cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Mass Loss Evolution in the EUV Low Corona from SDO/AIA Data
Creators: name: López, Fernando M.
name: Cremades, Hebe
name: Nuevo, Federico A.
name: Balmaceda, Laura A.
name: Vásquez, Alberto A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We carry out an analysis of the evacuated mass from three coronal dimming regions observed by the {\it Atmospheric Imaging Assembly} (AIA) on board the {\it Solar Dynamics Observatory}. The three events are unambiguously identified with white-light coronal mass ejections (CMEs) associated in turn with surface activity of diverse nature: an impulsive (M-class) flare, a weak (B-class) flare and a filament eruption without a flare. The use of three AIA coronal passbands allows applying a differential emission measure technique to define the dimming regions and identify their evacuated mass through the analysis of the electronic density depletion associated to the eruptions. The temporal evolution of the mass loss from the three dimmings can be approximated by an exponential equation followed by a linear fit. We determine the mass of the associated CMEs from COR2 data. The results show that the evacuated masses from the low corona represent a considerable amount of the mass of the CMEs. We also find that plasma is still being evacuated from the low corona at the time when the CMEs reach the COR2 field of view. The temporal evolution of the angular width of the CMEs, of the dimming regions in the low corona, and of the flux registered by GOES in soft X-rays are all in close relation with the behavior of mass evacuation from the low corona. We discuss the implications of our findings toward a better understanding of the temporal evolution of several parameters associated to the analyzed dimmings and CMEs.
description: Accepted for publication in Solar Physics on 05 October 2016
On isospectral deformations of an inhomogeneous string
Creators: name: Colville, Kale
name: Gomez, Daniel
name: Szmigielski, Jacek
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: In this paper we consider a class of isospectral deformations of the inhomogeneous string boundary value problem. The deformations considered are generalizations of the isospectral deformation that has arisen in connection with the Camassa-Holm equation for the shallow water waves. It is proved that these new isospectral deformations result in evolution equations on the mass density whose form depends on how the string is tied at the endpoints. Moreover, it is shown that the evolution equations in this class linearize on the spectral side and hence can be solved by the inverse spectral method. In particular, the problem involving a mass density given by a discrete finite measure and arbitrary boundary conditions is shown to be solvable by Stieltjes' continued fractions.
description: 33 pages, to appear in Commun. Math. Phys., pdfLaTex + AMS packages
The N/D method with non-perturbative left-hand-cut discontinuity and the $^1S_0$ $NN$ partial wave
Creators: name: Entem, D. R.
name: Oller, J. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this letter we deduce an integral equation that allows to calculate the exact left-hand-cut discontinuity for an uncoupled $S$-wave partial-wave amplitude in potential scattering for a given finite-range potential. The results obtained from the $N/D$ method for the partial-wave amplitude are rigorous, since now the discontinuities along the left-hand cut and right-hand cut are exactly known. This solves the open question with respect to the $N/D$ method and the effect on the final result of the non-perturbative iterative diagrams in the evaluation of $Δ(A)$. A big advantage of the method is that short-range physics (corresponding to integrated out degrees of freedom within low-energy Effective Field Theory) does not contribute to $Δ(A)$ and it manifests through the extra subtractions that are implemented within the method. We show the equivalence of the $N/D$ method and the Lippmann-Schwinger (LS) equation for a nonsingular $^1S_0$ $NN$ potential (Yukawa potential). The equivalence between the $N/D$ method with one extra subtraction and the LS equation renormalized with one counter term or with subtractive renormalization also holds for the singular attractive higher-order ChPT potentials. The $N/D$ method also allows to evaluate partial-wave amplitudes with a higher number of extra subtractions, that we fix in terms of shape parameters within the effective range expansion. The result at NNLO shows that the $^1S_0$ phase shifts might be accurately described once the electromagnetic and charge symmetry breaking terms are included. Our present results can be extended to higher partial waves as well as to coupled channel scattering.
description: 7 pages, 1 table and 7 figures
New prospects for observing and cataloguing exoplanets in well detached binaries
Creators: name: Schwarz, R.
name: Funk, B.
name: Zechner, R.
name: Bazso, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: This paper is devoted to study the circumstances favourable to detect circumstellar and circumbinary planets in well detached binary-star-systems using eclipse timing variations (ETVs). We investigated the dynamics of well detached binary star systems with a star separation from 0.5 to 3~AU, to determine the probability of the detection of such variations with ground based telescopes and space telescopes (like former missions CoRoT and Kepler and future space missions Plato, Tess and Cheops). For the chosen star separations both dynamical configurations (circumstellar and circumbinary) may be observable. We performed numerical simulations by using the full three-body problem as dynamical model. The dynamical stability and the ETVs are investigated by computing ETV maps for different masses of the secondary star and the exoplanet (Earth, Neptune and Jupiter size). In addition we changed the planet's and binary's eccentricities. We conclude that many amplitudes of ETVs are large enough to detect exoplanets in binary star systems. As an application, we prepared statistics of the catalogue of exoplanets in binary star systems which we introduce in this article and compared the statistics with our parameter-space which we used for our calculations. In addition to these statistics of the catalogue we enlarged them by the investigation of well detached binary star systems from several catalogues and discussed the possibility of further candidates.
description: 14 pages, 11 figures
Modulated heat pulse propagation and partial transport barriers in chaotic magnetic fields
Creators: name: del-Castillo-Negrete, D.
name: Blazevski, D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Direct numerical simulations of the time dependent parallel heat transport equation modeling heat pulses driven by power modulation in 3-dimensional chaotic magnetic fields are presented. The numerical method is based on the Fourier formulation of a Lagrangian-Green's function method that provides an accurate and efficient technique for the solution of the parallel heat transport equation in the presence of harmonic power modulation. The numerical results presented provide conclusive evidence that even in the absence of magnetic flux surfaces, chaotic magnetic field configurations with intermediate levels of stochasticity exhibit transport barriers to modulated heat pulse propagation. In particular, high-order islands and remnants of destroyed flux surfaces (Cantori) act as partial barriers that slow down or even stop the propagation of heat waves at places where the magnetic field connection length exhibits a strong gradient. Results on modulated heat pulse propagation in fully stochastic fields and across magnetic islands are also presented. In qualitative agreement with recent experiments in LHD and DIII-D, it is shown that the elliptic (O) and hyperbolic (X) points of magnetic islands have a direct impact on the spatio-temporal dependence of the amplitude of modulated heat pulses.
Detection-dependent six-photon NOON state interference
Creators: name: Jin, Rui-Bo
name: Fujiwara, Mikio
name: Shimizu, Ryosuke
name: Collins, Robert J.
name: Buller, Gerald S.
name: Yamashita, Taro
name: Miki, Shigehito
name: Terai, Hirotaka
name: Takeoka, Masahiro
name: Sasaki, Masahide
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: NOON state interference (NOON-SI) is a powerful tool to improve the phase sensing precision, and can play an important role in quantum sensing and quantum imaging. However, most of the previous NOON-SI experiments only investigated the center part of the interference pattern, while the full range of the NOON-SI pattern has not yet been well explored.In this Letter, we experimentally and theoretically demonstrate up to six-photon NOON-SI and study the properties of the interference patterns over the full range.The multi-photons were generated at a wavelength of 1584 nm from a PPKTP crystal in a parametric down conversion process.It was found that the shape, the coherence time and the visibility of the interference patterns were strongly dependent on the detection schemes.This experiment can be used for applications which are based on the envelope of the NOON-SI pattern, such as quantum spectroscopy and quantum metrology.
description: 5 pages, 3 figures
Estruturas de Concreto Armado IBRACON Vol1 - B01 - Histórico e Aplicações
Creators: name: Da Costa Pantoja, João
Publisher: name: Zenodo
Year: 2023

description: O mais completo, importante e atual livro brasileiro de projeto de estruturas de concreto, resultante de mais uma profícua parceria da ABECE com o IBRACON. Contém referências a normas, programas, algoritmos, exemplos e procedimentos consagrados no país. Apresenta os princípios, conceitos e exemplos necessários à concepção e detalhamento de um projeto estrutural para edificações em concreto armado e protendido no Brasil. É aderente, principalmente, à norma brasileira ABNT NBR 6118 em sua
 última versão de 2022, ainda em discussão, e a todas outras, nacionais e internacionais, correlatas e complementares.
 Prof Paulo Helene
Superconductivity and hybrid soft modes in TiSe$_2$
Creators: name: Maschek, M.
name: Rosenkranz, S.
name: Hott, R.
name: Heid, R.
name: Zocco, D.
name: Said, A. H.
name: Alatas, A.
name: Karapetrov, G.
name: Zhu, Shan
name: van Wezel, Jasper
name: Weber, F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The competition between superconductivity and other ground states of solids is one of the challenging topics in condensed matter physics. Apart from high-temperature superconductors [1,2] this interplay also plays a central role in the layered transition-metal dichalcogenides, where superconductivity is stabilized by suppressing charge-density-wave order to zero temperature by intercalation [3] or applied pressure [4-7]. 1T-TiSe$_2$ forms a prime example, featuring superconducting domes on intercalation as well as under applied pressure. Here, we present high energy-resolution inelastic x-ray scattering measurements of the CDW soft phonon mode in intercalated Cu$_x$TiSe$_2$ and pressurized 1T-TiSe$_2$ along with detailed ab-initio calculations for the lattice dynamical properties and phonon-mediated superconductivity. We find that the intercalation-induced superconductivity can be explained by a solely phonon-mediated pairing mechanism, while this is not possible for the superconducting phase under pressure. We argue that a hybridization of phonon and exciton modes in the pairing mechanism is necessary to explain the full observed temperature-pressure-intercalation phase diagram. These results indicate that 1T-TiSe$_2$ under pressure is close to the elusive state of the excitonic insulator.
Fermion-antifermion scattering via boson exchange in a trapped ion
Creators: name: Zhang, Xiang
name: Zhang, Kuan
name: Shen, Yangchao
name: Zhang, Jingning
name: Yung, Man-Hong
name: Casanova, Jorge
name: Pedernales, Julen S.
name: Lamata, Lucas
name: Solano, Enrique
name: Kim, Kihwan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum field theories describe a wide variety of fundamental phenomena in physics. However, their study often involves cumbersome numerical simulations. Quantum simulators, on the other hand, may outperform classical computational capacities due to their potential scalability. Here, we report an experimental realization of a quantum simulation of fermion-antifermion scattering mediated by bosonic modes, using a multilevel trapped ion, which is a simplified model of fermion scattering in both perturbative and nonperturbative quantum electrodynamics. The simulated model exhibits prototypical features in quantum field theory including particle pair creation and annihilation, as well as self-energy interactions. These are experimentally observed by manipulating four internal levels of a $^{171}\mathrm{Yb}^{+}$ trapped ion, where we encode the fermionic modes, and two motional degrees of freedom that simulate the bosonic modes. Our experiment establishes an avenue towards the efficient implementation of fermionic and bosonic quantum field modes, which may prove useful in scalable studies of quantum field theories in perturbative and nonperturbative regimes.
description: 12 pages, 3 figures
Experimental demonstration of phase bistability in a broad area optical oscillator with injected signal
Creators: name: Martínez-Lorente, R.
name: Esteban-Martín, A.
name: Rolán, E.
name: Staliunas, K.
name: de Valcárcel, G. J.
name: Silva, F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We demonstrate experimentally that a broad area laser-like optical oscillator (a nondegenerate photorefractive oscillator) with structured injected signal displays two-phase patterns. The technique (G. J. de Valcárcel and K. Staliunas, Phys. Rev. Lett. (105), 054101 (2010)) consists in spatially modulating the injection, so that its phase alternates periodically between two opposite values, i.e. differing by pi
Ground-state and magnetocaloric properties of a coupled spin-electron double-tetrahedral chain (exact study at the half filling)
Creators: name: Galisova, Lucia
name: Jakubczyk, Dorota
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Ground-state and magnetocaloric properties of a double-tetrahedral chain, in which nodal lattice sites occupied by the localized Ising spins regularly alternate with triangular clusters half filled with mobile electrons, are exactly investigated by using the transfer-matrix method in combination with the construction of the $N$th tensor power of the discrete Fourier transformation. It is shown that the ground state of the model is formed by two non-chiral phases with the zero residual entropy and two chiral phases with the finite residual entropy $S = Nk_{\rm B}\ln 2$. Depending on the character of the exchange interaction between the localized Ising spins and mobile electrons, one or three magnetization plateaus can be observed in the magnetization process. Their heights basically depend on the values of Landé $g$-factors of the Ising spins and mobile electrons. It is also evidenced that the system exhibits both the conventional and inverse magnetocaloric effect depending on values of the applied magnetic field and temperature.
description: 16 pages, 9 figures
Design of artificial genetic regulatory networks with multiple delayed adaptive responses
Creators: name: Kaluza, Pablo
name: Inoue, Masayo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Molecular Networks (q-bio.MN)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Genetic regulatory networks with adaptive responses are widely studied in biology. Usually, models consisting only of a few nodes have been considered. They present one input receptor for activation and one output node where the adaptive response is computed. In this work, we design genetic regulatory networks with many receptors and many output nodes able to produce delayed adaptive responses. This design is performed by using an evolutionary algorithm of mutations and selections that minimizes an error function defined by the adaptive response in signal shapes. We present several examples of network constructions with a predefined required set of adaptive delayed responses. We show that an output node can have different kinds of responses as a function of the activated receptor. Additionally, complex network structures are presented since processing nodes can be involved in several input-output pathways.
Electronic quantum optics beyond the integer quantum Hall effect
Creators: name: Ferraro, D.
name: Jonckheere, T.
name: Rech, J.
name: Martin, T.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The analog of two seminal quantum optics experiments are considered in a condensed matter setting with single electron sources injecting electronic wave packets on edge states coupled through a quantum point contact. When only one electron is injected, the measurement of noise correlations at the output of the quantum point contact corresponds to the Hanbury-Brown and Twiss setup. When two electrons are injected on opposite edges, the equivalent of the Hong-Ou-Mandel collision is achieved, exhibiting a dip as in the coincidence measurements of quantum optics. The Landauer-Buttiker scattering theory is used to first review these phenomena in the integer quantum Hall effect, next, to focus on two more exotic systems: edge states of two dimensional topological insulators, where new physics emerges from time reversal symmetry and three electron collisions can be achieved; and edges states of a hybrid Hall/superconducting device, which allow to perform electron quantum optics experiments with Bogoliubov quasiparticles.
description: 13 pages, 10 figures, invited contribution for a focus issue on "Single-electron control in solid-state devices"
Neutron lifetime measurements and effective spectral cleaning with an ultracold neutron trap using a vertical Halbach octupole permanent magnet array
Creators: name: Leung, K. K. H.
name: Geltenbort, P.
name: Ivanov, S.
name: Rosenau, F.
name: Zimmer, O.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Ultracold neutron (UCN) storage measurements were made in a trap constructed from a 1.3 T Halbach Octupole PErmanent (HOPE) magnet array aligned vertically, using the TES-port of the PF2 source at the Institut Laue-Langevin. A mechanical UCN valve at the bottom of the trap was used for filling and emptying. This valve was covered with Fomblin grease to induce non-specular reflections and was used in combination with a movable polyethylene UCN remover inserted from the top for cleaning of above-threshold UCNs. Loss due to UCN depolarization was suppressed with a minimum 2 mT bias field. Without using the UCN remover, a total storage time constant of $(712 \pm 19)$ s was observed; with the remover inserted for 80 s and used at either 80 cm or 65 cm from the bottom of the trap, time constants of $(824 \pm 32)$ s and $(835 \pm 36)$ s were observed. Combining the latter two values, a neutron lifetime of $τ_{\rm n} = (887 \pm 39)$ s is extracted after primarily correcting for losses at the UCN valve. The time constants of the UCN population during cleaning were observed and compared to calculations based on UCN kinetic theory as well as Monte-Carlo studies. These calculations are used to predict above-threshold populations of $\sim 5\%$, $\sim 0.5\%$ and $\sim 10^{-12}\%$ remaining after cleaning in the no remover, 80~cm remover and 65~cm remover measurements. Thus, by using a non-specular reflector covering the entire bottom of the trap and a remover at the top of the trap, we have established an effective cleaning procedure for removing a major systematic effect in high-precision $τ_{\rm n}$ experiments with magnetically stored UCNs.
description: To be submitted to Physical Review C
Existence of energy-variational solutions to hyperbolic conservation laws
Creators: name: Eiter, Thomas
name: Lasarzik, Robert
Publisher: name: Weierstrass Institute
Year: 2022
Subjects: subject: Existence
subject: generalized solutions
subject: conservation laws
subject: time discretization
subject: weak-strong
subject: uniqueness
subject: Euler equations
subject: 35L45
subject: 35L65
subject: 35A01
subject: 35A15
subject: 35D99
subject: 35Q31
subject: 76B03
subject: 76N10

description: We introduce the concept of energy-variational solutions for hyperbolic conservation laws. Intrinsically, these energy-variational solutions fulfill the weak-strong uniqueness principle and the semi-flow property, and the set of solutions is convex and weakly-star closed. The existence of energy-variational solutions is proven via a suitable time-discretization scheme under certain assumptions. This general result yields existence of energy-variational solutions to the magnetohydrodynamical equations for ideal incompressible fluids and to the Euler equations in both the incompressible and the compressible case. Moreover, we show that energy-variational solutions to the Euler equations coincide with dissipative weak solutions.
Design Principles for Data Analysis
Creators: name: McGowan, Lucy D’Agostino
name: Peng, Roger D.
name: Hicks, Stephanie C.
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biotechnology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Science Policy
subject: Hematology

description: The data revolution has led to an increased interest in the practice of data analysis. While much has been written about statistical thinking, a complementary form of thinking that appears in the practice of data analysis is design thinking—the problem-solving process to understand the people for whom a solution is being designed. For a given problem, there can be significant or subtle differences in how a data analyst (or producer of a data analysis) constructs, creates, or designs a data analysis, including differences in the choice of methods, tooling, and workflow. These choices can affect the data analysis products themselves and the experience of the consumer of the data analysis. Therefore, the role of a producer can be thought of as designing the data analysis with a set of design principles. Here, we introduce design principles for data analysis and describe how they can be mapped to data analyses in a quantitative and informative manner. We also provide data showing variation of principles within and between producers of data analyses. Our work suggests a formal mechanism to describe data analyses based on design principles. These results provide guidance for future work in characterizing the data analytic process. Supplementary materials for this article are available online.
A model for distortions of polarisation-angle curves in radio pulsars
Creators: name: Dyks, J.
name: Serylak, M.
name: Oslowski, S.
name: Saha, L.
name: Guillemot, L.
name: Cognard, I.
name: Rudak, B.
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: Some radio pulsar profiles (in particular those of millisecond pulsars contain wide emission structures which cover large intervals of pulse phase. Local distortions of an average curve of polarisation angle (PA) can be identified in such profiles, and they are often found to be associated with absorption features or narrow emission components. The features may be interpreted as a convolution of a lateral profile of an emitter with a microscopic radiation pattern of a non-negligible angular extent. We study a model which assumes that such an extended microbeam of the X-mode curvature radiation is spreading the radiation polarised at a fixed position angle within an interval of pulse phase. The model is capable of interpreting the strongly dissimilar polarisation of double notches in PSR B1821-24A (for which we present new polarisation data from the Nancay Radio Telescope) and PSR J0437-4715. It also explains a step-like change in PA observed at the bifurcated trailing component in the profile of J0437-4715. A generic form of the modelled PA distortion is a zigzag-shaped wiggle, which in the presence of the second polarisation mode (O mode) can be magnified or transformed into a W- or U-shaped deflection of a total net PA. The model's efficiency in interpreting dissimilar polarisation effects provides further credence to the stream-based (fan-beam) geometry of pulsar emission. It also suggests that the microbeam width may not always be assumed negligible in comparison with the angular scale of emissivity gradients in the emission region.
description: 14 pages, 16 figures, accepted for publication in Astronomy and Astrophysics
New insights into the photochromic mechanism in oxygen-containing yttrium hydride thin films: an optical perspective
Creators: name: Montero, J.
name: Martinsen, F. A.
name: Karazhanov, S. Zh.
name: Hauback, B. C.
name: Marstein, E. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Oxygen-containing yttrium hydride thin films exhibit a photochromic behavior: transparent thin films switch from a transparent state to a photodarkened state after being illuminated with UV or blue light. This feature has attracted much attention in recent years due to its potential applications in smart fenestration or in any device in which a response to intense light radiation is needed. However, the process responsible for the reversible change of the optical properties upon illumination is still not well understood. The objective of the present work is to shed some light on the photochromic mechanism by using an optical approach. On this basis, the optical properties of oxygen-containing yttrium hydride thin films have been studied by optical spectrophotometry and ellipsometry before (transparent state) and after UV illumination (dark state). According to the observed results, the photochromic optical change of the films can be explained quantitatively by the gradual growth, under illumination, of metallic phases within the initial wide-band gap semiconducting lattice.
description: 5 pages 5 figures
A cubic scaling algorithm for excited states calculations in particle-particle random phase approximation
Creators: name: Lu, Jianfeng
name: Yang, Haizhao
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The particle-particle random phase approximation (pp-RPA) has been shown to be capable of describing double, Rydberg, and charge transfer excitations, for which the conventional time-dependent density functional theory (TDDFT) might not be suitable. It is thus desirable to reduce the computational cost of pp-RPA so that it can be efficiently applied to larger molecules and even solids. This paper introduces an $O(N^3)$ algorithm, where $N$ is the number of orbitals, based on an interpolative separable density fitting technique and the Jacobi-Davidson eigensolver to calculate a few low-lying excitations in the pp-RPA framework. The size of the pp-RPA matrix can also be reduced by keeping only a small portion of orbitals with orbital energy close to the Fermi energy. This reduced system leads to a smaller prefactor of the cubic scaling algorithm, while keeping the accuracy for the low-lying excitation energies.
Shear piezoelectricity in poly(vinylidenefluoride-co-trifluoroethylene): full piezotensor coefficients by molecular modeling, biaxial transverse response, and use in suspended energy-harvesting nanostructures
Creators: name: Persano, Luana
name: Catellani, Alessandra
name: Dagdeviren, Canan
name: Ma, Yinji
name: Guo, Xiaogang
name: Huang, Yonggang
name: Calzolari, Arrigo
name: Pisignano, Dario
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The intrinsic flexible character of polymeric materials also causes remarkable strain deformations along directions perpendicular to the applied stress. Here the biaxial response in the shear piezoelectricity of polyvinylidenefluoride copolymers is analyzed and their full piezoelectric tensors are provided. The microscopic shear is exploited in single suspended nanowires bent by localized loading to couple flexural deformation and transverse piezoelectric response.
description: 36 pages, 10 figures, 2 tables, 49 references, Advanced Materials, 2016
A path towards understanding the rotation-activity relation of M dwarfs with K2 mission, X-ray and UV data
Creators: name: Stelzer, B.
name: Damasso, M.
name: Scholz, A.
name: Matt, S. P.
name: --
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We study the relation between stellar rotation and magnetic activity for a sample of 134 bright, nearby M dwarfs observed in the Kepler Two-Wheel (K2) mission during campaigns C0 to C4. The K2 lightcurves yield photometrically derived rotation periods for 97 stars (79 of which without previous period measurement), as well as various measures for activity related to cool spots and flares. We find a clear difference between fast and slow rotators with a dividing line at a period of ~10d at which the activity level changes abruptly. All photometric diagnostics of activity (spot cycle amplitude, flare peak amplitude and residual variability after subtraction of spot and flare variations) display the same dichotomy, pointing to a quick transition between a high-activity mode for fast rotators and a low-activity mode for slow rotators. This unexplained behavior is reminiscent of a dynamo mode-change seen in numerical simulations that separates a dipolar from a multipolar regime. A substantial number of the fast rotators are visual binaries. A tentative explanation is accelerated disk evolution in binaries leading to higher initial rotation rates on the main-sequence and associated longer spin-down and activity lifetimes. We combine the K2 rotation periods with archival X-ray and UV data. X-ray, FUV and NUV detections are found for 26, 41, and 11 stars from our sample, respectively. Separating the fast from the slow rotators, we determine for the first time the X-ray saturation level separately for early- and for mid-M stars.
description: Accepted for publication in MNRAS (22 pages, 15 figures)
ALMA band 8 continuum emission from Orion Source I
Creators: name: Hirota, Tomoya
name: Machida, Masahiro N.
name: Matsushita, Yuko
name: Motogi, Kazuhito
name: Matsumoto, Naoko
name: Kim, Mi Kyoung
name: Burns, Ross A.
name: Honma, Mareki
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We have measured continuum flux densities of a high-mass protostar candidate, a radio source I in the Orion KL region (Orion Source I) using the Atacama Large Millimeter/Submillimeter Array (ALMA) at band 8 with an angular resolution of 0.1". The continuum emission at 430, 460, and 490 GHz associated with Source I shows an elongated structure along the northwest-southeast direction perpendicular to the so-called low-velocity bipolar outflow. The deconvolved size of the continuum source, 90 au times 20 au, is consistent with those reported previously at other millimeter/submillimeter wavelength. The flux density can be well fitted to the optically thick black-body spectral energy distribution (SED), and the brightness temperature is evaluated to be 700-800 K. It is much lower than that in the case of proton-electron or H- free-free radiations. Our data are consistent with the latest ALMA results by Plambeck & Wright (2016), in which the continuum emission have been proposed to arise from the edge-on circumstellar disk via thermal dust emission, unless the continuum source consists of an unresolved structure with the smaller beam filling factor.
description: 5 pages, 2 figures, accepted for publication in the The Astrophysical Journal
XSHOOTER spectroscopy of the enigmatic planetary nebula Lin49 in the Small Magellanic Cloud
Creators: name: Otsuka, Masaaki
name: Kemper, F.
name: Leal-Ferreira, M. L.
name: Aleman, I.
name: Bernard-Salas, J.
name: Cami, J.
name: Ochsendorf, B.
name: Peeters, E.
name: Scicluna, P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We performed a detailed spectroscopic analysis of the fullerene C60-containing planetary nebula (PN) Lin49 in the Small Magellanic Cloud using XSHOOTER at the ESO VLT and the Spitzer/IRS instruments. We derived nebular abundances for nine elements. We used TLUSTY to derive photospheric parameters for the central star. Lin49 is C-rich and metal-deficient PN (Z~0.0006). The nebular abundances are in good agreement with Asymptotic Giant Branch nucleosynthesis models for stars with initial mass 1.25 Msun and metallicity Z = 0.001. Using the TLUSTY synthetic spectrum of the central star to define the heating and ionising source, we constructed the photoionisation model with CLOUDY that matches the observed spectral energy distribution (SED) and the line fluxes in the UV to far-IR wavelength ranges simultaneously. We could not fit the ~1-5 um SED using a model with 0.005-0.1 um-sized graphite grains and a constant hydrogen density shell owing to the prominent near-IR excess, while at other wavelengths the model fits the observed values reasonably well. We argue that the near-IR excess might indicate either (1) the presence of very small particles in the form of small carbon clusters, small graphite sheets, or fullerene precursors, or (2) the presence of a high-density structure surrounding the central star. We found that SMC C60 PNe show a near-IR excess component to lesser or greater degree. This suggests that these C60 PNe might maintain a structure nearby their central star.
description: 24 pages, 17 figures, 17 tables, Accepted for publication by MNRAS
Engineering chiral light--matter interaction in photonic crystal waveguides with slow light
Creators: name: Mahmoodian, Sahand
name: Prindal-Nielsen, Kasper
name: Söllner, Immo
name: Stobbe, Søren
name: Lodahl, Peter
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We design photonic crystal waveguides with efficient chiral light--matter interfaces that can be integrated with solid-state quantum emitters. By using glide-plane-symmetric waveguides, we show that chiral light-matter interaction can exist even in the presence of slow light with slow-down factors of up to $100$ and therefore the light--matter interaction exhibits both strong Purcell enhancement and chirality. This allows for near-unity directional $β$-factors for a range of emitter positions and frequencies. Additionally, we design an efficient mode adapter to couple light from a standard nanobeam waveguide to the glide-plane symmetric photonic crystal waveguide. Our work sets the stage for performing future experiments on a solid-state platform.
Temperature scaling of effective polaron mobility in energetically disordered media
Creators: name: Seki, Kazuhiko
name: Wojcik, Mariusz
Publisher: name: arXiv
Year: 2016
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study effective mobility in 2 dimensional (2D) and 3 dimensional (3D) systems, where hopping transitions of carriers are described by the Marcus equation under a Gaussian density of states in the dilute limit. Using an effective medium approximation (EMA), we determined the coefficient $C_d$ for the effective mobility expressed by $μ_{\rm eff}\propto\exp\left[-λ/\left(4 k_{\rm B} T\right)- C_dσ^2/\left(k_{\rm B} T\right)^2 \right]/\left[\sqrtλ (k_{\rm B} T)^{3/2}\right]$, where $λ$ is the reorganization energy, $σ$ is the standard deviation of the Gaussian density of states, and $k_{\rm B} T$ takes its usual meaning. We found $C_d=1/2$ for both 2D and 3D. While various estimates of the coefficient $C_d$ for 3D systems are available in the literature, we provide for the first time the expected $C_d$ value for a 2D system. By means of kinetic Monte-Carlo simulations, we show that the effective mobility is well described by the equation shown above under certain conditions on $λ$. We also give examples of analysis of experimental data for 2D and 3D systems based on our theoretical results.
description: 4 Figs
A new infinite family of non-abelian strongly real Beauville $p$-groups for every odd prime $p$
Creators: name: Fairbairn, Ben
Publisher: name: arXiv
Year: 2016
Subjects: subject: Group Theory (math.GR)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: We prove that there exist infinitely many a non-abelian strongly real Beauville $p$-group for every prime $p$. Previously only finitely many in the case $p=2$ have been constructed.
description: 5 pages, all comments welcome!
On the differentiability of solutions of stochastic evolution equations with respect to their initial values
Creators: name: Andersson, Adam
name: Jentzen, Arnulf
name: Kurniawan, Ryan
name: Welti, Timo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this article we study the differentiability of solutions of parabolic semilinear stochastic evolution equations (SEEs) with respect to their initial values. We prove that if the nonlinear drift coefficients and the nonlinear diffusion coefficients of the considered SEEs are $n$-times continuously Fréchet differentiable, then the solutions of the considered SEEs are also $n$-times continuously Fréchet differentiable with respect to their initial values. Moreover, a key contribution of this work is to establish suitable enhanced regularity properties of the derivative processes of the considered SEE in the sense that the dominating linear operator appearing in the SEE smoothes the higher order derivative processes.
Hydrodynamic Modeling of Accretion Impacts in Classical T Tauri Stars: Radiative Heating of the Pre-shock Plasma
Creators: name: Costa, G.
name: Orlando, S.
name: Peres, G.
name: Argiroffi, C.
name: Bonito, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. It is generally accepted that, in Classical T Tauri Stars, the plasma from the circumstellar disc accretes onto the stellar surface with free fall velocity, and the impact generates a shock. The impact region is expected to contribute to emission in different spectral bands; many studies have confirmed that the X-rays arise from the post-shock plasma but, otherwise, there are no studies in the literature investigating the origin of the observed UV emission which is apparently correlated to accretion. Aims. We investigated the effect of radiative heating of the infalling material by the post-shock plasma at the base of the accretion stream with the aim to identify in which region a significant part of the UV emission originates. Methods. We developed a 1D hydrodynamic model describing the impact of an accretion stream onto the stellar surface; the model takes into account the gravity, the radiative cooling of an optically thin plasma, the thermal conduction, and the heating due to absorption of X-ray radiation. The latter term represents the heating of the infalling plasma due to the absorption of X-rays emitted from the post-shock region. Results. We found that the radiative heating of the pre-shock plasma plays a non-negligible role in the accretion phenomenon. In particular, the dense and cold plasma of the pre-shock accretion column is gradually heated up to few $10^5$\;K due to irradiation of X-rays arising from the shocked plasma at the impact region. This heating mechanism does not affect significantly the dynamics of the post-shock plasma. On the other hand, a region of radiatively heated gas (that we consider a precursor) forms in the unshocked accretion column and contributes significantly to UV emission. Our model naturally reproduces the luminosity of UV emission lines correlated to accretion and shows that most of the UV emission originates from the precursor.
Metal-Mott insulator interfaces
Creators: name: Lee, Juho
name: Yee, Chuck-Hou
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Motivated by the direct observation of electronic phase separation in first-order Mott transitions, we model the interface between the thermodynamically coexisting metal and Mott insulator. We show how to model the required slab geometry and extract the electronic spectra. We construct an effective Landau free energy and compute the variation of its parameters across the phase diagram. Finally, using a linear mixture of the density and double-occupancy, we identify a natural Ising order parameter which unifies the treatment of the bandwidth and filling controlled Mott transitions.
description: 5 pages, 5 figures, 2 pages supplementary
Strong electron-phonon coupling in the sigma band of graphene
Creators: name: Mazzola, Federico
name: Frederiksen, Thomas
name: Balasubramanian, Thiagarajan
name: Hofmann, Philip
name: Hellsing, Bo
name: Wells, Justin W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: First-principles studies of the electron-phonon coupling in graphene predict a high coupling strength for the $σ$ band with $λ$ values of up to 0.9. Near the top of the $σ$ band, $λ$ is found to be $\approx 0.7$. This value is consistent with the recently observed kinks in the $σ$ band dispersion by angle-resolved photoemission. While the photoemission intensity from the $σ$ band is strongly influenced by matrix elements due to sub-lattice interference, these effects differ significantly for data taken in the first and neighboring Brillouin zones. This can be exploited to disentangle the influence of matrix elements and electron-phonon coupling. A rigorous analysis of the experimentally determined complex self-energy using Kramers-Kronig transformations further supports the assignment of the observed kinks to strong electron-phonon coupling and yields a coupling constant of $0.6(1)$, in excellent agreement with the calculations.
description: 11 pages, 3 figures
OH+ and H2O+ absorption toward PKS1830-211
Creators: name: Muller, S.
name: M"uller, H. S. P.
name: Black, J. H.
name: Beelen, A.
name: Combes, F.
name: Curran, S.
name: Gerin, M.
name: Guelin, M.
name: Henkel, C.
name: Martin, S.
name: Aalto, S.
name: Falgarone, E.
name: Menten, K. M.
name: Schilke, P.
name: Wiklind, T.
name: Zwaan, M. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We report the detection of OH+ and H2O+ in the z=0.89 absorber toward the lensed quasar PKS1830-211. The abundance ratio of OH+ and H2O+ is used to quantify the molecular hydrogen fraction (fH2) and the cosmic-ray ionization rate of atomic hydrogen (zH) along two lines of sight, located at ~2 kpc and ~4 kpc to either side of the absorber's center. The molecular fraction decreases outwards, from ~0.04 to ~0.02, comparable to values measured in the Milky Way at similar galactocentric radii. For zH, we find values of ~2x10^-14 s^-1 and ~3x10^-15 s^-1, respectively, which are slightly higher than in the Milky Way at comparable galactocentric radii, possibly due to a higher average star formation activity in the z=0.89 absorber. The ALMA observations of OH+, H2O+, and other hydrides toward PKS1830-211 reveal the multi-phase composition of the absorbing gas. Taking the column density ratios along the southwest and northeast lines of sight as a proxy of molecular fraction, we classify the species ArH+, OH+, H2Cl+, H2O+, CH, and HF as tracing gases increasingly more molecular. Incidentally, our data allow us to improve the accuracy of H2O+ rest frequencies and thus refine the spectroscopic parameters.
description: Accepted for publication in A&A
Spectral Energy Distribution Mapping of Two Elliptical Galaxies on sub-kpc scales
Creators: name: Amblard, Alexandre
name: Temi, Pasquale
name: Gaspari, Massimo
name: Brighenti, Fabrizio
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We use high-resolution Herschel-PACS data of 2 nearby elliptical galaxies, IC1459 & NGC2768 to characterize their dust and stellar content. IC1459 & NGC2768 have an unusually large amount of dust for elliptical galaxies (1-3 x 10^5 Msun), this dust is also not distributed along the stellar content. Using data from GALEX (ultraviolet) to PACS (far-infrared), we analyze the spectral energy distribution (SED) of these galaxies with CIGALEMC as a function of the projected position, binning images in 7.2" pixels. From this analysis, we derive maps of SED parameters, such as the metallicity, the stellar mass, the fraction of young star and the dust mass. The larger amount of dust in FIR maps seems related in our model to a larger fraction of young stars which can reach up to 4% in the dustier area. The young stellar population is fitted as a recent (~ 0.5 Gyr) short burst of star formation for both galaxies. The metallicities, which are fairly large at the center of both galaxies, decrease with the radial distance with fairly steep gradient for elliptical galaxies.
description: 14 pages, 26 figures, to be published in ApJ
Speed limits in Liouville space for open quantum systems
Creators: name: Uzdin, Raam
name: Kosloff, Ronnie
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: One of the defining properties of an open quantum system is the variation of its purity in time. We derive speed limits on the rate of purity change for systems coupled to a Markovian environment. Our speed limits are based on Liouville space where density matrices are represented as vectors. This approach leads to speed limits that are always tighter compared to their parallel speed limits in Hilbert space. These bounds depend solely on the generators of the nonunitary dynamics and are independent of the particular states of the systems. Thus, they are perfectly suited to investigate dephasing, thermalization, and decorrelation processes of arbitrary states. We show that our speed limits can be attained and are therefore tight. As an application of our results we study correlation loss, and the speed of classical and quantum correlation erasure in multi-particle system.
description: This paper supersedes arXiv:1408.1227, with differing authorship. A proof is given to a conjecture made in arXiv:1408.1227 and new significant applications were introduced