ$ odd) and we also study the large $SU(4)$ isospin-$λ$ limit. The model Hamiltonian is an adaptation of the $ν=2$ case [Z.F. Ezawa {\it et al.}, Phys. Rev. {B71} (2005) 125318] to the many-body situation (arbitrary $λ$ flux quanta per electron). The semiclassical regime and quantum phase diagram (in terms of layer distance, Zeeeman, tunneling, etc, control parameters) is obtained by using previously introduced Grassmannian $\mathbb{G}^4_{2}=U(4)/[U(2)\times U(2)]$ coherent states as variational states. The existence of three quantum phases (spin, canted and ppin) is common to any $λ$, but the phase transition points depend on $λ$, and the instance $λ=1$ is recovered as a particular case. We also analyze the quantum case through a numerical diagonalization of the Hamiltonian and compare with the mean-field results, which give a good approximation in the spin and ppin phases but not in the canted phase, where we detect exactly $λ$ energy level crossings between the ground and first excited state for given values of the tunneling gap. An energy band structure at low and high interlayer tunneling (spin and ppin phases, respectively) also appears depending on angular momentum and layer population imbalance quantum numbers.
description: 12 pages, 7 figures. Several paragraphs included at the beginning of Section III, introducing the model Hamiltonian from first principles, and a new section V with some comments about experimental issues
Mutations on a Random Binary Tree with Measured Boundary
Creators: name: Duchamps, Jean-Jil
name: Lambert, Amaury
Publisher: name: arXiv
Year: 2017
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: primary 05C05, 60J80, secondary 54E45, 60G51, 60G55, 60G57, 60K15, 92D10

description: Consider a random real tree whose leaf set, or boundary, is endowed with a finite mass measure. Each element of the tree is further given a type, or allele, inherited from the most recent atom of a random point measure (infinitely-many-allele model) on the skeleton of the tree. The partition of the boundary into distinct alleles is the so-called allelic partition. In this paper, we are interested in the infinite trees generated by supercritical, possibly time-inhomogeneous, binary branching processes, and in their boundary, which is the set of particles `co-existing at infinity'. We prove that any such tree can be mapped to a random, compact ultrametric tree called coalescent point process, endowed with a `uniform' measure on its boundary which is the limit as $t\to\infty$ of the properly rescaled counting measure of the population at time $t$. We prove that the clonal (i.e., carrying the same allele as the root) part of the boundary is a regenerative set that we characterize. We then study the allelic partition of the boundary through the measures of its blocks. We also study the dynamics of the clonal subtree, which is a Markovian increasing tree process as mutations are removed.
description: 45 pages, 6 figures
Asymptotic Formulas for Macdonald Polynomials and the Boundary of the $(q,t)$-Gelfand-Tsetlin Graph
Creators: name: Cuenca, Cesar
Publisher: name: arXiv
Year: 2017
Subjects: subject: Representation Theory (math.RT)
subject: Mathematical Physics (math-ph)
subject: Classical Analysis and ODEs (math.CA)
subject: Combinatorics (math.CO)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 33D52, 33D90 (Primary) 60B15, 60C05 (Secondary)

description: We introduce Macdonald characters and use algebraic properties of Macdonald polynomials to study them. As a result, we produce several formulas for Macdonald characters, which are generalizations of those obtained by Gorin and Panova in [Ann. Probab. 43 (2015), 3052-3132, arXiv:1301.0634], and are expected to provide tools for the study of statistical mechanical models, representation theory and random matrices. As first application of our formulas, we characterize the boundary of the $(q,t)$-deformation of the Gelfand-Tsetlin graph when $t=q^θ$ and $θ$ is a positive integer.
Probing the No-Scale ${\cal F}$-$SU(5)$ One-Parameter Model via Gluino Searches at the LHC2
Creators: name: Li, Tianjun
name: Maxin, James A.
name: Nanopoulos, Dimitri V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In our recent paper entitled "The return of the King: No-Scale ${\cal F}$-$SU(5)$", we showed that the model space supporting the most favorable phenomenology should have been probed in 2016 at the LHC2, with an even further reach into this region of the model in 2017-18. This ideal realm of the one-parameter version of No-Scale ${\cal F}$-$SU(5)$ yields a 1.9-2.3 TeV gluino mass at the very same point where the light Higgs boson mass enters its rather narrow experimentally determined range of $m_h = 125.09 \pm 0.24$ GeV. Given the recent results reported at Moriond 2017 for 36 ${\rm fb}^{-1}$ of luminosity collected in 2016 at the 13 TeV LHC2, we now update the status of the No-Scale ${\cal F}$-$SU(5)$ model space in light of the gluino mass exclusion limits presented by the ATLAS and CMS Collaborations. We illustrate that a resolution could be reached soon as to whether supersymmetry lives in this most critical region of the model space.
description: 4 pages, 2 figures, Physics Letters B version
A New Constraint on Reionization from Evolution of the Ly$α$ Luminosity Function at $z\sim6-7$ Probed by a Deep Census of $z=7.0$ Ly$α$ Emitter Candidates to 0.3 $L^*$
Creators: name: Ota, Kazuaki
name: Iye, Masanori
name: Kashikawa, Nobunari
name: Konno, Akira
name: Nakata, Fumiaki
name: Totani, Tomonori
name: Kobayashi, Masakazu A. R.
name: Fudamoto, Yoshinobu
name: Seko, Akifumi
name: Toshikawa, Jun
name: Ichikawa, Akie
name: Shibuya, Takatoshi
name: Onoue, Masafusa
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We detect 20 $z=7.0$ Ly$α$ emitter (LAE) candidates to $L({\rm Ly}α) \geq 2 \times 10^{42}$ erg s$^{-1}$ or $0.3$ $L^*_{z=7}$ and in $6.1\times 10^5$ Mpc$^3$ volume in the Subaru Deep Field and the Subaru/XMM-Newton Deep Survey field by 82 and 37 hours of Subaru Suprime-Cam narrowband NB973 and reddest optical $y$-band imaging. We compare their Ly$α$ and UV luminosity functions (LFs) and densities and Ly$α$ equivalent widths (EWs) to those of $z=5.7$, 6.6 and 7.3 LAEs from previous Suprime-Cam surveys. The Ly$α$ LF (density) rapidly declines by a factor of $\times$1.5 (1.9) in $L({\rm Ly}α)$ at $z=5.7-6.6$ (160 Myr), $\times$1.5 (1.6) at $z=6.6-7.0$ (60 Myr) at the faint end and $\times$2.0 (3.8) at $z=7.0-7.3$ (40 Myr). Also, in addition to the systematic decrease in EW at $z=5.7-6.6$ previously found, 2/3 of the $z=7.0$ LAEs detected in the UV continuum exhibit lower EWs than the $z=6.6$ ones. Moreover, while the UV LF and density do not evolve at $z=5.7-6.6$, they modestly decline at $z=6.6-7.0$, implying galaxy evolution contributing to the decline of the Ly$α$ LF. Comparison of the $z=7.0$ Ly$α$ LF to the one predicted by an LAE evolution model further reveals that galaxy evolution alone cannot explain all the decline of Ly$α$ LF. If we attribute the discrepancy to Ly$α$ attenuation by neutral hydrogen, the intergalactic medium transmission of Ly$α$ photons at $z=7.0$ would be $T_{{\rm Ly}α}^{\rm IGM} \leq 0.6-0.7$. It is lower (higher) than $T_{{\rm Ly}α}^{\rm IGM}$ at $z=6.6$ (7.3) derived by previous studies, suggesting rapid increase in neutral fraction at $z > 6$.
description: 37 Pages, 22 Figures, 10 Tables, Accepted for publication in ApJ
Layer formation in horizontally forced stratified turbulence: connecting exact coherent structures to linear instabilities
Creators: name: Lucas, Dan
name: Caulfield, C. P.
name: Kerswell, Rich R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We consider turbulence in a stratified 'Kolmogorov' flow, driven by horizontal shear in the form of sinusoidal body forcing in the presence of an imposed background linear stable stratification in the third direction. This flow configuration allows the controlled investigation of the formation of coherent structures, which here organise the flow into horizontal layers by inclining the background shear as the strength of the stratifica- tion is increased. By numerically converging exact steady states from direct numerical simulations of chaotic flow, we show, for the first time, a robust connection between linear theory predicting instabilities from infinitesimal perturbations to the robust finite amplitude nonlinear layered state observed in the turbulence. We investigate how the observed vertical length scales are related to the primary linear instabilities and compare to previously considered examples of shear instability leading to layer formation in other horizontally sheared flows.
TCGAN: Convolutional Generative Adversarial Network for Time Series Classification and Clustering
Creators: name: Huang, Fanling
name: Deng, Yangdong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Recent works have demonstrated the superiority of supervised Convolutional Neural Networks (CNNs) in learning hierarchical representations from time series data for successful classification. These methods require sufficiently large labeled data for stable learning, however acquiring high-quality labeled time series data can be costly and potentially infeasible. Generative Adversarial Networks (GANs) have achieved great success in enhancing unsupervised and semi-supervised learning. Nonetheless, to our best knowledge, it remains unclear how effectively GANs can serve as a general-purpose solution to learn representations for time series recognition, i.e., classification and clustering. The above considerations inspire us to introduce a Time-series Convolutional GAN (TCGAN). TCGAN learns by playing an adversarial game between two one-dimensional CNNs (i.e., a generator and a discriminator) in the absence of label information. Parts of the trained TCGAN are then reused to construct a representation encoder to empower linear recognition methods. We conducted comprehensive experiments on synthetic and real-world datasets. The results demonstrate that TCGAN is faster and more accurate than existing time-series GANs. The learned representations enable simple classification and clustering methods to achieve superior and stable performance. Furthermore, TCGAN retains high efficacy in scenarios with few-labeled and imbalanced-labeled data. Our work provides a promising path to effectively utilize abundant unlabeled time series data.
title: Computational Investigation on the Adsorption and Photodegradation of Glyphosate in its zwitterionic form on a Rutile (110) Titanium Dioxide Surface
Creators: name: Brauer, Jakob
name: Gerhards, Luca
name: Klüner, Thorsten
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
In times of steadily increasing demand for food due to the continuous growth of the world population, herbicides like glyphosate are heavily used to ensure the supply of crops all around the world [C. Benbrook, Environ. Sci. Eur. 28, 2016, 3.]. Therefore, the leaching of these chemicals into ground and surface waters has become an increasingly troubling issue since several ways of exposure to humans are possible [Singh et al. Environ. Chem. Lett. 18, 2020, 663.].

The investigation of possibilities for adsorption and degradation of pollutants like glyphosate can be approached from a computational point of view to provide insight while being less expensive than experimental studies. Earlier studies using DFT and higher-level wave function methods have proven to give valuable results and show the ability of TiO2 to fixate and degrade the glyphosate dianion [L. Gerhards, PhD thesis, Carl-von-Ossietzky-Universität Oldenburg, 2021; Balzaretti et al. ChemRxiv, 2021, DOI 10.26434/chemrxiv.14465436.v1].

In this work the adsorption, photoexcitation and degradation of zwitterionic glyphosate on a rutile (110) surface is considered and different adsorption geometries and degradation pathways are evaluated using DFT methods. Additionally, the effect of an acidic environment on the surface and the adsorption is investigated. The calculations have shown that the adsorbed zwitterion is hardly affected by electronic excitation of the system, furthermore several degradation pathways have been evaluated, showing that the zwitterion tends to behave and degrade differently from the dianion on the surface, being in agreement with experimental data [Muneer et al. Int. J. Photoenergy, 2008, 2008, 1.].
British Gallup Poll CQ 572
Creators: name: Social Surveys (Gallup Poll) Limited
Publisher: name: Roper Center for Public Opinion Research
Year: 2022

description: Government approval (1); James Callaghan approval (1); Margaret Thatcher approval (1); Daniel Steel approval (1); last general election (2); urgent problems (2); party to handle problems (1); next general election (2); government price policy (14); carpeting (2); kitchen furniture (23); bedroom furniture (23); sun tan products (27); mattress brands (13); appliances in home (63); ironing (7); cheesecake (71); radio habits (24); vacation abroad (44).
Dynamically assisted Sauter-Schwinger effect - non-perturbative versus perturbative aspects
Creators: name: Torgrimsson, Greger
name: Schneider, Christian
name: Oertel, Johannes
name: Schützhold, Ralf
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The Sauter-Schwinger effect predicts the creation of electron-positron pairs out of the quantum vacuum by a strong and slowly varying electric field. This effect can be dynamically assisted by an additional weaker time-dependent field, which may drastically enhance the pair-creation probability. In previous studies, it has been found that the enhancement may crucially depend on the temporal shape of this weaker pulse, e.g., a Gaussian profile $\exp\{-(ωt)^2\}$ or a Sauter pulse $1/\cosh^2(ωt)$ behave quite differently. In order to understand this difference, we make a perturbative expansion in terms of the weaker field while treating the strong electric field non-perturbatively. For a large class of profiles including the Sauter pulse, already the sum of the zeroth-order and the first-order amplitudes of this perturbative expansion yields good agreement. For other cases, such as a Gaussian or sinusoidal profile, this is not true in general and higher orders can yield the dominant contribution - where the dominant order depends on the chosen parameters. Our findings are confirmed by numerical simulations and help us to sort previous results into a bigger picture.
description: 25 pages, 6 figures. Version 2: minor changes to improve presentation, matches journal version
A Spatiotemporal Deep Neural Network for Fine-Grained Multi-Horizon Wind Prediction
Creators: name: Huang, Fanling
name: Deng, Yangdong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: The prediction of wind in terms of both wind speed and direction, which has a crucial impact on many real-world applications like aviation and wind power generation, is extremely challenging due to the high stochasticity and complicated correlation in the weather data. Existing methods typically focus on a sub-set of influential factors and thus lack a systematic treatment of the problem. In addition, fine-grained forecasting is essential for efficient industry operations, but has been less attended in the literature. In this work, we propose a novel data-driven model, Multi-Horizon SpatioTemporal Network (MHSTN), generally for accurate and efficient fine-grained wind prediction. MHSTN integrates multiple deep neural networks targeting different factors in a sequence-to-sequence (Seq2Seq) backbone to effectively extract features from various data sources and produce multi-horizon predictions for all sites within a given region. MHSTN is composed of four major modules. First, a temporal module fuses coarse-grained forecasts derived by Numerical Weather Prediction (NWP) and historical on-site observation data at stations so as to leverage both global and local atmospheric information. Second, a spatial module exploits spatial correlation by modeling the joint representation of all stations. Third, an ensemble module weighs the above two modules for final predictions. Furthermore, a covariate selection module automatically choose influential meteorological variables as initial input. MHSTN is already integrated into the scheduling platform of one of the busiest international airports of China. The evaluation results demonstrate that our model outperforms competitors by a significant margin.
Towards Better Multi-modal Keyphrase Generation via Visual Entity Enhancement and Multi-granularity Image Noise Filtering
Creators: name: Dong, Yifan
name: Wu, Suhang
name: Meng, Fandong
name: Zhou, Jie
name: Wang, Xiaoli
name: Lin, Jianxin
name: Su, Jinsong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Computation and Language (cs.CL)
subject: Multimedia (cs.MM)
subject: FOS: Computer and information sciences

description: Multi-modal keyphrase generation aims to produce a set of keyphrases that represent the core points of the input text-image pair. In this regard, dominant methods mainly focus on multi-modal fusion for keyphrase generation. Nevertheless, there are still two main drawbacks: 1) only a limited number of sources, such as image captions, can be utilized to provide auxiliary information. However, they may not be sufficient for the subsequent keyphrase generation. 2) the input text and image are often not perfectly matched, and thus the image may introduce noise into the model. To address these limitations, in this paper, we propose a novel multi-modal keyphrase generation model, which not only enriches the model input with external knowledge, but also effectively filters image noise. First, we introduce external visual entities of the image as the supplementary input to the model, which benefits the cross-modal semantic alignment for keyphrase generation. Second, we simultaneously calculate an image-text matching score and image region-text correlation scores to perform multi-granularity image noise filtering. Particularly, we introduce the correlation scores between image regions and ground-truth keyphrases to refine the calculation of the previously-mentioned correlation scores. To demonstrate the effectiveness of our model, we conduct several groups of experiments on the benchmark dataset. Experimental results and in-depth analyses show that our model achieves the state-of-the-art performance. Our code is available on https://github.com/DeepLearnXMU/MM-MKP.
description: Accepted In Proceedings of the 31st ACM International Conference on Multimedia (MM' 23)
Nonlinear approximation with nonstationary Gabor frames
Creators: name: Ottosen, Emil Solsbæk
name: Nielsen, Morten
Publisher: name: arXiv
Year: 2017
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 41A17, 42B35, 42C15, 42C40

description: We consider sparseness properties of adaptive time-frequency representations obtained using nonstationary Gabor frames (NSGFs). NSGFs generalize classical Gabor frames by allowing for adaptivity in either time or frequency. It is known that the concept of painless nonorthogonal expansions generalizes to the nonstationary case, providing perfect reconstruction and an FFT based implementation for compactly supported window functions sampled at a certain density. It is also known that for some signal classes, NSGFs with flexible time resolution tend to provide sparser expansions than can be obtained with classical Gabor frames. In this article we show, for the continuous case, that sparseness of a nonstationary Gabor expansion is equivalent to smoothness in an associated decomposition space. In this way we characterize signals with sparse expansions relative to NSGFs with flexible time resolution. Based on this characterization we prove an upper bound on the approximation error occurring when thresholding the coefficients of the corresponding frame expansions. We complement the theoretical results with numerical experiments, estimating the rate of approximation obtained from thresholding the coefficients of both stationary and nonstationary Gabor expansions.
description: 19 pages, 2 figures
Effect of doping on the intersubband absorption in Si- and Ge-doped GaN/AlN heterostructures
Creators: name: Ajay, A.
name: Lim, C. B.
name: Browne, D. A.
name: Polaczynski, J.
name: Bellet-Amalric, E.
name: Bleuse, J.
name: Hertog, M. I. den
name: Monroy, E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this paper, we study band-to-band and intersubband characteristics of GaN/AlN heterostructures (planar and nanowires) structurally designed to absorb in the short-wavelength infrared region, particularly at 1.55 microns. We compare the effect of doping the GaN sections with Si and Ge, and we discuss the variation of free-carrier screening with the doping density and well/nanodisk size. We observe that nanowire heterostructures consistently present longer photoluminescence decay times than their planar counterparts, which supports the existence of an in-plane piezoelectric field associated to the shear component of the strain tensor, leading to lateral electron-hole separation. We report intersubband absorption covering 1.45 microns to 1.75 microns using Ge-doped quantum wells, with comparable performance to well-studied Si-doped planar heterostructures. We also report comparable intersubband absorption in Si- and Ge-doped nanowire heterostructures indicating that the choice of dopant is not an intrinsic barrier for observing intersubband phenomena. In addition, we calculate the spectral shift of the intersubband absorption due to many body effects as a function of the doping concentration.