cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
State-of-the-art of beyond mean field theories with nuclear density functionals
Creators: name: Egido, J. Luis
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We present an overview of beyond mean field theories (BMFT) based on the generator coordinate method (GCM) and the recovery of symmetries used in nuclear physics with effective forces. After a reminder of the Hartree-Fock-Bogoliubov (HFB) theory a discussion of the shortcomings of any mean field approximation (MFA) is presented. The recovery of the symmetries spontaneously broken in the HFB approach, in particular the angular momentum, is necessary, among others, to describe excited states and transitions. Particle number projection is needed to guarantee the right number of protons and neutrons. Furthermore a projection before the variation prevents the pairing collapse in the weak pairing regime. The lack of fluctuations around the average values of the MFA is a shortcoming of this approach. To build in correlations in BMFT one selects the relevant degrees of freedom: quadrupole, octupole and the pairing vibrations as well as the single particle ones. In the GCM the operators representing these degrees of freedom are used as coordinates to generate a collective subspace. The highly correlated GCM wave function is finally written as a linear combination of a projected basis of this space. The variation of the coefficients of the linear combination leads to the Hill-Wheeler equation. We discuss the classical beta and gamma vibrations by considering the quadrupole operators as coordinates. We present pairing fluctuations by considering the pairing gaps as generator coordinates. Lastly the explicit consideration of the time reversal symmetry breaking in the HFB wave function by the cranking procedure allows the alignment of nucleon pairs opening a new dimension in the BMFT calculations. Abundant calculations with the Gogny force illustrate the state-of-the-art of BMFTs with density functionals. We conclude with a thorough discussion on the potential poles of the theory.
description: To be published in Physica Scripta as an invited comment in a focus issue to celebrate the 40-year anniversary of the 1975 Nobel Prize to Aage Niels Bohr, Ben Roy Mottelson and Leo James Rainwater
Search for 511 keV Emission in Satellite Galaxies of the Milky Way with INTEGRAL/SPI
Creators: name: Siegert, Thomas
name: Diehl, Roland
name: Vincent, Aaron C.
name: Guglielmetti, Fabrizia
name: Krause, Martin G. H.
name: Boehm, Celine
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The positron annihilation gamma-ray signal in the Milky Way (MW) shows a puzzling morphology: a very bright bulge and a very low surface-brightness disk. A coherent explanation of the positron origin, propagation through the Galaxy and subsequent annihilation in the interstellar medium has not yet been found. Tentative explanations involve positrons from radioactivity, X-ray binaries, and dark matter (DM). Dwarf satellite galaxies (DSGs) are believed to be DM-dominated and hence promising candidates in the search for 511 keV emission as a result of DM annihilation into electron-positron pairs. The goal of this study is to constrain possible 511 keV gamma-ray signals from 39 DSGs of the MW and to test the annihilating DM scenario. We use the spectrometer SPI on INTEGRAL to extract individual spectra for the studied objects. As the diffuse galactic emission dominates the signal, the large scale morphology of the MW has been modelled accordingly and was included in a maximum likelihood analysis. Alternatively, a distance-weighted stacked spectrum has been determined. Only Reticulum II (Ret II) shows a 3.1 sigma signal. Five other sources show tentative 2 sigma signals. The mass-to-511-keV-luminosity-ratio shows a marginal trend towards higher values for intrinsically brighter objects, opposite to the V band mass-to-light-ratio, which is generally used to uncover DM in DSGs. All derived flux values are above the level implied by a DM interpretation of the MW bulge signal. The signal from Ret II is unlikely to be related to a DM origin alone, otherwise, the MW bulge would be about 100 times brighter than what is seen. Ret II is exceptional considering the DSG sample, and rather points to enhanced recent star formation activity, if its origins are similar to processes in the MW. Understanding this emission may provide further clues regarding the origin of the annihilation emission in the MW.
description: 7 pages, 3 figures, 1 table, accepted by A&A
Extension, Torque and Supercoiling in Single, Stretched and Twisted DNA Molecules
Creators: name: Lam, Pui-Man
name: Zhen, Yi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We reinvestigate the model originally studied by Neukirch and Marko that describes the extension, torque and supercoiling in single, stretched and twisted DNA molecules, which consists of a mixture of extended and supercoiled state, using now a more accurate form of the free energy for the untwisted but stretched DNA. The original model uses an approximate form of this free energy and the agreement with experiment is only qualitative. We find that this more accurate free energy significantly improves the results, bring them into quantitative agreement with experiment, throughout the entire force regime. This is rather surprising, considering that the theory is completely parameter-free.
description: 18 pages, 3 figures
High order dark wavefront sensing simulations
Creators: name: Ragazzoni, Roberto
name: Arcidiacono, Carmelo
name: Farinato, Jacopo
name: Viotto, Valentina
name: Bergomi, Maria
name: Dima, Marco
name: Magrin, Demetrio
name: Marafatto, Luca
name: Greggio, Davide
name: Carolo, Elena
name: Vassallo, Daniele
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Dark wavefront sensing takes shape following quantum mechanics concepts in which one is able to "see" an object in one path of a two-arm interferometer using an as low as desired amount of light actually "hitting" the occulting object. A theoretical way to achieve such a goal, but in the realm of wavefront sensing, is represented by a combination of two unequal beams interferometer sharing the same incoming light, and whose difference in path length is continuously adjusted in order to show different signals for different signs of the incoming perturbation. Furthermore, in order to obtain this in white light, the path difference should be properly adjusted vs the wavelength used. While we incidentally describe how this could be achieved in a true optomechanical setup, we focus our attention to the simulation of a hypothetical "perfect" dark wavefront sensor of this kind in which white light compensation is accomplished in a perfect manner and the gain is selectable in a numerical fashion. Although this would represent a sort of idealized dark wavefront sensor that would probably be hard to match in the real glass and metal, it would also give a firm indication of the maximum achievable gain or, in other words, of the prize for achieving such device. Details of how the simulation code works and first numerical results are outlined along with the perspective for an in-depth analysis of the performances and its extension to more realistic situations, including various sources of additional noise.
description: 9 pages, 6 figures, Proceeding 9909-242 of the SPIE Astronomical Telescopes + Instrumentation 2016, 26 June-1 July 2016 Edinburgh, Scotland, UK
Can local dynamics enhance entangling power?
Creators: name: Jonnadula, Bhargavi
name: Mandayam, Prabha
name: Zyczkowski, Karol
name: Lakshminarayan, Arul
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: It is demonstrated here that local dynamics have the ability to strongly modify the entangling power of unitary quantum gates acting on a composite system. The scenario is common to numerous physical systems, in which the time evolution involves local operators and nonlocal interactions. To distinguish between distinct classes of gates with zero entangling power we introduce a complementary quantity called gate-typicality and study its properties. Analyzing multiple applications of any entangling operator interlaced with random local gates, we prove that both investigated quantities approach their asymptotic values in a simple exponential form. This rapid convergence to equilibrium, valid for subsystems of arbitrary size, is illustrated by studying multiple actions of diagonal unitary gates and controlled unitary gates.
description: 7 pages, 3 figures
The first four-color photometric investigation of the W UMa type contact binary V868 Mon
Creators: name: Xiao, Zhou
name: Shengbang, Qian
name: Jiajia, He
name: Jia, Zhang
name: Linqiao, Jiang
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The first four-color light curves of V868 Mon in the $B$ $V$ $R_c$ and $I_c$ bands are presented and analyzed by using the Wilson-Devinney method of the 2013 version. It is discovered that V868 Mon is an A-subtype contact binary (f=$58.9\,\%$) with a large temperature difference of 916$K$ between the two components. Using the eight new times of light minimum determined by the authors together with those collected from literatures, the authors found that the general trend of the observed-calculate ($O$-$C$) curve shows a upward parabolic variation that corresponds to a long-term increase in the orbital period at a rate of $dP/dt=9.38\times{10^{-7}}day\cdot year^{-1}$. The continuous increase may be caused by a mass transfer from the less massive component to the more massive one.
Pressure profiles of nonuniform two-dimensional atomic Fermi gases
Creators: name: Martiyanov, Kirill
name: Barmashova, Tatiana
name: Makhalov, Vasiliy
name: Turlapov, Andrey
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: Spatial profiles of the pressure have been measured in atomic Fermi gases with primarily 2D kinematics. The in-plane motion of the particles is confined by a gaussian-shape potential. The two-component deeply-degenerate Fermi gases are prepared at different values of the s-wave attraction. The pressure profile is found using the force-balance equation, from the measured density profile and the trapping potential. The pressure is compared to zero-temperature models within the local density approximation. In the weakly-interacting regime, the pressure lies above a Landau Fermi-liquid theory and below the ideal-Fermi-gas model, whose prediction coincides with that of the Cooper-pair mean-field theory. The values closest to the data are provided by the approach where the mean-field of Cooper pairs is supplemented with fluctuations. In the regime of strong interactions, in response to the increasing attraction, the pressure shifts below this model reaching lower values calculated within Monte Carlo methods. Comparison to models shows that interaction-induced departure from 2D kinematics is either small or absent. In particular, comparison with a lattice Monte Carlo suggests that kinematics is 2D in the strongly-interacting regime.
The growth of the central region by acquisition of counter-rotating gas in star-forming galaxies
Creators: name: Chen, Yan-Mei
name: Shi, Yong
name: Tremonti, Christy A.
name: Bershady, Matt
name: Merrifield, Michael
name: Emsellem, Eric
name: Jin, Yi-Fei
name: Huang, Song
name: Fu, Hai
name: Wake, David A.
name: Bundy, Kevin
name: Stark, David
name: Lin, Lihwai
name: Argudo-Fernandez, Maria
name: Bergmann, Thaisa Storchi
name: Bizyaev, Dmitry
name: Brownstein, Joel
name: Bureau, Martin
name: Chisholm, John
name: Drory, Niv
name: Guo, Qi
name: Hao, Lei
name: Hu, Jian
name: Li, Cheng
name: Li, Ran
name: Lopes, Alexandre Roman
name: Pan, Kai-Ke
name: Riffel, Rogemar A.
name: Thomas, Daniel
name: Wang, Lan
name: Westfall, Kyle
name: Yan, Ren-Bin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Galaxies grow through both internal and external processes. In about 10% of nearby red galaxies with little star formation, gas and stars are counter-rotating, demonstrating the importance of external gas acquisition in these galaxies. However, systematic studies of such phenomena in blue, star-forming galaxies are rare, leaving uncertain the role of external gas acquisition in driving evolution of blue galaxies. Based on new measurements with integral field spectroscopy of a large representative galaxy sample, we find an appreciable fraction of counter-rotators among blue galaxies (9 out of 489 galaxies). The central regions of blue counter-rotators show younger stellar populations and more intense, ongoing star formation than their outer parts, indicating ongoing growth of the central regions. The result offers observational evidence that the acquisition of external gas in blue galaxies is possible; the interaction with pre-existing gas funnels the gas into nuclear regions (< 1 kpc) to form new stars.
description: 20 pages, 7 figures, 1 table
Detection of exposed H$_2$O ice on the nucleus of comet 67P/Churyumov-Gerasimenko
Creators: name: Barucci, M. A.
name: Filacchione, G.
name: Fornasier, S.
name: Raponi, A.
name: Deshapriya, J. D. P.
name: Tosi, F.
name: Feller, C.
name: Ciarniello, M.
name: Sierks, H.
name: Capaccioni, F.
name: Pommerol, A.
name: Massironi, M.
name: Oklay, N.
name: Merlin, F.
name: Vincent, J. -B.
name: Fulchignoni, M.
name: Guilbert-Lepoutre, A.
name: Perna, D.
name: Capria, M. T.
name: Hasselmann, P. H.
name: Rousseau, B.
name: Barbieri, C.
name: Bockelee-Morvan, D.
name: Lamy, P. L.
name: De Sanctis, C.
name: Rodrigo, R.
name: Erard, S.
name: Koschny, D.
name: Leyrat, C.
name: Rickman, H.
name: Drossart, P.
name: Keller, H. U.
name: A'Hearn, M. F.
name: Arnold, G.
name: Bertaux, J. -L.
name: Bertini, I.
name: Cerroni, P.
name: Cremonese, G.
name: Da Deppo, V.
name: Davidsson, B. J. R.
name: El-Maarry
name: Fonti, S.
name: Fulle, M.
name: Groussin, O.
name: Guttler, C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Since the orbital insertion of the Rosetta spacecraft, comet 67P/Churyumov-Gerasimenko (67P/C-G) has been mapped by OSIRIS camera and VIRTIS spectro-imager, producing a huge quantity of images and spectra of the comet's nucleus. The aim of this work is to search for the presence of H$_2$O on the nucleus which, in general, appears very dark and rich in dehydrated organic material. After selecting images of the bright spots which could be good candidates to search for H$_2$O ice, taken at high resolution by OSIRIS, we check for spectral cubes of the selected coordinates to identify these spots observed by VIRTIS. The selected OSIRIS images were processed with the OSIRIS standard pipeline and corrected for the illumination conditions for each pixel using the Lommel-Seeliger disk law. The spots with higher I/F were selected and then analysed spectrophotometrically and compared with the surrounding area. We selected 13 spots as good targets to be analysed by VIRTIS to search for the 2 micron absorption band of water ice in the VIRTIS spectral cubes. Out of the 13 selected bright spots, eight of them present positive H$_2$O ice detection on the VIRTIS data. A spectral analysis was performed and the approximate temperature of each spot was computed. The H$_2$O ice content was confirmed by modeling the spectra with mixing (areal and intimate) of H$_2$O ice and dark terrain, using Hapke's radiative transfer modeling. We also present a detailed analysis of the detected spots.
description: paper in press in A&A, 13 pages, 6 figures
A Guide to the Seismic Wavefield as seen by DAS
Creators: name: Kennett, Brian L.N.
Publisher: name: The Australian National University
Year: 2024
Subjects: Seismology

description: Distributed acoustic sensing (DAS) exploiting fibre optic cables provides high-density sampling of the seismic wavefield. Scattered returns from multiple laser pulses provide local averages of strain rate over a finite gauge length. The nature of DAS signal depends on the orientation of the cable with respect to the passing seismic waves, and so differs from conventional seismometer response. For local events the dominant part of the strain rate can be extracted from the difference of ground velocity resolved along the fibre at the ends of the gauge interval. For more distant events the response at seismic frequencies can be represented as the acceleration along the fibre modulated by the wave slowness resolved in the same direction, which means there is a strong dependence on cable orientation. The work concentrates on direct interpretation of DAS signals. The nature of the wavefield can be elucidated with the aid of frequency--slowness domain representations for body waves and surface waves that are also suitable for simulation of DAS response. The DAS wavefield is examined at local, regional and global scales. In each case examples of DAS recordings are presented, together with a discussion of suitable ways of simulating the DAS response for the particular regime. There is an emphasis on the specific nature of DAS records and the way in which sensitivity to cable orientation relative to passing wavefronts can be utilised to advantage. The exploitation of ambient noise via cross-correlation of DAS channels is also considered using a simple visual approach to examine the effect of cable geometry on the extraction of Rayleigh and Love wave signals. The slowness-domain representation of the DAS signal allows analysis of the array response of cable configurations under stacking indicating a bias due to the slowness weighting associated with the effect of gauge length. Unlike seismometer arrays the response is not described by a single generic stacking function. Suitable designs for DAS layouts are presented for both stacking of distant events and cross-correlation studies.
Spectral Singularities in the TE and TM modes of a PT-Symmetric Slab System: Optimal conditions for realizing a CPA-Laser
Creators: name: Mostafazadeh, Ali
name: Sarisaman, Mustafa
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Among the interesting outcomes of the study of the physical applications of spectral singularities in PT-symmetric optical systems is the discovery of CPA-lasers. These are devices that act both as a threshold laser and a coherent perfect absorber (CPA) for the same values of their physical parameters. Unlike a homogeneous slab that is made to act as a CPA, a slab CPA-laser would absorb the incident waves coming from the left and right of the device provided that they have appropriate intensity and phase contrasts. We provide a comprehensive study of one of the simplest experimentally accessible examples of a CPA-laser, namely a PT-symmetric optical slab system consisting of a balanced pair of adjacent or separated gain and loss components. In particular, we give a closed form expression describing the spectral singularities of the system which correspond to its CPA-laser configurations. We determine the intensity and phase contrasts for the TE and TM waves that are emitted (absorbed) whenever the slab acts as a laser (CPA). We also investigate the behavior of the time-averaged energy density and Poynting vector for these waves. This is necessary for determining the optimal values of the physical parameters of the system that make it act as a CPA-laser. These turn out to correspond to situations where the separation distance $s$ between the gain and loss layers is an odd multiple of a characteristic length scale $s_0$. A curious by-product of our study is that, except for the cases where $s$ is an even integer multiple of $s_0$, there is a critical angle of polarization beyond which the energy of the waves emitted from the lossy layer can be larger than the energy of those emitted from the gain layer.
description: 28 pages, 6 tables, 16 figures
The Photometric Investigation of V921 Her using the Lunar-based Ultraviolet Telescope of Chang'e-3 mission
Creators: name: Zhou, Xiao
name: Qian, Sheng-Bang
name: Zhang, Jia
name: Li, Lin-Jia
name: Wang, Qi-Shan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The light curve of V921 Her in ultraviolet band observed by the Lunar-based Ultraviolet Telescope (LUT) is analyzed by the Wilson-Devinney code. Our solutions conclude that V921 Her is an early type marginal contact binary system with an additional close-in component. The binary system is under poor thermal contact with a temperature difference of nearly $700K$ between the two components. The close-in component contributes about $19\,\%$ of the total luminosity in the triple system. Combining the radial velocity study together with our photometric solutions, the mass of the primary star and secondary one are calculated to be $M_1 = 1.784(\pm0.055)M_\odot$, $M_2 = 0.403(\pm0.012)M_\odot$. The evolutionary scenario of V921 Her is discussed. All times of light minimum of V921 Her available in the bibliography are taken into account and the $O - C$ curve is analyzed for the first time. The most probable fitting results are discussed in the paper, which also confirm the existence of a third component ($P_3=10.2$ year) around the binary system. The period of V921 Her is also undergoing a continuously rapid increase at a rate of $dP/dt=+2.79\times{10^{-7}}day\cdot year^{-1}$, which may due to mass transfer from the less massive component to the more massive one.
Incorporating Clicks, Attention and Satisfaction into a Search Engine Result Page Evaluation Model
Creators: name: Chuklin, Aleksandr
name: de Rijke, Maarten
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences
subject: H.3.3

description: Modern search engine result pages often provide immediate value to users and organize information in such a way that it is easy to navigate. The core ranking function contributes to this and so do result snippets, smart organization of result blocks and extensive use of one-box answers or side panels. While they are useful to the user and help search engines to stand out, such features present two big challenges for evaluation. First, the presence of such elements on a search engine result page (SERP) may lead to the absence of clicks, which is, however, not related to dissatisfaction, so-called "good abandonments." Second, the non-linear layout and visual difference of SERP items may lead to non-trivial patterns of user attention, which is not captured by existing evaluation metrics. In this paper we propose a model of user behavior on a SERP that jointly captures click behavior, user attention and satisfaction, the CAS model, and demonstrate that it gives more accurate predictions of user actions and self-reported satisfaction than existing models based on clicks alone. We use the CAS model to build a novel evaluation metric that can be applied to non-linear SERP layouts and that can account for the utility that users obtain directly on a SERP. We demonstrate that this metric shows better agreement with user-reported satisfaction than conventional evaluation metrics.
description: CIKM2016, Proceedings of the 25th ACM International Conference on Information and Knowledge Management. 2016
The Nuclear Activities of Nearby S0 Galaxies
Creators: name: Xiao, Mengyuan
name: Gu, Qiusheng
name: Chen, Yanmei
name: Zhou, Luwenjia
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a study of nuclear activities in nearby S0 galaxies. After cross-matching the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) with the Third Reference Catalog of Bright Galaxies (RC3) and visually checking the SDSS images, we derive a sample of 583 S0 galaxies with the central spectrophotometric information. In order to separate nebular emission lines from the underlying stellar contribution, we fit the stellar population model to the SDSS spectra of these S0 galaxies. According to the BPT diagram, we find that $8\%$ of S0 galaxies show central star-forming activity, while the fractions of Seyfert, Composite and LINERs are 2\%, 8\%, and 21.4\%, respectively. We also find that star-forming S0s have the lowest stellar masses, over one magnitude lower than the others, and that the active S0s locate mainly in the sparse environment, while the normal S0s in the dense environment, which might suggest that the environment plays an important role in quenching star formation and/or AGN activity in S0 galaxies. By performing bulge-disk decomposition of 45 star-forming S0s in {\em g}- and {\em r}-bands with the 2D fitting software \textsc{Galfit}, as well as exploiting the catalog of 2D photometric decompositions of \citet{Meert2015}, we find that the bulges of $\sim$ 1/3 star-forming S0 galaxies (16/45) are bluer than their disks, while for other types of S0s, the bulge and disk components show similar color distributions. Besides, the Sérsic index of most star-forming S0s bulges is less than 2, while for normal S0s, it is between 2 and 6.
description: 15 pages, 13 figures, accepted to ApJ (831:63)
Comparison of GHRSST SST analysis in the Arctic Ocean and Alaskan coastal waters using saildrones: Application to a use case in the Y-K Delta
Creators: name: Vazquez-Cuervo, Jorge
Publisher: name: Zenodo
Year: 2022

description: Short abstract There is high demand for complete satellite SST maps (or L4 SST analyses) of the Arctic regions to monitor the rapid environmental changes occurring at high latitudes. Although there is a plethora of L4 SST products to choose from, satellite-based products evolve constantly with the advent of new satellites and frequent changes in SST algorithms with the intent of improving absolute accuracies. The constant change of these products, as reflected by the version product, make it necessary to do periodic validations against in situ data. Eight of these L4 products are compared here against saildrone data from two 2019 campaigns in the western Arctic, as part of the MISST project. The accuracy of the different products is estimated using different statistical methods, from standard and robust statistics to Taylor diagrams. Results are also examined in terms of spatial scales of variability using spectral analysis. The three products with the best performance at this point and time are used in a case study of the thermal features of the Yukon-Kuskokwim delta. Comparisons are also made with Salinity data from NASA’s Soil Moisture Active Passive Mission. Overall, the statistical analyses show that two L4 SST products had consistently better relative accuracy when compared to the saildrone subsurface temperatures. Those are the NOAA/NCEI DOISST and the RSS MWOI SSTs. Results will also be presented on comparing the spectral variance and feature resolution. Comparisons are all done using Saildrone as the reference
Nonclassical spectral asymptotics and Dixmier traces: From circles to contact manifolds
Creators: name: Gimperlein, Heiko
name: Goffeng, Magnus
Publisher: name: arXiv
Year: 2016
Subjects: subject: Spectral Theory (math.SP)
subject: Functional Analysis (math.FA)
subject: Operator Algebras (math.OA)
subject: FOS: Mathematics

description: We consider the spectral behavior and noncommutative geometry of commutators $[P,f]$, where $P$ is an operator of order $0$ with geometric origin and $f$ a multiplication operator by a function. When $f$ is Hölder continuous, the spectral asymptotics is governed by singularities. We study precise spectral asymptotics through the computation of Dixmier traces; such computations have only been considered in less singular settings. Even though a Weyl law fails for these operators, and no pseudo-differential calculus is available, variations of Connes' residue trace theorem and related integral formulas continue to hold. On the circle, a large class of non-measurable Hankel operators is obtained from Hölder continuous functions $f$, displaying a wide range of nonclassical spectral asymptotics beyond the Weyl law. The results extend from Riemannian manifolds to contact manifolds and noncommutative tori.
description: 40 pages
Three-Dimensional Reddening Map for Stars from 2MASS Photometry: The Method and the First Results
Creators: name: Gontcharov, George
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The first results of the construction of a 3D reddening map for stars within 1600 pc of the Sun are presented. Analysis of the distribution of 70 million stars from the 2MASS catalog with the most accurate photometry on the (J-Ks) - Ks diagram supplemented with Monte Carlo simulations has shown that one of the maxima of this distribution corresponds to F-type dwarfs and subgiants with a mean absolute magnitude MKs=2.5m. The shift of this maximum toward large (J-Ks) with increasing $Ks$ reflects the reddening of these stars with increasing heliocentric distance. The distribution of the sample of stars over Ks, l, and b cells with corresponds to their distribution over 3D spatial cells. As a result, the reddening E(J-Ks) has been determined with an accuracy of 0.03m for spatial cells with a side of 100 pc. All of the known large absorbing clouds within 1600 pc of the Sun have manifested themselves in the results obtained. The distances to the near and far edges of the clouds have been determined with a relative accuracy of 15\%. The cases where unknown clouds are hidden behind known ones on the same line of sight have been found. The distance dependence of reddening is considered for various Galactic latitudes and longitudes. The absorbing matter of the Gould Belt is shown to manifest itself at latitudes up to 40 deg and within 600 pc of the Sun. The size and influence of the Gould Belt may have been underestimated thus far. The absorbing matter at latitudes up to 60 deg and within 1600 pc of the Sun has been found to be distributed predominantly in the first and second quadrants in S hemisphere and in the third and fourth quadrants in N hemisphere. A nonrandom orientation of the clouds relative to the Sun is possible. The mass of the baryonic dark matter in solar neighborhoods can then be considerably larger than is generally believed.
description: 6 figures, 3 tables, an erratum is corrected in the Table 1
Cloud Benchmarking For Maximising Performance of Scientific Applications
Creators: name: Varghese, Blesson
name: Akgun, Ozgur
name: Miguel, Ian
name: Thai, Long
name: Barker, Adam
Publisher: name: arXiv
Year: 2016
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: How can applications be deployed on the cloud to achieve maximum performance? This question is challenging to address with the availability of a wide variety of cloud Virtual Machines (VMs) with different performance capabilities. The research reported in this paper addresses the above question by proposing a six step benchmarking methodology in which a user provides a set of weights that indicate how important memory, local communication, computation and storage related operations are to an application. The user can either provide a set of four abstract weights or eight fine grain weights based on the knowledge of the application. The weights along with benchmarking data collected from the cloud are used to generate a set of two rankings - one based only on the performance of the VMs and the other takes both performance and costs into account. The rankings are validated on three case study applications using two validation techniques. The case studies on a set of experimental VMs highlight that maximum performance can be achieved by the three top ranked VMs and maximum performance in a cost-effective manner is achieved by at least one of the top three ranked VMs produced by the methodology.
description: 14 pages, accepted to the IEEE Transactions on Cloud Computing on 31 July 2016
Quantum emitter dipole-dipole interactions in nanoplasmonic systems
Creators: name: Nečada, Marek
name: Martikainen, Jani-Petri
name: Törmä, Päivi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We introduce a generalized Dicke-like model to describe two-level systems coupled with a single bosonic mode. In addition, the two-level systems mutually interact via direct dipole-dipole interaction. We apply the model to an ensemble of dye molecules coupled to a plasmonic excitation in a metallic nanoparticle and study how the dipole-dipole interaction and configurational randomness introduced to the system affect the energy spectra. Comparing the system eigenenergies obtained by our model with the light spectra from a multiple-scattering simulation, we suggest a way to identify dark modes in our model. Finally, we perform a parameter sweep in order to determine the scaling properties of the system and to classify the regions of the parameter space where the dipole-dipole interactions can have significant effects.
Managing Rail Logistics Risks Faced by Shippers: A Value-at-Risk Approach
Creators: name: Bullock, David W.
name: Wilson, William W.
name: Wilson, Isaac
name: Bullock, David W.
name: Wilson, William W.
name: Wilson, Isaac
Publisher: name: Unknown
Year: 2022
Subjects: subject: International Relations/Trade
subject: Public Economics
subject: logistics
subject: value-at-risk
subject: material requirement planning
subject: subject matter expert time series
subject: primary and secondary railcar marketsw

description: In addition to the traditional market price risks, origin shippers of grains and oilseeds face risks related to the costs associated with the handling, storage, and transport of crops to their destination markets. To more closely examine the nature of these risks, a Monte Carlo optimization model was constructed using the Material Requirement Planning (MRP) methodology. The goal of the model was to minimize the mean and 5% value-at-risk (VaR) of the sum of these associated costs. The primary decision variable was the number of unit trains to purchase in the primary rail market. The model was also subjected to additional sensitivity and stress analysis to analyze the properties of the optimal results. A primary observation derived from this analysis is the importance of the primary and secondary railcar markets to the management of these risks, both from an informational and risk management perspective. Another key driver was the ability to manage the seasonality of farmer deliveries via forward contracting to capture returns to storage. Finally, another key contribution of this study is to demonstrate the utility of using subject matter expert (SME) time series modeling in Monte Carlo simulation.
Group Sparse Regularization for Deep Neural Networks
Creators: name: Scardapane, Simone
name: Comminiello, Danilo
name: Hussain, Amir
name: Uncini, Aurelio
Publisher: name: arXiv
Year: 2016
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: In this paper, we consider the joint task of simultaneously optimizing (i) the weights of a deep neural network, (ii) the number of neurons for each hidden layer, and (iii) the subset of active input features (i.e., feature selection). While these problems are generally dealt with separately, we present a simple regularized formulation allowing to solve all three of them in parallel, using standard optimization routines. Specifically, we extend the group Lasso penalty (originated in the linear regression literature) in order to impose group-level sparsity on the network's connections, where each group is defined as the set of outgoing weights from a unit. Depending on the specific case, the weights can be related to an input variable, to a hidden neuron, or to a bias unit, thus performing simultaneously all the aforementioned tasks in order to obtain a compact network. We perform an extensive experimental evaluation, by comparing with classical weight decay and Lasso penalties. We show that a sparse version of the group Lasso penalty is able to achieve competitive performances, while at the same time resulting in extremely compact networks with a smaller number of input features. We evaluate both on a toy dataset for handwritten digit recognition, and on multiple realistic large-scale classification problems.
Open flavor strong decays
Creators: name: García-Tecocoatzi, H.
name: Bijker, R.
name: Ferretti, J.
name: Galatà, G.
name: Santopinto, E.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this contribution, we discuss the results of a QM calculation of the open-flavor strong decays of **** light nucleon resonances. These are the results of a recent calculation, where we used a modified $^3P_0$ model for the amplitudes and the U(7) algebraic model and the Hypercentral Quark Model to predict the baryon spectrum. The decay amplitudes are compared with the existing experimental data.
description: Invited talk presented at NSTAR:Nucleon Resonances: From Photoproduction to High Photon Virtualities
Marginally stable and turbulent boundary layers in low-curvature Taylor-Couette flow
Creators: name: Brauckmann, Hannes J.
name: Eckhardt, Bruno
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Marginal stability arguments are used to describe the rotation-number dependence of torque in Taylor-Couette (TC) flow for radius ratios $η\geq 0.9$ and shear Reynolds number $Re_S=2\times 10^4$. With an approximate representation of the mean profile by piecewise linear functions, characterized by the boundary-layer thicknesses at the inner and outer cylinder and the angular momentum in the center, profiles and torques are extracted from the requirement that the boundary layers represent marginally stable TC subsystems and that the torque at the inner and outer cylinder coincide. This model then explains the broad shoulder in the torque as a function of rotation number near $R_Ω\approx 0.2$. For rotation numbers $R_Ω< 0.07$ the TC stability conditions predict boundary layers in which shear Reynolds numbers are very large. Assuming that the TC instability is bypassed by some shear instability, a second maximum in torque appears, in very good agreement with numerical simulations. The results show that, despite the shortcomings of marginal stability theory in other cases, it can explain quantitatively the non-monotonic torque variation with rotation number for both the broad maximum as well as the narrow maximum.
description: 18 pages, 9 figures
Magnetic field strength in an intermediate-velocity ionized filament in the First Galactic Quadrant
Creators: name: Stil, Jeroen M.
name: Hryhoriw, Athena
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We investigate the magnetic field in an intermediate-velocity filament for which the H$α$ intensity in the WHAM survey correlates with excess Faraday rotation of extragalactic radio sources over the length of the filament from b ~ 20 degr. to b ~ 55 degr. The density-weighted mean magnetic field is 2.8 +/- 0.8 microgauss, derived from rotation measures and an empirical relation between H-alpha emission measure and dispersion measure from Berkhuijsen et al. (2006). In view of the uncertainties in the derived magnetic field strength, we propose an alternative use of the available data, rotation measure and emission measure, to derive a lower limit to the Alfven speed, weighted by electron density n_e^1.5. We find lower limits to the Alfven speed that are comparable to, or larger than the sound speed in a 10^4 K plasma, and conclude that the magnetic field is dynamically important. We discuss the role of intermediate-velocity gas as a locus of Faraday rotation in the interstellar medium, and propose this lower limit to the Alfven speed may also be applicable to Faraday rotation by galaxy clusters.
description: Accepted for publication in The Astrophysical Journal. 10 pages, 5 figures, some in colour
Electromagnetic description of three-dimensional time-reversal invariant ponderable topological insulators
Creators: name: Martín-Ruiz, Alberto
name: Cambiaso, Mauro
name: Urrutia, Luis F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A general technique to analyze the classical interaction between ideal topological insulators, and electromagnetic sources and fields, has been previously elaborated. Nevertheless it is not immediately applicable in the laboratory as it fails to describe real ponderable media. In this work we provide a description of real topologically insulating materials taking into account their dielectric and magnetic properties. For inhomogeneous permittivity and permeability, the problem of finding the Green's function must be solved in an ad hoc manner. Nevertheless, the physically feasible cases of piecewise constant $\varepsilon, μ$ and $θ$ make the problem tractable, where $θ$ encodes the topological magnetoelectric polarizability properties of the medium. To this end we employ the Green's function method to find the fields resulting form the interaction between these materials and electromagnetic sources. Furthermore we exploit the fact that in the cases here studied, the full Green's function can be successfully found if the Green's function of the corresponding ponderable media with $θ= 0$ is known. Our results, satisfactorily reproduce previously existing ones and also generalize some others. The method here elaborated can be exploited to determine the electromagnetic fields for more general configurations aiming to measure the interaction between real 3D topological insulators and electromagnetic fields.
description: Accepted for publication in PRD
Automatic Detection of Omega Signals Captured by the Poynting Flux Analyzer (PFX) on Board the Akebono Satellite
Creators: name: Suarjaya, I Made Agus Dwi
name: Kasahara, Yoshiya
name: Goto, Yoshitaka
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The Akebono satellite was launched in 1989 to observe the Earth's magnetosphere and plasmasphere. Omega was a navigation system with 8 ground stations transmitter and had transmission pattern that repeats every 10 s. From 1989 to 1997, the PFX on board the Akebono satellite received signals at 10.2 kHz from these stations. Huge amounts of PFX data became valuable for studying the propagation characteristics of VLF waves in the ionosphere and plasmasphere. In this study, we introduce a method for automatic detection of Omega signals from the PFX data in a systematic way, it involves identifying a transmission station, calculating the delay time, and estimating the signal intensity. We show the reliability of the automatic detection system where we able to detect the omega signal and confirmed its propagation to the opposite hemisphere along the Earth's magnetic field lines. For more than three years (39 months), we detected 43,734 and 111,049 signals in the magnetic and electric field, respectively, and demonstrated that the proposed method is powerful enough for the statistical analyses.
description: 8 pages, 11 figures
Non-equilibrium fluctuations of a semi-flexible filament driven by active cross-linkers
Creators: name: Weber, Ines
name: Appert-Rolland, Cécile
name: Schehr, Grégory
name: Santen, Ludger
Publisher: name: arXiv
Year: 2016
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Subcellular Processes (q-bio.SC)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: The cytoskeleton is an inhomogeneous network of semi-flexible filaments, which are involved in a wide variety of active biological processes. Although the cytoskeletal filaments can be very stiff and embedded in a dense and cross-linked network, it has been shown that, in cells, they typically exhibit significant bending on all length scales. In this work we propose a model of a semi-flexible filament deformed by different types of cross-linkers for which one can compute and investigate the bending spectrum. Our model allows to couple the evolution of the deformation of the semi-flexible polymer with the stochastic dynamics of linkers which exert transversal forces onto the filament. We observe a $q^{-2}$ dependence of the bending spectrum for some biologically relevant parameters and in a certain range of wavenumbers $q$. However, generically, the spatially localized forcing and the non-thermal dynamics both introduce deviations from the thermal-like $q^{-2}$ spectrum.
description: 9 pages, 5 figures
Tunable ground states in helical $p$-wave Josephson junctions
Creators: name: Cheng, Qiang
name: Zhang, Kunhua
name: Yu, Dongyang
name: Chen, Chongju
name: Zhang, Yinhan
name: Jin, Biao
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study new types of Josephson junctions composed of helical $p$-wave superconductors with $k_{x}\hat{x}\pm k_{y}\hat{y}$ and $k_{y}\hat{x}\pm k_{x}\hat{y}$-pairing symmetries using quasiclassical Green's functions with the generalized Riccati parametrization. The junctions can host rich ground states: $π$ phase, $0+π$ phase, $φ_{0}$ phase and $φ$ phase. The phase transition can be tuned by rotating the magnetization in the ferromagnetic interface. We present the phase diagrams in the parameter space formed by the orientation of the magnetization or by the magnitude of the interfacial potentials. The selection rules for the lowest order current which are responsible for the formation of the rich phases are summarized from the current-phase relations based on the numerical calculation. We construct a Ginzburg-Landau type of free energy for the junctions with ${\bf{d}}$-vectors and the magnetization, which not only reveals the interaction forms of spin-triplet superconductivity and ferromagnetism but also can directly leads to the selection rules. In addition, the energies of the Andreev bound states and the novel symmetries in the current-phase relations are also investigated. Our results are helpful both in the prediction of the novel Josephson phases and in the design of the quantum circuits.
description: 23 pages,15 figures