cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A Search for Very High-Energy Gamma Rays from the Missing Link Binary Pulsar J1023+0038 with VERITAS
Creators: name: Aliu, E.
name: Archambault, S.
name: Archer, A.
name: Benbow, W.
name: Bird, R.
name: Biteau, J.
name: Buchovecky, M.
name: Buckley, J. H.
name: Bugaev, V.
name: Byrum, K.
name: Cardenzana, J. V
name: Cerruti, M.
name: Chen, X.
name: Ciupik, L.
name: Connolly, M. P.
name: Cui, W.
name: Dickinson, H. J.
name: Eisch, J. D.
name: Falcone, A.
name: Feng, Q.
name: Finley, J. P.
name: Fleischhack, H.
name: Flinders, A.
name: Fortin, P.
name: Fortson, L.
name: Furniss, A.
name: Gillanders, G. H.
name: Griffin, S.
name: Grube, J.
name: Gyuk, G.
name: Hütten, M.
name: Håkansson, N.
name: Holder, J.
name: Humensky, T. B.
name: Johnson, C. A.
name: Kaaret, P.
name: Kar, P.
name: Kelley-Hoskins, N.
name: Kertzman, M.
name: Kieda, D.
name: Krause, M.
name: Lang, M. J.
name: Loo, A.
name: Maier, G.
name: McArthur, S.
name: McCann, A.
name: Meagher, K.
name: Moriarty, P.
name: Mukherjee, R.
name: Nguyen, T.
name: Nieto, D.
name: de Bhróithe, A. O'Faoláin
name: Ong, R. A.
name: Otte, A. N.
name: Pandel, D.
name: Park, N.
name: Pelassa, V.
name: Petrashyk, A.
name: Pohl, M.
name: Popkow, A.
name: Pueschel, E.
name: Quinn, J.
name: Ragan, K.
name: Reynolds, P. T.
name: Richards, G. T.
name: Roache, E.
name: Rulten, C.
name: Santander, M.
name: Sembroski, G. H.
name: Shahinyan, K.
name: Smith, A. W.
name: Staszak, D.
name: Telezhinsky, I.
name: Tucci, J. V.
name: Tyler, J.
name: Varlotta, A.
name: Vincent, S.
name: Wakely, S. P.
name: Weiner, O. M.
name: Weinstein, A.
name: Wilhelm, A.
name: Williams, D. A.
name: Zitzer, B.
name: Chernyakova, M.
name: Roberts, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The binary millisecond radio pulsar PSR J1023+0038 exhibits many characteristics similar to the gamma-ray binary system PSR B1259--63/LS 2883, making it an ideal candidate for the study of high-energy non-thermal emission. It has been the subject of multi-wavelength campaigns following the disappearance of the pulsed radio emission in 2013 June, which revealed the appearance of an accretion disk around the neutron star. We present the results of very high-energy gamma-ray observations carried out by VERITAS before and after this change of state. Searches for steady and pulsed emission of both data sets yield no significant gamma-ray signal above 100 GeV, and upper limits are given for both a steady and pulsed gamma-ray flux. These upper limits are used to constrain the magnetic field strength in the shock region of the PSR J1023+0038 system. Assuming that very high-energy gamma rays are produced via an inverse-Compton mechanism in the shock region, we constrain the shock magnetic field to be greater than $\sim$2 G before the disappearance of the radio pulsar and greater than $\sim$10 G afterwards.
description: 7 pages, 3 figures, accepted for publication in ApJ
Biorisk Management Case Study: Science
Creators: name: Hurtley, Stella
name: Hoffmann, Connor
name: Salm, Melissa
name: Greene, Daniel
name: Brink, Kathryn
Publisher: name: Stanford Digital Repository
Year: 2023
Subjects: subject: Risk management

description: Science is the flagship journal of the American Association for the Advancement of Science (AAAS). The journal is highly competitive, publishing manuscripts that demonstrate significant innovations in their methods or results that significantly advance scientific understanding. Science:
• developed its dual-use research risk management processes in response to a high-profile debate over its publication of an H5N1 influenza gain-of-function experiment.
• piloted a Materials, Design, Analysis, and Reporting framework and checklist, which included a field for authors to report whether their experiments are subject to dual-use research of concern (DURC) oversight.
• mitigates risks by communicating in its articles whether research received additional dual-use oversight or involved additional biosafety and biosecurity safeguards.
• relies on the individual expertise of its reviewing editors and a small network of peers when making dual-use review decisions.
Generalized Suffix Tree based Multiple Sequence Alignment for Service Virtualization
Creators: name: Schneider, Jean-Guy
name: Mandile, Peter
name: Versteeg, Steve
Publisher: name: arXiv
Year: 2016
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Assuring quality of contemporary software systems is a very challenging task due to the often large complexity of the deployment environments in which they will operate. Service virtualization is an approach to this challenge where services within the deployment environment are emulated by synthesising service response messages from models or by recording and then replaying service interaction messages with the system. Record-and-replay techniques require an approach where (i) message prototypes can be derived from recorded system interactions (i.e. request-response sequences), (ii) a scheme to match incoming request messages against message prototypes, and (iii) the synthesis of response messages based on similarities between incoming messages and the recorded system interactions. Previous approaches in service virtualization have required a multiple sequence alignment (MSA) algorithm as a means of finding common patterns of similarities and differences between messages required by all three steps. In this paper, we present a novel MSA algorithm based on Generalized Suffix Trees (GSTs). We evaluated the accuracy and efficiency of the proposed algorithm against six enterprise service message trace datasets, with the proposed algorithm performing up to 50 times faster than standard MSA approaches. Furthermore, the algorithm has applicability to other domains beyond service virtualization.
description: In Proceedings of 24th Australasian Software Engineering Conference (ASWEC2015), pp 48-57
A possible role for the merger of clusters/voids in the cosmological expansion
Creators: name: Mohammadi, S.
name: Yusofi, E.
name: Mohsenzadeh, M.
name: Salem, M. K.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this study, we use the merger process of clusters/voids in the role of variable dark energy fluid to alleviate the Hubble tension, which can lead to a balance in the cosmological expansion rate. To reach this target, we will introduce a modified form of energy density for cosmic fluid with the quadratic equation of state, and then we obtain Hubble, deceleration parameters, and luminosity distance for this fluid. To obtain the merger factor and other parameters of our model, we utilize the NONLINEARMODELFIT function within MATHEMATICA. By consideration of the local and global measurements of $\rm H_0$, and the equation of state parameter $w$ as the priory values and fitting our model with Observational Hubble Data (OHD) measurements, we will show that the merger of clusters/voids plays the role of balancing the cosmic expansion rate. Also, it will be shown that the model is more compatible than $w$CDM with the standard model to describe the accelerating universe.
description: 7 pages, 4 figures, 3 tables, According to the version accepted in MNRAS
Suites récurrentes linéaires d'ordre 2 à divisibilité forte
Creators: name: Bauval, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11B39, 11A05

description: We reprove twice, in a simpler but as elementary way, a result by Horák and Skula (1985) who determined, among all sequences of integers defined by $$u_1=1,\quad u_2=R,\quad u_{n+2}=Pu_{n+1}-Qu_n$$ for some integers $P,Q,R$, those which satisfy the strong divisibility condition $$\forall i,j\in\mathbb N^*\quad u_i\land u_j=\left|u_{i\land j}\right|,$$ where $\land$ denotes the greatest common divisor.
description: in French
Observations of the planetary nebula RWT 152 with OSIRIS/GTC
Creators: name: Aller, A.
name: Miranda, L. F.
name: Olguín, L.
name: Solano, E.
name: Ulla, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: RWT 152 is one of the few known planetary nebulae with an sdO central star. We present subarcsecond red tunable filter Halpha imaging and intermediate-resolution, long-slit spectroscopy of RWT 152 obtained with OSIRIS/GTC with the goal of analyzing its properties. The Halpha image reveals a bipolar nebula with a bright equatorial region and multiple bubbles in the main lobes. A faint circular halo surrounds the main nebula. The nebular spectra reveal a very low-excitation nebula with weak emission lines from H^+, He^+, and double-ionized metals, and absence of emission lines from neutral and single-ionized metals, except for an extremely faint [NII]6584 emission line. These spectra may be explained if RWT 152 is a density-bounded planetary nebula. Low nebular chemical abundances of S, O, Ar, N, and Ne are obtained in RWT 152, which, together with the derived high peculiar velocity ($\sim$ 92-131 km s$^{-1}$), indicate that this object is a halo planetary nebula. The available data are consistent with RWT 152 evolving from a low-mass progenitor ($\sim$ 1 M$_{\odot}$) formed in a metal-poor environment.
description: 10 pages, 6 figures, accepted for publication in MNRAS
Quantitative bound entanglement in two-qutrit states
Creators: name: Sentís, Gael
name: Eltschka, Christopher
name: Siewert, Jens
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Among the many facets of quantum correlations, bound entanglement has remained one the most enigmatic phenomena, despite the fact that it was discovered in the early days of quantum information. Even its detection has proven to be difficult, let alone its precise quantitative characterization. In this work, we present the exact quantification of entanglement for a two-parameter family of highly symmetric two-qutrit mixed states, which contains a sizable part of bound entangled states. We achieve this by explicitly calculating the convex-roof extensions of the linear entropy as well as the concurrence for every state within the family. Our results provide a benchmark for future quantitative studies of bipartite entanglement in higher-dimensional systems.
description: 6 pages, 3 figures
Lévy Transport in Slab Geometry of Inhomogeneous Media
Creators: name: Iomin, Alexander
name: Sandev, Trifce
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: 60J60, 33E12, 26A33, 34A08, 35R11, 60G50

description: We present a physical example, where a fractional (both in space and time) Schrödinger equation appears only as a formal effective description of diffusive wave transport in complex inhomogeneous media. This description is a result of the parabolic equation approximation that corresponds to the paraxial small angle approximation of the fractional Helmholtz equation. The obtained effective quantum dynamics is fractional in both space and time. As an example, Lévy flights in an infinite potential well are considered numerically. An analytical expression for the effective wave function of the quantum dynamics is obtained as well.
Visualization of defect-induced excitonic properties of the edges and grain boundaries in synthesized monolayer molybdenum disulfide
Creators: name: Yore, A. E.
name: Smithe, K. K. H.
name: Crumrine, W.
name: Miller, A.
name: Tuck, J. A.
name: Redd, B.
name: Pop, E.
name: Wang, Bin
name: Newaz, A. K. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDCs) are attractive materials for next generation nanoscale optoelectronic applications. Understanding nanoscale optical behavior of the edges and grain boundaries of synthetically grown TMDCs is vital for optimizing their optoelectronic properties. Elucidating the nanoscale optical properties of 2D materials through far-field optical microscopy requires a diffraction-limited optical beam diameter sub-micron in size. Here we present our experimental work on spatial photoluminescence (PL) scanning of large size ( $\geq 50$ microns) monolayer MoS$_2$ grown by chemical vapor deposition (CVD) using a diffraction limited blue laser beam spot (wavelength 405 nm) with a beam diameter as small as 200 nm allowing us to probe nanoscale excitonic phenomena which was not observed before. We have found several important features: (i) there exists a sub-micron width strip ($\sim 500$ nm) along the edges that fluoresces $\sim 1000 \%$ brighter than the region far inside; (ii) there is another brighter wide region consisting of parallel fluorescing lines ending at the corners of the zig-zag peripheral edges; (iii) there is a giant blue shifted A-excitonic peak, as large as $\sim 120$ meV, in the PL spectra from the edges. Using density functional theory calculations, we attribute this giant blue shift to the adsorption of oxygen dimers at the edges, which reduces the excitonic binding energy. Our results not only shed light on defect-induced excitonic properties, but also offer an attractive route to tailor optical properties at the TMDC edges through defect engineering.
description: 10 pages, 4 figures in Journal of Physical Chemistry C, 2016
The Origin Story at the End of the Universe: An Empirical Inquiry into a Cosmology of Problems - Introduction
Creators: name: De Sutter, Adrien
Publisher: name: figshare
Year: 2023
Subjects: Philosophy of science (excl. history and philosophy of specific fields)
Sociology and social studies of science and technology
History and philosophy of science

description: This is just the introduction of the thesis - Cosmology, the activity of describing the universe’s overall structure and origins, is understood today as the preserve of physics. Physical cosmology is an area of research that has seen such rapid progress in the last decades that it is regarded as the next chapter in physicists’ ambition toward unlocking the secrets of the cosmos and delivering a singular and final account of reality. This thesis argues, however, that rather than a story of linear scientific progress, the becoming scientific of our modern cosmology may be read as the expression of a crisis in fundamental physics, and a sign that its turn towards unity and finality of explanation may be reaching its end, what I call the “end of the universe.” Weaving together the scientific literature, recent historical studies, and philosophical reflection, combined with ethnographic fieldwork and interviews from a sustained engagement with cosmological researchers, I seek to think from this crisis in order to characterise the meaning and purpose of cosmology otherwise. Drawing on the work of William James, Étienne Souriau, Isabelle Stengers, and Alfred North Whitehead, among others, the thesis adopts an empiricist sensibility that explores how the problem of cosmology might be expanded away from a problem of physics to occupy a broader “cosmology of problems.” In this expanded cosmology, exemplified by attending to physicists’ dark matter problem, problems are real, immanent forces that work to form inquirers and the worlds they inhabit. It is this approach – one that seeks to understand how problems come (in)to matter for the peoples, practices, and worlds that belong to them – that I conclude holds promise in the development of a “pluralistic” cosmology. A cosmology that admits a plurality of divergent knowledges and practices into its explanations, ensuring that physicists’ “end of the universe” need not imply the end of their world.
Unique Prediction for High-Energy J/ψPhotoproduction: Color Transparency and Saturation
Creators: name: Schildknecht, Dieter
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Based on the color-dipole picture, we present a successful parameter-free prediction for the recent high-energy $J/ψ$ photoproduction data from the Large Hadron Collider. The experimental data provide empirical evidence for the transition from color transparency to saturation.
description: 10 pages, 4 figures
The turbulence velocity gradient tensor formed additively by normal and non-normal tensors
Creators: name: Keylock, Christopher J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We decompose the velocity gradient tensor for turbulence into normal and non-normal parts, and condition our analysis on the strain eigenvector alignments between these tensors. We identify states that always enhance, and always counteract the axisymmetric expansion state, and give a rationale for decomposing the production balance term into its constituents: complex behavior arises when the dominant strain alignments involve the non-normal tensor. Finally, we develop a topological analysis framework where mathematical bounds on two of the three variables leads to an analysis in two planes.
description: 11 pages, 3 figures
Prediction of a Two-dimensional Sulfur Nitride (S3N2) Solid for Nanoscale Optoelectronic Applications
Creators: name: Xiao, Hang
name: Shi, Xiaoyang
name: Hao, Feng
name: Liao, Xiangbiao
name: Zhang, Yayun
name: Chen, Xi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Two-dimensional materials have attracted tremendous attention for their fascinating electronic, optical, chemical and mechanical properties. However, the band gaps of most 2D materials reported are smaller than 2.0 eV, which greatly restricted their optoelectronic applications in blue and ultraviolet range of the spectrum. Here, we propose a new stable sulfur nitride (S3N2) 2D crystal that is a covalent network composed solely of S-N σ bonds. S3N2 crystal is dynamically stable as confirmed by the computed phonon spectrum and ab initio molecular dynamics simulations in the NPT ensemble. Hybrid density functional calculations show that 2D S3N2 crystal is a wide, direct band-gap (3.17 eV) semiconductor with good hole mobility. These fascinating electronic properties could pave the way for its optoelectronic applications such as blue or ultra-violet light-emitting diodes (LEDs) and photodetectors.
Effect of Densification on Cellular Network Performance with Bounded Pathloss Model
Creators: name: Liu, Junyu
name: Sheng, Min
name: Liu, Lei
name: Li, Jiandong
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In this paper, we investigate how network densification influences the performance of downlink cellular network in terms of coverage probability (CP) and area spectral efficiency (ASE). Instead of the simplified unbounded pathloss model (UPM), we apply a more realistic bounded pathloss model (BPM) to model the decay of signal power caused by pathloss. It is shown that network densification indeed degrades CP when the base station (BS) density $λ$ is sufficiently large. This is inconsistent with the result derived using UPM that CP is independent of $λ$. Moreover, we shed light on the impact of ultra-dense deployment of BSs on the ASE scaling law. Specifically, it is proved that the cellular network ASE scales with rate $λe^{-κλ}$, i.e., first increases with $λ$ and then diminishes to be zero as $λ$ goes to infinity.
description: submitted to IEEE Commun. Lett
Histological and Histochemical Studies on the Esophagus, Stomach and Small Intestines of Vara-nus niloticus
Creators: name: YA, Ahmed
name: AAE, El-Hafez
name: AE, Zayed
Publisher: name: arXiv
Year: 2016
Subjects: subject: Tissues and Organs (q-bio.TO)
subject: FOS: Biological sciences

description: The aim of the current study was to investigate the morphological structure of one of the most common reptilian species in Egypt, Varanus niloticus or Nile monitor. Specimens for histological examination were collected from the esophageus, stomach and small intestine of the Nile monitor and processed for paraffin embedding. Sections were stained with haematoxylin and eosin for general morphology. Periodic Acid Schiff's (PAS) and Alcian Blue (AB) staining methods were applied to detect the different types of the mucous con-tents of the gastro-intestinal tract. Some paraffin sections were stained with Grimelius silver impregnation technique for localization of the enteroendocrine cells. The folded esophageal mucosa had ciliated columnar epithelium with mucous secreting goblet cells, which stained positive with PAS and AB. The esophageal mucosa was folded and the lining epithelium was ciliated columnar epithelium with mucous secreting goblet cells, which stained positive with PAS and AB. The stomach was divided into fundic and pyloric regions. The mucosa was thrown into gastric pits, into which the gastric glands opened. The surface epithelium was mucous secreting columnar cells and stained positive with PAS but negative with AB. The fundic gland was made by oxynticopeptic cells and few mucous cells, while the entire pyloric gland was made by mucous cells stained positive for both PAS and AB. The small intestine showed many villi but occasional poorly developed intestinal crypts were. The intestinal mucosa was lined with absorptive columnar epithelium with goblet cells, which stained positive with PAS and AB. Enteroendocrine cells were of different shapes; rounded, spindle, oval or pyramidal and were localized in the surface epithelium of the esophagus and small intestine, and among the cells of the gastric glands.
description: 19 pages, 4 figures
Unexpected superconductivity at nanoscale junctions made on the topological crystalline insulator Pb$_{0.6}$Sn$_{0.4}$Te
Creators: name: Das, Shekhar
name: Aggarwal, Leena
name: Roychowdhury, Subhajit
name: Aslam, Mohammad
name: Gayen, Sirshendu
name: Biswas, Kanishka
name: Sheet, Goutam
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Discovery of exotic phases of matter from the topologically non-trivial systems not only makes the research on topological materials more interesting but also enriches our understanding of the fascinating physics of such materials. Pb$_{0.6}$Sn$_{0.4}$Te was recently shown to be a topological crystalline insulator. Here we show that by forming a mesoscopic point-contact using a normal non-superconducting elemental metal on the surface of Pb$_{0.6}$Sn$_{0.4}$Te a novel superconducting phase is created locally in a confined region under the point-contact. This happens while the bulk of the sample remains to be non-superconducting and the superconducting phase emerges as a nano-droplet under the point-contact. The superconducting phase shows a high transition temperature $T_c$ that varies for different point-contacts and falls in a range between 3.7 K and 6.5 K. Therefore, this Letter presents the discovery of a new superconducting phase on the surface of a topological crystalline insulator and the discovery is expected to shed light on the mechanism of induced superconductivity in topologically non-trivial systems in general.
description: The submission contains 22 pages including supplementary material. The main text contains 3 figures, 36 references and supplementary material contains 11 figures and one table
Obtaining mass parameters of compact objects from red-blue shifts emitted by geodesic particles around them
Creators: name: Becerril, Ricardo
name: Valdez-Alvarado, Susana
name: Nucamendi, Ulises
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The mass parameters of compact objects such as Boson Stars, Schwarzschild, Reissner Nordstrom and Kerr black holes are computed in terms of the measurable redshift-blueshift (zred, zblue) of photons emitted by particles moving along circular geodesics around these objects and the radius of their orbits. We found bounds for the values of (zred, zblue) that may be observed. For the case of Kerr black hole, recent observational estimates of SrgA\* mass and rotation parameter are employed to determine the corresponding values of these red-blue shifts.
description: 10 pages, 10 figures
The SLUGGS Survey: revisiting the correlation between X-ray luminosity and total mass of massive early-type galaxies
Creators: name: Forbes, Duncan A.
name: Alabi, Adebusola
name: Romanowsky, Aaron J.
name: Kim, Dong-Woo
name: Brodie, Jean P.
name: Fabbiano, Giuseppina
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Here we utilise recent measures of galaxy total dynamical mass and X-ray gas luminosities (L$_{X,Gas}$) for a sample of 29 massive early-type galaxies from the SLUGGS survey to probe L$_{X,Gas}$--mass scaling relations. In particular, we investigate scalings with stellar mass, dynamical mass within 5 effective radii (R$_e$) and total virial mass. We also compare these relations with predictions from $Λ$CDM simulations. We find a strong linear relationship between L$_{X,Gas}$ and galaxy dynamical mass within 5 R$_e$, which is consistent with the recent cosmological simulations of Choi et al. that incorporate mechanical heating from AGN. We conclude that the gas surrounding massive early-type galaxies was shock heated as it fell into collapsing dark matter halos so that L$_{X,Gas}$ is primarily driven by the depth of a galaxy's potential well. Heating by an AGN plays an important secondary role in determining L$_{X,Gas}$.
description: 5 pages, 2 figures, accepted for publication in MNRAS Letters
Equation of state and hybrid star properties with the weakly interacting light U-boson in relativistic models
Creators: name: Zhang, Dong-Rui
name: Jiang, Wei-Zhou
name: Wei, Si-Na
name: Yang, Rong-Yao
name: Xiang, Qian-Fei
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: It has been a puzzle whether quarks may exist in the interior of massive neutron stars, since the hadron-quark phase transition softens the equation of state (EOS) and reduce the neutron star (NS) maximum mass very significantly. In this work, we consider the light U-boson that increases the NS maximum mass appreciably through its weak coupling to fermions. The inclusion of the U-boson may thus allow the existence of the quark degrees of freedom in the interior of large mass neutron stars. Unlike the consequence of the U-boson in hadronic matter, the stiffening role of the U-boson in the hybrid EOS is not sensitive to the choice of the hadron phase models. In addition, we have also investigated the effect of the effective QCD correction on the hybrid EOS. This correction may reduce the coupling strength of the U-boson that is needed to satisfy NS maximum mass constraint. While the inclusion of the U-boson also increases the NS radius significantly, we find that appropriate in-medium effects of the U-boson may reduce the NS radii significantly, satisfying both the NS radius and mass constraints well.
description: 18 pages, 7 figures
A new device-independent dimension witness and its experimental implementation
Creators: name: Cai, Yu
name: Bancal, Jean-Daniel
name: Romero, Jacquiline
name: Scarani, Valerio
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A dimension witness is a criterion that sets a lower bound on the dimension needed to reproduce the observed data. Three types of dimension witnesses can be found in the literature: device-dependent ones, in which the bound is obtained assuming some knowledge on the state and the measurements; device-independent prepare-and-measure ones, that can be applied to any system including classical ones; and device-independent Bell-based ones, that certify the minimal dimension of some entangled systems. Here we consider the Collins-Gisin-Linden-Massar-Popescu (CGLMP) Bell-type inequality for four outcomes. We show that a sufficiently high violation of this inequality witnesses $d \geq 4$ and present a proof-of-principle experimental observation of such a violation. This presents a first experimental violation of the third type of dimension witness beyond qutrits.
description: 4 figures
The Effect of Fiber Collisions on the Galaxy Power Spectrum Multipole
Creators: name: Hahn, ChangHoon
name: Scoccimarro, Roman
name: Blanton, Michael R.
name: Tinker, Jeremy L.
name: Rodriguez-Torres, Sergio
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Fiber-fed multi-object spectroscopic surveys, with their ability to collect an unprecedented number of redshifts, currently dominate large-scale structure studies. However, physical constraints limit these surveys from successfully collecting redshifts from galaxies too close to each other on the focal plane. This ultimately leads to significant systematic effects on galaxy clustering measurements. Using simulated mock catalogs, we demonstrate that fiber collisions have a significant impact on the power spectrum, $P(k)$, monopole and quadrupole that exceeds sample variance at scales smaller than $k\sim0.1~h/Mpc$. We present two methods to account for fiber collisions in the power spectrum. The first, statistically reconstructs the clustering of fiber collided galaxy pairs by modeling the distribution of the line-of-sight displacements between them. It also properly accounts for fiber collisions in the shot-noise correction term of the $P(k)$ estimator. Using this method, we recover the true $P(k)$ monopole of the mock catalogs with residuals of $<0.5\%$ at $k=0.3~h/Mpc$ and $<4\%$ at $k=0.83~h/Mpc$ -- a significant improvement over existing correction methods. The quadrupole, however, does not improve significantly. The second method models the effect of fiber collisions on the power spectrum as a convolution with a configuration space top-hat function that depends on the physical scale of fiber collisions. It directly computes theoretical predictions of the fiber-collided $P(k)$ multipoles and reduces the influence of smaller scales to a set of nuisance parameters. Using this method, we reliably model the effect of fiber collisions on the monopole and quadrupole down to the scale limits of theoretical predictions. The methods we present in this paper will allow us to robustly analyze galaxy power spectrum multipole measurements to much smaller scales than previously possible.
description: 18 pages, 10 figures
Superconductivity in KCa$_2$Fe$_4$As$_4$F$_2$ with Separate Double Fe$_2$As$_2$ Layers
Creators: name: Wang, Zhi-Cheng
name: He, Chao-Yang
name: Wu, Si-Qi
name: Tang, Zhang-Tu
name: Liu, Yi
name: Ablimit, Abduweli
name: Feng, Chun-Mu
name: Cao, Guang-Han
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report synthesis, crystal structure and physical properties of a quinary iron-arsenide fluoride KCa$_2$Fe$_4$As$_4$F$_2$. The new compound crystallizes in a body-centered tetragonal lattice (with space group $I4/mmm$, $a$ = 3.8684(2) Å, c = 31.007(1) Å, and $Z$ = 2), which contains double Fe$_2$As$_2$ conducting layers separated by insulating Ca$_2$F$_2$ layers. Our measurements of electrical resistivity, dc magnetic susceptibility and heat capacity demonstrate bulk superconductivity at 33 K in KCa$_2$Fe$_4$As$_4$F$_2$.
description: 11 pages, 7 figures, 2 tables
Jetted Tidal Disruptions of Stars as a Flag of Intermediate Mass Black Holes at High Redshifts
Creators: name: Fialkov, Anastasia
name: Loeb, Abraham
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Tidal disruption events (TDEs) of stars by single or binary supermassive black holes (SMBHs) brighten galactic nuclei and reveal a population of otherwise dormant black holes. Adopting event rates from the literature, we aim to establish general trends in the redshift evolution of the TDE number counts and their observable signals. We pay particular attention to two types of TDEs which are expected to be observable out to high redshifts, namely (i) jetted TDEs whose luminosity is boosted by relativistic beaming, and (ii) TDEs around binary black holes. We show that the brightest (jetted) TDEs are expected to be produced by massive black hole binaries if the occupancy of intermediate mass black holes (IMBHs) in low mass galaxies is high. The same binary population will also provide gravitational wave sources for eLISA. In addition, we find that the shape of the X-ray luminosity function of TDEs strongly depends on the occupancy of IMBHs and could be used to constrain scenarios of SMBH formation. Finally, we make predictions for the expected number of TDEs observed by future X-ray telescopes as a function of their sensitivity limits. We find that an instrument which is 50 times more sensitive than the Burst Alert Telescope (BAT) on board the Swift satellite is expected to trigger ~10 times more events than BAT with 50% of the events coming from z>2. Because of their long decay times, high-redshift TDEs can be mistaken for fixed point sources in deep field surveys such as the 4Ms survey with the Chandra X-ray Observatory and targeted observations of the same deep field with year-long intervals could reveal TDEs. If the occupation fraction of IMBHs is high, 6-20 TDEs are expected in each deep field observed by a telescope 50 times more sensitive than Chandra.
description: 15 pages, 7 figures, 4 tables
The impact of mass segregation and star-formation on the rates of gravitational-wave sources from extreme mass ratio inspirals
Creators: name: Aharon, Danor
name: Perets, Hagai B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Compact stellar objects inspiralling into massive black holes (MBHs) in galactic nuclei are some of the most promising gravitational wave (GWs) sources for next generation GW-detectors. The rates of such extreme mass ratio inspirals (EMRIs) depend on the dynamics and distribution of compact objects around the MBH. Here we study the impact of mass-segregation processes on EMRI rates. In particular, we provide the expected mass function of EMRIs, given an initial mass function of stellar BHs (SBHs), and relate it to the mass-dependent detection rate of EMRIs. We then consider the role of star formation on the distribution of compact objects and its implication on EMRI rates. We find that the existence of a wide spectrum of SBH masses lead to the overall increase of EMRI rates, and to high rates of the EMRIs from the most-massive SBHs. However, it also leads to a relative quenching of EMRI rates from lower-mass SBHs, and together produces a steep dependence of the EMRI mass function on the highest-mass SBHs. Star-formation history plays a relatively small role in determining the EMRI rates of SBHs, since most of them migrate close to the MBH through mass-segregation rather than forming in-situ. However, the EMRI rate of neutron stars can be significantly increased when they form in-situ close to the MBH, as they can inspiral before relaxation processes significantly segregates them outwards. A reverse but weaker effect of decreasing the EMRI rates from neutron stars and white dwarfs occurs when star-formation proceeds far from the MBH.
description: Submitted to ApJ letters
Gravitational and mass distribution effects on stationary superwinds
Creators: name: Añorve-Zeferino, Gabriel Alejandro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Here, we model the effect of non-uniform dynamical mass distributions and their associated gravitational fields on the stationary galactic superwind solution. We do this by considering an analogue injection of mass and energy from stellar winds and SNe. We consider both compact dark-matter and baryonic haloes that does not extend further from the galaxies optical radii $R_{\rm opt}$ as well as extended gravitationally-interacting ones. We consider halo profiles that emulate the results of recent cosmological simulations and coincide also with observational estimations from galaxy surveys. This allows to compare the analytical superwind solution with outflows from different kinds of galaxies. We give analytical formulae that establish when an outflow is possible and also characterize distinct flow regimes and enrichment scenarios. We also constraint the parameter space by giving approximate limits above which gravitation, self-gravitation and radiative cooling can inhibit the stationary flow. We obtain analytical expressions for the free superwind hydrodynamical profiles. We find that the existence or inhibition of the superwind solution highly depends on the steepness and concentration of the dynamical mass and the mass and energy injection rates. We compare our results with observational data and a recent numerical work. We put our results in the context of the mass-metallicity relationship to discuss observational evidence related to the selective loss of metals from the least massive galaxies and also discuss the case of massive galaxies.
description: Accepted for publications by MNRAS, 2016
When Deep Learning Meets Multi-Task Learning in SAR ATR: Simultaneous Target Recognition and Segmentation
Creators: name: Wang, Chenwei
name: Pei, Jifang
name: Wang, Zhiyong
name: Huang, Yulin
name: Wu, Junjie
name: Yang, Haiguang
name: Yang, Jianyu
Publisher: name: arXiv
Year: 2023
Subjects: subject: Image and Video Processing (eess.IV)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: With the recent advances of deep learning, automatic target recognition (ATR) of synthetic aperture radar (SAR) has achieved superior performance. By not being limited to the target category, the SAR ATR system could benefit from the simultaneous extraction of multifarious target attributes. In this paper, we propose a new multi-task learning approach for SAR ATR, which could obtain the accurate category and precise shape of the targets simultaneously. By introducing deep learning theory into multi-task learning, we first propose a novel multi-task deep learning framework with two main structures: encoder and decoder. The encoder is constructed to extract sufficient image features in different scales for the decoder, while the decoder is a tasks-specific structure which employs these extracted features adaptively and optimally to meet the different feature demands of the recognition and segmentation. Therefore, the proposed framework has the ability to achieve superior recognition and segmentation performance. Based on the Moving and Stationary Target Acquisition and Recognition (MSTAR) dataset, experimental results show the superiority of the proposed framework in terms of recognition and segmentation.
Necessary and Sufficient Condition for Nonsingular Fisher Information Matrix in ARMA Models
Creators: name: McLeod, A. Ian
Publisher: name: arXiv
Year: 2016
Subjects: subject: Applications (stat.AP)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: 62M10, 91B84

description: It is demonstrated that a necessary and sufficient condition that the Fisher information matrix of an ARMA model be nonsingular is that the model not be redundant, that is, the autoregressive and moving-average polynomials do not share common roots.
description: 5 pages
Radiative transfer in disc galaxies $-$ V. The accuracy of the KB approximation
Creators: name: Lee, Dukhang
name: Baes, Maarten
name: Seon, Kwang-Il
name: Camps, Peter
name: Verstocken, Sam
name: Han, Wonyong
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We investigate the accuracy of an approximate radiative transfer technique that was first proposed by Kylafis & Bahcall (hereafter the KB approximation) and has been popular in modelling dusty late-type galaxies. We compare realistic galaxy models calculated with the KB approximation with those of a three-dimensional Monte Carlo radiative transfer code SKIRT. The SKIRT code fully takes into account of the contribution of multiple scattering whereas the KB approximation calculates only single scattered intensity and multiple scattering components are approximated. We find that the KB approximation gives fairly accurate results if optically thin, face-on galaxies are considered. However, for highly inclined ($i \gtrsim 85^{\circ}$) and/or optically thick (central face-on optical depth $\gtrsim1$) galaxy models, the approximation can give rise to substantial errors, sometimes, up to $\gtrsim 40\%$. Moreover, it is also found that the KB approximation is not always physical, sometimes producing infinite intensities at lines of sight with high optical depth in edge-on galaxy models. There is no "simple recipe" to correct the errors of the KB approximation that is universally applicable to any galaxy models. Therefore, it is recommended that the full radiative transfer calculation be used, even though it's slower than the KB approximation.
description: 10 pages, 6 figures, accepted for publication in MNRAS
Clustering sequence data with mixture Markov chains with covariates using multiple simplex constrained optimization routine (MSiCOR)
Creators: name: Das, Priyam
name: Sen, Deborshee
name: De, Debsurya
name: Hou, Jue
name: Abad, Zahra S. H.
name: Kim, Nicole
name: Xia, Zongqi
name: Cai, Tianxi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: Mixture Markov Model (MMM) is a widely used tool to cluster sequences of events coming from a finite state-space. However the MMM likelihood being multi-modal, the challenge remains in its maximization. Although Expectation-Maximization (EM) algorithm remains one of the most popular ways to estimate the MMM parameters, however convergence of EM algorithm is not always guaranteed. Given the computational challenges in maximizing the mixture likelihood on the constrained parameter space, we develop a pattern search-based global optimization technique which can optimize any objective function on a collection of simplexes, which is eventually used to maximize MMM likelihood. This is shown to outperform other related global optimization techniques. In simulation experiments, the proposed method is shown to outperform the expectation-maximization (EM) algorithm in the context of MMM estimation performance. The proposed method is applied to cluster Multiple sclerosis (MS) patients based on their treatment sequences of disease-modifying therapies (DMTs). We also propose a novel method to cluster people with MS based on DMT prescriptions and associated clinical features (covariates) using MMM with covariates. Based on the analysis, we divided MS patients into 3 clusters. Further cluster-specific summaries of relevant covariates indicate patient differences among the clusters.
Determination of the scattering length for Rb-Cs X$^{1}Σ^{+}$ ground electronic state using a variational method
Creators: name: Guimarães, M. N.
name: Prudente, F. V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We performed the calculation of the scattering length for the elastic collision between the rubidium and cesium atoms. For this we applied a variational procedure based on the R-matrix theory for unbound states employing the finite element method (FEM) for expansion of the wave-function in terms of a finite set of local basis functions. The FEM presents as advantages the possibility of the development of a efficient matrix inversion algorithm which significantly reduces the computation time to calculate the R matrix. We also tested a potential energy curve with spectroscopic accuracy obtained before from a direct adjustment procedure of experimental data of the $X^{1}Σ^{+}$ state based on genetic algorithm. The quality of our result was evaluated by comparing them with several ones previously published at literature.
description: 15 pages, 6 tables and 2 figures
Temporal Sentence Grounding in Streaming Videos
Creators: name: Gan, Tian
name: Wang, Xiao
name: Sun, Yan
name: Wu, Jianlong
name: Guo, Qingpei
name: Nie, Liqiang
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Computation and Language (cs.CL)
subject: Multimedia (cs.MM)
subject: FOS: Computer and information sciences

description: This paper aims to tackle a novel task - Temporal Sentence Grounding in Streaming Videos (TSGSV). The goal of TSGSV is to evaluate the relevance between a video stream and a given sentence query. Unlike regular videos, streaming videos are acquired continuously from a particular source, and are always desired to be processed on-the-fly in many applications such as surveillance and live-stream analysis. Thus, TSGSV is challenging since it requires the model to infer without future frames and process long historical frames effectively, which is untouched in the early methods. To specifically address the above challenges, we propose two novel methods: (1) a TwinNet structure that enables the model to learn about upcoming events; and (2) a language-guided feature compressor that eliminates redundant visual frames and reinforces the frames that are relevant to the query. We conduct extensive experiments using ActivityNet Captions, TACoS, and MAD datasets. The results demonstrate the superiority of our proposed methods. A systematic ablation study also confirms their effectiveness.
description: Accepted by ACM MM 2023
Euler systems for GSp(4)
Creators: name: Loeffler, David
name: Skinner, Chris
name: Zerbes, Sarah Livia
Publisher: name: arXiv
Year: 2017
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11F46, 11F67, 11F80, 11R23

description: We construct an Euler system for Galois representations associated to cohomological cuspidal automorphic representations of the group GSp(4), using the pushforwards of Eisenstein classes for GL(2) x GL(2).
description: 41 pages. To appear in "Journal of the European Mathematical Society" (see https://www.ems-ph.org/journals/forthcoming.php?jrn=jems )
Controlling Interface States in 1D Photonic Crystals by tuning Bulk Geometric Phases
Creators: name: Gao, Wensheng
name: Xiao, Meng
name: Chen, Baojie
name: Pun, Edwin Y. B.
name: Chan, C. T.
name: Tam, Wing Yim
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Interface states in photonic crystals usually require defects or surface/interface decorations. We show here that one can control interface states in 1D photonic crystals through the engineering of geometrical phase such that interface states can be guaranteed in even or odd, or in all photonic bandgaps. We verify experimentally the designed interface states in 1D multilayered photonic crystals fabricated by electron beam vapor deposition. We also obtain the geometrical phases by measuring the reflection phases at the bandgaps of the PCs and achieve good agreement with the theory. Our approach could provide a platform for the design of using interface states in photonic crystals for nonlinear optic, sensing, and lasing applications