cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Inferring asymmetric limb cloudiness on exoplanets from transit light curves
Creators: name: von Paris, P.
name: Gratier, P.
name: Bordé, P.
name: Leconte, J.
name: Selsis, F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Clouds have been shown to be present in many exoplanetary atmospheres. Cloud formation modeling predicts considerable inhomogeneities of cloud cover, consistent with optical phase curve observations. However, optical phase curves cannot resolve some existing degeneracies between cloud location and cloud optical properties. We present a conceptually simple technique to detect inhomogeneous cloud cover on exoplanets. Such an inhomogeneous cloud cover produces an asymmetric primary transit of the planet in front of the host star. Asymmetric transits produce characteristic residuals compared to a standard symmetric model. Furthermore, bisector spans can be used to determine asymmetries in the transit light curve. We apply a model of asymmetric transits to the light curves of HAT-P-7b, Kepler-7b and HD209458b and search for possible cloud signatures. The nearly uninterrupted Kepler photometry is particularly well-suited for this method since it allows for a very high time resolution. We do not find any statistically sound cloud signature in the data of the considered planets. For HAT-P-7b, a tentative detection of an asymmetric cloud cover is found, consistent with analysis of the optical phase curve. Based on Bayesian probability arguments, a symmetric model with an offset in the transit ephemeris remains, however, the most viable model. Still, this work demonstrates that for suitable targets, namely low-gravity planets around bright stars, the method can be used to constrain cloud cover characteristics and is thus a helpful additional tool to study exoplanetary atmospheres.
description: accepted for publication in Astronomy&Astrophysics on Feb. 12th, 11 pages, 20 figures, 2 tables, + Appendix
Charge Transfer Properties Through Graphene for Applications in Gaseous Detectors
Creators: name: Franchino, S.
name: Gonzalez-Diaz, D.
name: Hall-Wilton, R.
name: Jackman, R. B.
name: Muller, H.
name: Nguyen, T. T.
name: de Oliveira, R.
name: Oliveri, E.
name: Pfeiffer, D.
name: Resnati, F.
name: Ropelewski, L.
name: Smith, J.
name: van Stenis, M.
name: Streli, C.
name: Thuiner, P.
name: Veenhof, R.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Graphene is a single layer of carbon atoms arranged in a honeycomb lattice with remarkable mechanical and electrical properties. Regarded as the thinnest and narrowest conductive mesh, it has drastically different transmission behaviours when bombarded with electrons and ions in vacuum. This property, if confirmed in gas, may be a definitive solution for the ion back-flow problem in gaseous detectors. In order to ascertain this aspect, graphene layers of dimensions of about 2x2cm$^2$, grown on a copper substrate, are transferred onto a flat metal surface with holes, so that the graphene layer is freely suspended. The graphene and the support are installed into a gaseous detector equipped with a triple Gaseous Electron Multiplier (GEM), and the transparency properties to electrons and ions are studied in gas as a function of the electric fields. The techniques to produce the graphene samples are described, and we report on preliminary tests of graphene-coated GEMs.
description: 4pages, 3figures, 13th Pisa Meeting on Advanced Detectors
Conditions for observing emergent SU(4) symmetry in a double quantum dot
Creators: name: Nishikawa, Yunori
name: Curtin, Oliver J.
name: Hewson, Alex C.
name: Crow, Daniel J. G.
name: Bauer, Johannes
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We analyze conditions for the observation of a low energy SU(4) fixed point in capacitively coupled quantum dots. One problem, due to dots with different couplings to their baths, has been considered by Tosi, Roura-Bas and Aligia (2015). They showed how symmetry can be effectively restored via the adjustment of individual gates voltages, but they make the assumption of infinite on-dot and inter-dot interaction strengths. A related problem is the difference in the magnitudes between the on-dot and interdot strengths for capacitively coupled quantum dots. Here we examine both factors, based on a two site Anderson model, using the numerical renormalization group to calculate the local spectral densities on the dots and the renormalized parameters that specify the low energy fixed point. Our results support the conclusions of Tosi et al. that low energy SU(4) symmetry can be restored, but asymptotically achieved only if the inter-dot interaction $U_{12}$ is greater than or of the order of the band width of the coupled conduction bath $D$, which might be difficult to achieve experimentally. By comparing the SU(4) Kondo results for a total dot occupation $n_{\rm tot}=1$ and $n_{\rm tot}=2$ we conclude that the temperature dependence of the conductance is largely determined by the constraints of the Friedel sum rule rather than the SU(4) symmetry and suggest that an initial increase of the conductance with temperature is a distinguishing characteristic feature of an $n_{\rm tot}=1$ universal SU(4) fixed point.
description: 14 pages and 20 figures
Roles for interleukin-11 in human trophoblast function
Creators: name: Paiva., Premila
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Gaia21bty: An EXor lightcurve exhibiting an FUor spectrum
Creators: name: Siwak, Michał
name: Hillenbrand, Lynne A.
name: Kóspál, Ágnes
name: Ábrahám, Péter
name: Giannini, Teresa
name: De, Kishalay
name: Moór, Attila
name: Szilágyi, Máté
name: Janík, Jan
name: Koen, Chris
name: Park, Sunkyung
name: Nagy, Zsófia
name: de Miera, Fernando Cruz-Sáenz
name: Fiorellino, Eleonora
name: Marton, Gábor
name: Kun, Mária
name: Lucas, Philip W.
name: Udalski, Andrzej
name: Szabó, Zsófia Marianna
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Gaia21bty, a pre-main sequence star that previously had shown aperiodic dips in its light curve, underwent a considerable $ΔG\approx2.9$ mag brightening that occurred over a few months between 2020 October - 2021 February. The Gaia lightcurve shows that the star remained near maximum brightness for about $4-6$ months, and then started slowly fading over the next 2 years, with at least three superimposed $\sim$1 mag sudden rebrightening events. Whereas the amplitude and duration of the maximum is typical for EXors, optical and near-infrared spectra obtained at the maximum are dominated by features which are typical for FUors. Modelling of the accretion disc at the maximum indicates that the disc bolometric luminosity is 43 L$_{\odot}$ and the mass accretion rate is $2.5\times10^{-5}$ M$_{\odot}$ yr$^{-1}$, which are typical values for FUors even considering the large uncertainty in the distance ($1.7_{-0.4}^{+0.8}$ kpc). Further monitoring is necessary to understand the cause of the quick brightness decline, the rebrightening, and the other post-outburst light changes, as our multi-colour photometric data suggest that they could be caused by a long and discontinuous obscuration event. We speculate that the outburst might have induced large-scale inhomogeneous dust condensations in the line of sight leading to such phenomena, whilst the FUor outburst continues behind the opaque screen.
description: Accepted to MNRAS
Anomaly Detection with Selective Dictionary Learning
Creators: name: Ilie-Ablachim, Denis C.
name: Dumitrescu, Bogdan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: In this paper we present new methods of anomaly detection based on Dictionary Learning (DL) and Kernel Dictionary Learning (KDL). The main contribution consists in the adaption of known DL and KDL algorithms in the form of unsupervised methods, used for outlier detection. We propose a reduced kernel version (RKDL), which is useful for problems with large data sets, due to the large kernel matrix. We also improve the DL and RKDL methods by the use of a random selection of signals, which aims to eliminate the outliers from the training procedure. All our algorithms are introduced in an anomaly detection toolbox and are compared to standard benchmark results.
Quantifying Uncertainties in the 2004 Sumatra-Andaman Earthquake Source Parameters by Stochastic Inversion
Creators: name: Gopinathan, Devaraj
name: Venugopal, Mamatha
name: Roy, Debasish
name: Rajendran, Kusala
name: Guillas, Serge
name: Dias, Frederic
Publisher: name: arXiv
Year: 2016
Subjects: subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: Usual inversion for earthquake source parameters from tsunami wave data incorporates subjective elements. Noisy and possibly insufficient data also results in instability and non-uniqueness in most deterministic inversions. Here we employ the satellite altimetry data for the 2004 Sumatra-Andaman tsunami event to invert the source parameters. Using a finite fault model that represents the extent of rupture and the geometry of the trench, we perform a non-linear joint inversion of the slips, rupture velocities and rise times with minimal a priori constraints. Despite persistently good waveform fits, large variance and skewness in the joint parameter distribution constitute a remarkable feature of the inversion. These uncertainties suggest the need for objective inversion strategies that should incorporate more sophisticated physical models in order to significantly improve the performance of early warning systems.
A room temperature CO$_2$ line list with ab initio computed intensities
Creators: name: Zak, Emil
name: Tennyson, Jonathan
name: Polyansky, Oleg L.
name: Lodi, Lorenzo
name: Zobov, Nikolay F.
name: Tashkun, Sergey A.
name: Perevalov, Valery I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Atmospheric carbon dioxide concentrations are being closely monitored by remote sensing experiments which rely on knowing line intensities with an uncertainty of 0.5% or better. We report a theoretical study providing rotation-vibration line intensities substantially within the required accuracy based on the use of a highly accurate {\it ab initio} dipole moment surface (DMS). The theoretical model developed is used to compute CO$_2$ intensities with uncertainty estimates informed by cross comparing line lists calculated using pairs of potential energy surfaces (PES) and DMS's of similar high quality. This yields lines sensitivities which are utilized in reliability analysis of our results. The final outcome is compared to recent accurate measurements as well as the HITRAN2012 database. Transition frequencies are obtained from effective Hamiltonian calculations to produce a comprehensive line list covering all $^{12}$C$^{16}$O$_2$ transitions below 8000 cm$^{-1}$ and stronger than 10$^{-30}$ cm / molecule at $T=296$~K
Fractional boundary charges in quantum dot arrays with density modulation
Creators: name: Park, Jin-Hong
name: Yang, Guang
name: Klinovaja, Jelena
name: Stano, Peter
name: Loss, Daniel
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show that fractional charges can be realized at the boundaries of a linear array of tunnel coupled quantum dots in the presence of a periodically modulated onsite potential. While the charge fractionalization mechanism is similar to the one in polyacetylene, here the values of fractional charges can be tuned to arbitrary values by varying the phase of the onsite potential or the total number of dots in the array. We also find that the fractional boundary charges, unlike the in-gap bound states, are stable against static random disorder. We discuss the minimum array size where fractional boundary charges can be observed.
description: 10 pages, 10 figures
Asymptotically locally flat spacetimes and dynamical black flowers in three dimensions
Creators: name: Barnich, Glenn
name: Troessaert, Cédric
name: Tempo, David
name: Troncoso, Ricardo
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The theory of massive gravity proposed by Bergshoeff, Hohm and Townsend is considered in the special case of the pure irreducibly fourth order quadratic Lagrangian. It is shown that the asymptotically locally flat black holes of this theory can be consistently deformed to "black flowers" that are no longer spherically symmetric. Moreover, we construct radiating spacetimes settling down to these black flowers in the far future. The generic case can be shown to fit within a relaxed set of asymptotic conditions as compared to the ones of general relativity at null infinity, while the asymptotic symmetries remain the same. Conserved charges as surface integrals at null infinity are constructed following a covariant approach, and their algebra represents BMS$_{3}$, but without central extensions. For solutions possessing an event horizon, we derive the first law of thermodynamics from these surface integrals.
description: 14 pages, no figures
Analysis of mutant mice having the targeted expression of a toxin gene to D1-dopamine receptor expressing neurons
Creators: name: Padungchaichot., Poolpol
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Path probability of stochastic motion: A functional approach
Creators: name: Hattori, Masayuki
name: Abe, Sumiyoshi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: General Finance (q-fin.GN)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: FOS: Economics and business

description: The path probability of a particle undergoing stochastic motion is studied by the use of functional technique, and the general formula is derived for the path probability distribution functional. The probability of finding paths inside a tube/band, the center of which is stipulated by a given path, is analytically evaluated in a way analogous to continuous measurements in quantum mechanics. Then, the formalism developed here is applied to the stochastic dynamics of stock price in finance.
description: 19 pages, 2 figures
title: Amtliches Mitteilungsblatt der BTU Cottbus–Senftenberg, 2023,22 (29.09.2023)
Creators: name: (:Unav)
Publisher: name: BTU  Cottbus - Senftenberg
Year: 2023
Subjects: subject: 000 Informatik, Informationswissenschaft, allgemeine Werke

description: Fachspezifische Prüfungs- und Studienordnung für den Studiengang Lehramt Primarstufe Bachelor (PrimPStO-BA) vom 28. September 2023
description: Amtliches Mitteilungsblatt der BTU Cottbus–Senftenberg; 2023, H. 22
The Hyperon Puzzle in Neutron Stars
Creators: name: Bombaci, Ignazio
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The so called "hyperon puzzle", i.e. the difficulty to reconcile the measured masses of neutron stars (NSs) with the presence of hyperons in their interiors, is one of the hot topics in astrophysics which is stimulating copious experimental and theoretical research in hypernuclear physics. After illustrating the origin of the hyperon puzzle, I discuss some of its possible solutions, and particularly those related to the role of hyperonic two- and three-body interactions on the equation of state of dense matter. Afterward, I discuss a possibility to circumvent the hyperon puzzle allowing for the presence of strangeness in NSs in the form of deconfined strange quark matter, and thus considering the so called quark stars, i.e. hybrid stars or strange stars. Finally I discuss the astrophysical consequences of the possible conversion process of an hadronic star to a quark star.
description: Invited keynote talk at the Topical Session "Hyperon puzzle in Neutron Stars" at the 12th International Conference on Hypernuclear and Strange Particle Physics (HYP2015), September 7-12, 2015, Sendai, Japan. arXiv admin note: text overlap with arXiv:1601.04559
Measurement of the Newton's cooling law time-constant by Arduino: an idea for STEM education in High Schools
Creators: name: Casaburo, Fausto
Publisher: name: arXiv
Year: 2021
Subjects: subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: Commercial electronic measuring devices used in physics usually have high costs. In recent years, thanks to its low cost and the high number of available sensors, the Arduino board has been used for many educational purposes in physics education. In this paper a method to measure the Newton's cooling law time-constant by the Arduino board is presented.
NuSTAR discovery of a cyclotron line in the accreting X-ray pulsar IGR J16393-4643
Creators: name: Bodaghee, Arash
name: Tomsick, John A.
name: Fornasini, Francesca A.
name: Krivonos, Roman
name: Stern, Daniel
name: Mori, Kaya
name: Rahoui, Farid
name: Boggs, Steven E.
name: Christensen, Finn E.
name: Craig, William W.
name: Hailey, Charles J.
name: Harrison, Fiona A.
name: Zhang, William W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The high-mass X-ray binary and accreting X-ray pulsar IGR J16393-4643 was observed by NuSTAR in the 3-79 keV energy band for a net exposure time of 50 ks. We present the results of this observation which enabled the discovery of a cyclotron resonant scattering feature with a centroid energy of 29.3(+1.1/-1.3) keV. This allowed us to measure the magnetic field strength of the neutron star for the first time: B = (2.5+/-0.1)e12 G. The known pulsation period is now observed at 904.0+/-0.1 s. Since 2006, the neutron star has undergone a long-term spin-up trend at a rate of P' = -2e-8 s/s (-0.6 s per year, or a frequency derivative of nu' = 3e-14 Hz/s ). In the power density spectrum, a break appears at the pulse frequency which separates the zero slope at low frequency from the steeper slope at high frequency. This addition of angular momentum to the neutron star could be due to the accretion of a quasi-spherical wind, or it could be caused by the transient appearance of a prograde accretion disk that is nearly in corotation with the neutron star whose magnetospheric radius is around 2e8 cm.
description: Accepted for publication in the Astrophysical Journal, 7 pages, 8 figures, 2 tables
Combinatorial Methods in Grid based Meshing
Creators: name: Stromberg, Henrik
name: Mayer-Eichberger, Valentin
name: Lohrengel, Armin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computational Geometry (cs.CG)
subject: FOS: Computer and information sciences
subject: J.6

description: This paper describes a novel method of generating hex-dominant meshes using pre-computed optimal subdivisions of the unit cube in a grid-based approach. Our method addresses geometries that are standard in mechanical engineering and often must comply with the restrictions of subtractive manufacturability. A central component of our method is the set of subdivisions we pre-compute with Answer Set Programming. Despite being computationally expensive, we obtain optimal meshes of up to 35 nodes available to our method in a template fashion. The first step in our grid-based method generates a coarse Precursor Mesh for meshing complete parts representing the bar stock. Then, the resulting mesh is generated in a subtractive manner by inserting and fitting the pre-generated subdivisions into the Precursor Mesh. This step guarantees that the elements are of good quality. In the final stage, the mesh nodes are mapped to geometric entities of the target geometry to get an exact match. We demonstrate our method with multiple examples showing the strength of this approach.
The quantum theory of time: a calculus for q-numbers
Creators: name: Kuypers, Samuel
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In quantum theory, physical systems are usually assumed to evolve relative to a c-number time. This c-number time is unphysical and has turned out to be unnecessary for explaining dynamics: in the timeless approach to quantum theory developed by Page & Wootters (1983), subsystems of a stationary universe can instead evolve relative to a 'clock', which is a quantum system with a q-number time observable. Page & Wootters formulated their construction in the Schrödinger picture and left open the possibility that the c-number time still plays an explanatory role in the Heisenberg picture. I formulate their construction in the Heisenberg picture and demonstrate that c-number time is completely unnecessary in that picture, too. When the Page-Wootters construction is formulated in the Heisenberg picture, the descriptors of physical systems are functions of the clock's q-number time, and derivatives with respect to this q-number time can be defined in terms of the clock's algebra of observables, resulting in a calculus for q-numbers.
Epidemiology of vancomycin resistant enterococcus in Australia
Creators: name: Padiglione., Alexander
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Grassmann Phase Space Methods for Fermions. II. Field Theory
Creators: name: Dalton, Bryan J
name: Jeffers, John
name: Barnett, Stephen M
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In both quantum optics and cold atom physics, the behaviour of bosonic photons and atoms is often treated using phase space methods, where mode annihilation and creation operators are represented by c-number phase space variables, with the density operator equivalent to a distribution function of these variables. The anti-commutation rules for fermion annihilation, creation operators suggests the possibility of using anti-commuting Grassmann variables to represent these operators. However, in spite of the seminal work by Cahill and Glauber and a few applications, the use of Grassmann phase space methods in quantum - atom optics to treat fermionic systems is rather rare, though fermion coherent states using Grassmann variables are widely used in particle physics. This paper presents a phase space theory for fermion systems based on distribution functionals, which replace the density operator and involve Grassmann fields representing anti-commuting fermion field annihilation, creation operators. It is an extension of a previous phase space theory paper for fermions (Paper I) based on separate modes, in which the density operator is replaced by a distribution function depending on Grassmann phase space variables which represent the mode annihilation and creation operators. This further development of the theory is important for the situation when large numbers of fermions are involved, resulting in too many modes to treat separately. Here Grassmann fields, distribution functionals, functional Fokker-Planck equations and Ito stochastic field equations are involved. Typical applications to a trapped Fermi gas of interacting spin 1/2 fermionic atoms and to multi-component Fermi gases with non-zero range interactions are presented, showing that the Ito stochastic field equations are local in these cases. Solutions for spin 1/2 fermions either free or in lattices are found.
description: 63 pages. 0 figures. Version 2. References updated
Tables and Model Outputs from Tail shape and the swimming speed of sharks
Creators: name: Iliou, Anthony S.
name: Vanderwright, Wade
name: Harding, Lucy
name: Jacoby, David M. P.
name: Payne, Nicholas L.
name: Dulvy, Nicholas K.
Publisher: name: The Royal Society
Year: 2023
Subjects: Ecology not elsewhere classified

description: A word document containing tables of trait values for each shark species, and model outputs.
Computing Jet Transport Coefficients On The Lattice
Creators: name: Kumar, Amit
name: Majumder, Abhijit
name: Soudi, Ismail
name: Weber, Johannes H.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The leading jet transport coefficients $\hat{q}$ or $\hat{e}_{2}$ encode transverse or longitudinal momentum broadening of a hard parton traversing a hot medium. Understanding their temperature dependence is key to appreciating the observed suppression of high-transverse momentum probes at RHIC or LHC collision energies. We present a first continuum extrapolated result of $\hat{q}$ computed on pure SU(3) lattices with non-trivial temperature dependence different from the weak-coupling expectation. We discuss our formalism and its challenges and status in view of obtaining $\hat{e}_{2}$ or of unquenching the calculation. We consider a hard quark subject to a single scattering on the plasma. The transport coefficients are factorized in terms of matrix elements given as integrals of non-local gauge-covariant gluon field-strength field-strength correlators. After the analytic continuation to the deep-Euclidean region, the hard scale permits to recast these as a series of local, gauge-invariant operators. The renormalized leading-twist term in this expansion is closely related to static quantities, and is computed on pure SU(3) lattices ($N_τ=4,~6,~8,$ and $10$) for a wide range of temperatures, ranging from 200MeV < T < 1GeV. Our estimate for the unquenched result in $2+1$-flavor QCD has very similar features.
description: 6 pages, 1 figure, HardProbes2023, 26-31 March 2023, Aschaffenburg, Germany
Covariant Hyperbolization of Force-free Electrodynamics
Creators: name: Carrasco, Federico
name: Reula, Oscar
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences
subject: 35L02, 35L03, 85A04

description: Force-Free Flectrodynamics (FFE) is a non-linear system of equations modeling the evolution of the electromagnetic field, in the presence of a magnetically dominated relativistic plasma. This configuration arises on several astrophysical scenarios, which represent exciting laboratories to understand physics in extreme regimes. We show that this system, when restricted to the correct constraint submanifold, is symmetric hyperbolic. In numerical applications is not feasible to keep the system in that submanifold, and so, it is necessary to analyze its structure first in the tangent space of that submanifold and then in a whole neighborhood of it. As already shown by Pfeiffer, a direct (or naive) formulation of this system (in the whole tangent space) results in a weakly hyperbolic system of evolution equations for which well-possednes for the initial value formulation does not follows. Using the generalized symmetric hyperbolic formalism due to Geroch, we introduce here a covariant hyperbolization for the FFE system. In fact, in analogy to the usual Maxwell case, a complete family of hyperbolizers is found, both for the restricted system on the constraint submanifold as well as for a suitably extended system defined in a whole neighborhood of it. A particular symmetrizer among the family is then used to write down the pertaining evolution equations, in a generic ($3+1$)-decomposition on a background spacetime. Interestingly, it turns out that for a particular choice of the lapse and shift functions of the foliation, our symmetrized system reduces to the one found by Pfeiffer. Finally we analyze the characteristic structure of the resulting evolution system.
description: 15 pages
Dual Relativistic Quantum Mechanics I
Creators: name: Gill, Tepper L.
name: de Parga, Gonzalo Ares
name: Morris, Trey
name: Wade, Mamadou
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: In \cite{2} it was shown that Einstein's special theory of relativity and Maxwell's field theory have mathematically equivalent dual versions. The dual versions arise from an identity relating observer time to proper time as a contact transformation on configuration space, which leaves phase space invariant. The special theory has a dual version in the sense that, for any set of $n$ particles, every observer has two unique sets of global variables $({\bf{X}}, t)$ and $({\bf{X}}, τ)$ to describe the dynamics, where ${\bf{X}}$ is the (unique) canonical center of mass. In the $({\bf{X}}, t)$ variables, time is relative and the speed of light is unique, while in the $({\bf{X}}, τ)$ variables, time is unique and the speed of light is relative with no upper bound. In the Maxwell case, the two sets of particle wave equations are not equivalent. The dual version contains an additional longitudinal (dissipative) radiation term that appears instantaneously with acceleration, leading to the prediction that radiation from a betatron (of any frequency) will not produce photoelectrons. A major outcome is the dual unification of Newtonian mechanics and classical electrodynamics with Einstein's special theory of relativity, without a self-energy divergency, or need of the problematic Lorentz-Dirac equation or any assumptions about the size or structure of a particle. The purpose of this paper is to introduce and develop the dual theory of relativistic quantum mechanics. We obtain three distinct dual relativistic wave equations that reduce to the Schr{ö}dinger equation when minimal coupling is turned off. We show that the dual Dirac equation provides a new formula for the anomalous magnetic moment of a charged particle. We can obtain the exact value for the electron g-factor and phenomenological values for the muon and proton g-factors.
description: arXiv admin note: text overlap with arXiv:2002.02377
Nested species interactions promote feasibility over stability during the assembly of a pollinator community
Creators: name: Saavedra, Serguei
name: Rohr, Rudolf P.
name: Olesen, Jens M.
name: Bascompte, Jordi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Popular Physics (physics.pop-ph)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: The foundational concepts behind the persistence of ecological communities have been based on two ecological properties: dynamical stability and feasibility. The former is typically regarded as the capacity of a community to return to an original equilibrium state after a perturbation in species abundances, and is usually linked to the strength of interspecific interactions. The latter is the capacity to sustain positive abundances on all its constituent species, and is linked to both interspecific interactions and species demographic characteristics. Over the last 40 years, theoretical research in ecology has emphasized the search for conditions leading to the dynamical stability of ecological communities, while the conditions leading to feasibility have been overlooked. However, thus far, we have no evidence of whether species interactions are more conditioned by the community's need to be stable or feasible. Here, we introduce novel quantitative methods and use empirical data to investigate the consequences of species interactions on the dynamical stability and feasibility of mutualistic communities. First, we demonstrate that the more nested the species interactions in a community are, the lower the mutualistic strength that the community can tolerate without losing dynamical stability. Second, we show that high feasibility in a community can be reached either with high mutualistic strength or with highly nested species interactions. Third, we find that during the assembly process of a seasonal pollinator community located at The Zackenberg Research Station (NE Greenland), a high feasibility is reached through the nested species interactions established between newcomer and resident species. Our findings imply that nested mutualistic communities promote feasibility over stability, which may suggest that the former can be key for community persistence.
Norm-1 Regularized Consensus-based ADMM for Imaging with a Compressive Antenna
Creators: name: Juesas, Juan Heredia
name: Molaei, Ali
name: Tirado, Luis
name: Blackwell, William
name: Lorenzo, Jose A Martinez
Publisher: name: arXiv
Year: 2016
Subjects: subject: Other Computer Science (cs.OH)
subject: FOS: Computer and information sciences

description: This paper presents a novel norm-one-regularized, consensus-based imaging algorithm, based on the Alternating Direction Method of Multipliers (ADMM). This algorithm is capable of imaging composite dielectric and metallic targets by using limited amount of data. The distributed capabilities of the ADMM accelerates the convergence of the imaging. Recently, a Compressive Reflector Antenna (CRA) has been proposed as a way to provide high-sensing-capacity with a minimum cost and complexity in the hardware architecture. The ADMM algorithm applied to the imaging capabilities of the Compressive Antenna (CA) outperforms current state of the art iterative reconstruction algorithms, such as Nesterov-based methods, in terms of computational cost; and it ultimately enables the use of a CA in quasi-real-time, compressive sensing imaging applications.
description: 4 pages, 4 figures
Deep Motion Prior for Weakly-Supervised Temporal Action Localization
Creators: name: Cao, Meng
name: Zhang, Can
name: Chen, Long
name: Shou, Mike Zheng
name: Zou, Yuexian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Weakly-Supervised Temporal Action Localization (WSTAL) aims to localize actions in untrimmed videos with only video-level labels. Currently, most state-of-the-art WSTAL methods follow a Multi-Instance Learning (MIL) pipeline: producing snippet-level predictions first and then aggregating to the video-level prediction. However, we argue that existing methods have overlooked two important drawbacks: 1) inadequate use of motion information and 2) the incompatibility of prevailing cross-entropy training loss. In this paper, we analyze that the motion cues behind the optical flow features are complementary informative. Inspired by this, we propose to build a context-dependent motion prior, termed as motionness. Specifically, a motion graph is introduced to model motionness based on the local motion carrier (e.g., optical flow). In addition, to highlight more informative video snippets, a motion-guided loss is proposed to modulate the network training conditioned on motionness scores. Extensive ablation studies confirm that motionness efficaciously models action-of-interest, and the motion-guided loss leads to more accurate results. Besides, our motion-guided loss is a plug-and-play loss function and is applicable with existing WSTAL methods. Without loss of generality, based on the standard MIL pipeline, our method achieves new state-of-the-art performance on three challenging benchmarks, including THUMOS'14, ActivityNet v1.2 and v1.3.
description: Accepted by IEEE Transactions on Image Processing (TIP)
Discovery of an X-ray Emitting Contact Binary System 2MASS J11201034$-$2201340
Creators: name: Hu, Chin-Ping
name: Yang, Ting-Chang
name: Chou, Yi
name: Liu, L.
name: Qian, S. -B.
name: Hui, C. Y.
name: Kong, Albert K. H.
name: Lin, L. C. C.
name: Tam, P. H. T.
name: Li, K. L.
name: Ngeow, Chow-Choong
name: Chen, W. P.
name: Ip, Wing-Huen
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report the detection of orbital modulation, a model solution, and X-ray properties of a newly discovered contact binary, 2MASS J11201034$-$2201340. We serendipitously found this X-ray point source outside the error ellipse when searching for possible X-ray counterparts of $γ$-ray millisecond pulsars among the unidentified objects detected by the {\it Fermi Gamma-ray Space Telescope}. The optical counterpart of the X-ray source (unrelated to the $γ$-ray source) was then identified using archival databases. The long-term CRTS survey detected a precise signal with a period of $P=0.28876208(56)$ days. A follow-up observation made by the SLT telescope of Lulin Observatory revealed the binary nature of the object. Utilizing archived photometric data of multi-band surveys, we construct the spectral energy distribution, which is well fitted by a K2V spectral template. The fitting result of the orbital profile using the Wilson--Devinney code suggests that 2MASS J11201034-2201340 is a short-period A-type contact binary and the more massive component has a cool spot. The X-ray emission was first noted in observations made by \swift\, then further confirmed and characterized by an \xmm\ observation. The X-ray spectrum can be described by a power law or thermal Bremsstrahlung. Unfortunately, we could not observe significant X-ray orbital modulation. Finally, according to the spectral energy distribution, this system is estimated to be 690 pc from Earth with a calculated X-ray intensity of $(0.7-1.5)\times 10^{30}$ erg s$^{-1}$, which is in the expected range of an X-ray emitting contact binary.
description: 8 pages, 7 figures, accepted for publication in The Astronomical Journal
Light sterile neutrino sensitivity of 163Ho experiments
Creators: name: Gastaldo, L.
name: Giunti, C.
name: Zavanin, E. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We explore the sensitivity of $^{163}$Ho electron capture experiments to neutrino masses in the standard framework of three-neutrino mixing and in the framework of 3+1 neutrino mixing with a sterile neutrino which mixes with the three standard active neutrinos, as indicated by the anomalies found in short-baseline neutrino oscillations experiments. We calculate the sensitivity to neutrino masses and mixing for different values of the energy resolution of the detectors, of the unresolved pileup fraction and of the total statistics of events, considering the expected values of these parameters in the two planned stages of the ECHo project (ECHo-1k and ECHo-1M). We show that an extension of the ECHo-1M experiment with the possibility to collect $10^{16}$ events will be competitive with the KATRIN experiment. This statistics will allow to explore part of the 3+1 mixing parameter space indicated by the global analysis of short-baseline neutrino oscillation experiments. In order to cover all the allowed region, a statistics of about $10^{17}$ events will be needed.
description: 11 pages
Towards merged-element transmons using silicon fins: the FinMET
Creators: name: Goswami, Aranya
name: McFadden, Anthony P.
name: Zhao, Tongyu
name: Inbar, Hadass S.
name: Dong, Jason T.
name: Zhao, Ruichen
name: McRae, Corey Rae
name: Simmonds, Raymond W.
name: Palmstrøm, Christopher J.
name: Pappas, David P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: A merged-element transmon (MET) device, based on silicon (Si) fins, is proposed and the first steps to form such a "FinMET" are demonstrated. This new application of fin technology capitalizes on the anisotropic etch of Si(111) relative to Si(110) to define atomically flat, high aspect ratio Si tunnel barriers with epitaxial superconductor contacts on the parallel side-wall surfaces. This process circumvents the challenges associated with the growth of low-loss insulating barriers on lattice matched superconductors. By implementing low-loss, intrinsic float-zone Si as the barrier material rather than commonly used, potentially lossy AlOx, the FinMET is expected to overcome problems with standard transmons by (1) reducing dielectric losses, (2) minimizing the formation of two-level system spectral features, (3) exhibiting greater control over barrier thickness and qubit frequency spread, especially when combined with commercial fin fabrication and atomic-layer digital etching; (4) potentially reducing the footprint by several orders of magnitude; and (5) allowing scalable fabrication. Here, as a first step to making such a device, the fabrication of Si fin capacitors on Si(110) substrates with shadow-deposited Al electrodes is demonstrated. These fin capacitors are then fabricated into lumped element resonator circuits and probed using low-temperature microwave measurements. Further thinning of silicon junctions towards the tunneling regime will enable the scalable fabrication of FinMET devices based on existing silicon technology, while simultaneously avoiding lossy amorphous dielectrics for the tunnel barriers.
Two-dimensional crossover and strong coupling of plasmon excitations in arrays of one-dimensional atomic wires
Creators: name: Lichtenstein, Timo
name: Aulbach, Julian
name: Schäfer, Jörg
name: Claessen, Ralph
name: Tegenkamp, Christoph
name: Pfnür, Herbert
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The collective electronic excitations of arrays of Au chains on regularly stepped Si(553) and Si(775) surfaces were studied using electron loss spectroscopy with simultaneous high energy and momentum resolution (ELS-LEED) in combination with low energy electron diffraction (SPA-LEED) and tunneling microscopy. Both surfaces contain a double chain of gold atoms per terrace. Although one-dimensional metallicity and plasmon dispersion is observed only along the wires, two-dimensional effects are important, since plasmon dispersion explicitly depends both on the structural motif of the wires and the terrace width. The electron density on each terrace turns out to be modulated, as seen by tunneling spectroscopy (STS). The effective wire width of 7.5\,Å for Si(553)-Au -- 10.2\,Å for Si(775)-Au -- , determined from plasmon dispersion is in good agreement with STS data. Clear evidence for coupling between wires is seen beyond nearest neighbor coupling.
description: 5 pages, 4 figures
Inositol polyphosphate 5-phosphatases, their role in regulation of phosphoinositides involved in intracellular signalling
Creators: name: O'Malley., Cindy Joy
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Six New Millisecond Pulsars from Arecibo Searches of Fermi Gamma-Ray Sources
Creators: name: Cromartie, H. T.
name: Camilo, F.
name: Kerr, M.
name: Deneva, J. S.
name: Ransom, S. M.
name: Ray, P. S.
name: Ferrara, E. C.
name: Michelson, P. F.
name: Wood, K. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We have discovered six radio millisecond pulsars (MSPs) in a search with the Arecibo telescope of 34 unidentified gamma-ray sources from the Fermi Large Area Telescope (LAT) 4-year point source catalog. Among the 34 sources, we also detected two MSPs previously discovered elsewhere. Each source was observed at a center frequency of 327 MHz, typically at three epochs with individual integration times of 15 minutes. The new MSP spin periods range from 1.99 to 4.66 ms. Five of the six pulsars are in interacting compact binaries (period < 8.1 hr), while the sixth is a more typical neutron star-white dwarf binary with an 83-day orbital period. This is a higher proportion of interacting binaries than for equivalent Fermi-LAT searches elsewhere. The reason is that Arecibo's large gain afforded us the opportunity to limit integration times to 15 minutes, which significantly increased our sensitivity to these highly accelerated systems. Seventeen of the remaining 26 gamma-ray sources are still categorized as strong MSP candidates, and will be re-searched.
description: Accepted for publication in ApJ; 8 pages, 3 figures, 5 tables
Fully linear band crossings at high symmetry points in layers: classification and role of spin-orbit coupling and time reversal
Creators: name: Lazić, Nataša
name: Damljanović, Vladimir
name: Damnjanović, Milan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: All of 320 layer groups, distributed into 80 clusters - single/double ordinary/gray groups - are used to complete systematization of linear (in all directions) band crossings and corresponding effective Hamiltonians in high-symmetry Brillouin zone points of layered materials, refining and expanding in literature existing data. Two- and four-dimensional effective Hamiltonians are determined by the allowed (half)integer (co)representations of the same dimension in the crossing point and one- or two-dimensional generic allowed representations. The resulting dispersion types (having isotropic or anisotropic form) are: single cone (with double degenerate crossing point and non-degenerate branches, or 4-fold degenerate crossing point with double degenerate conical branches), poppy-flower (4-fold degenerate crossing point with two pairs of non-degenerate mutually rotated conical branches), and a fortune teller (with nodal lines). Transition to double group, enabling to include spin-orbit interaction, results in various scenarios at high symmetry points: gap closing, gap opening, cone preserving, cone splitting etc. Analogously, analyzing ordinary to gray group transitions, the role of time reversal symmetry is clarified.
description: 26 pages, 3 figures