cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Entanglement of disjoint blocks in the one dimensional Spin 1 VBS
Creators: name: Santos, Raul A.
name: Korepin, Vladimir
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Starting with the valence bond solid (VBS) ground state of the 1D AKLT Hamiltonian, we make a partition of the system in 2 subsystems $A$ and $B$, where $A$ is a block of $L$ consecutive spins and $B$ is it's complement. In that setting we compute the partial transpose density matrix with respect to $A$, $ρ^{T_A}$. We obtain the spectrum of the transposed density matrix of the VBS pure system. Subsequently we define two disjoint blocks, $A$ and $B$ containing $L_A$ and $L_B$ spins respectively, separated by $L$ sites. Tracing away the spins which do not belong to $A\cup B$, we find an expression for the reduced density matrix of the $A$ and $B$ blocks $ρ(A,B)$. With this expression (in the thermodynamic limit), we compute the entanglement spectrum and other several entanglement measures, as the purity $P={\rm tr}(ρ(A,B)^2)$, the negativity $\mathcal{N}$, and the mutual entropy.
description: 28 pages, 4 figures
Planetesimals drifting through dusty and gaseous white dwarf debris discs: Types I, II and III-like migration
Creators: name: Veras, Dimitri
name: Ida, Shigeru
name: Grishin, Evgeni
name: Kenyon, Scott J.
name: Bromley, Benjamin C.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The suite of over 60 known planetary debris discs which orbit white dwarfs, along with detections of multiple minor planets in these systems, motivate investigations about the migration properties of planetesimals embedded within the discs. Here, we determine whether any of the migration regimes which are common in (pre-)main-sequence protoplanetary discs, debris discs and ring systems could be active and important in white dwarf discs. We investigate both dust-dominated and gas-dominated regions, and quantitatively demonstrate that Type I and Type II migration, as well as their particulate disc analogues, are too slow to be relevant in white dwarf discs. However, we find that the analogue of Type III migration for particulate discs may be rapid in the dusty regions of asteroid- or moon-generated ($>10^{18}$ kg) white dwarf discs, where a planetesimal exterior to its Roche radius may migrate across the entire disc within its lifetime. This result holds over a wide range of disc boundaries, both within and exterior to $1R_{\odot}$, and such that the probability of migration occurring increases with higher disc masses.
description: Accepted for publication in MNRAS; corrected typos in Table 1 and References section
Ultrafast measurements in condensed phase systems
Creators: name: Greening, Daniel Benjamin
Publisher: name: Imperial College London
Year: 2019

description: Rapid advances in the field of ultrafast science have led to the creation of isolated attosecond light pulses and pulse trains in the vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) spectral regions. This has opened the possibility for the observation of electronic processes on the attosecond time scale with the technique of attosecond photoelectron spectroscopy. With its expansion to the condensed phase, it allows the investigation of collective electronic processes on atomic length scales with unprecedented time resolution, probing dynamics such as electronic screening, plasmonic excitations and electron transport. An enhanced understanding of these processes is of importance for optoelectronics, catalysis and light harvesting. However, due to both the experimental complexity of such measurements, and the range of possible dynamics occurring simultaneously, isolation of the contribution of a particular dynamical process to the experimental measurement is extremely challenging. New developments in the technique of attosecond photoelectron spectroscopy are therefore required. In this thesis, I describe three developments to the attosecond photoelectron spectroscopy capability. A phase-stable two-colour source was developed, allowing for the possibility of studying the wavelength dependence of the ultrafast field response at the surface. A gas-phase demonstration of the two-colour streaking capability is presented, as well as the creation of XUV attosecond pulses of enhanced flux through a two-colour field synthesis. An experimental scheme for the direct comparison of attosecond valence photoemission from two metal films, Au and Ag, was implemented with experimental results indicating that this scheme can eliminate systematic errors arising from the Gouy phase. Utilizing the capability to produce isolated attosecond pulses at both 20 eV and 93 eV, an experiment investigating VUV-XUV photon energy dependence of attosecond photoemission from Au films is presented. Finally, possibilities for future work utilizing these developments to study the material and wavelength dependence of attosecond photoemission from surfaces are discussed.
Talking Through the Silence: How do Clinical Psychologists Who Have Experienced Suicide Bereavement ‘Make Sense’ of Suicide? - A Thematic Analysis
Creators: name: Salarun, Farahnaaz
Publisher: name: UH Research Archive
Year: 2020
Subjects: clinical psychologist
sense making
suicide
client
friend
family
colleague

description: Aims: From the perspective of an insider researcher, this study focuses on how clinical psychologists make sense of suicide, specifically when they too hold their own personal or professional experiences of suicide bereavement. Method: Twelve semi-structured interviews were carried out with clinical psychologists who had experience of losing a client or a loved one to suicide. The interview data was transcribed verbatim and analysed using Thematic Analysis, according to six-phase framework proposed by Braun and Clarke (2006). Results: Three themes were identified following analysis. The first theme identified was, ‘How talk is experienced as a way of making sense of suicide’, followed by the subthemes ‘Talk as inhibited’, ‘Talk as valued’, and ‘Talk as triggering’. The second theme, “The messiness of being human” was followed by the subthemes, ‘Suicide as the solution’, ‘When views are not aligned’, ‘Walking in the family’s shoes’, ‘The right to live and the right to die’, and ‘Self-doubt – what could I have said or done differently?’. The third and final theme was identified as, ‘An experience that helps clinical psychologists face it’, which was followed by the subthemes ‘Resilience in the face of risk’, ‘Suicide loss shaped career’, and ‘The light within the dark clouds’. Considerations & Implications: This study offers rich insight into an area with limited research. However, it is acknowledged that there is an underrepresentation of participants from diverse backgrounds within the participant sample, and limitations related to the author’s position as an insider researcher. The results from the study have been considered in light of existing theory, and implications for clinical, policy and research domains are discussed.
Bound-free pair production mechanism in Pb-p collisions at LHC
Creators: name: Şengül, Melek Yilmaz
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this work, cross section calculations of bound-free pair production (BFPP) are done for the mechanism in Pb-p collisions at LHC. BFPP cross section for the asymmetric collisions of Pb-p at the center of mass energies of $\sqrt{s_{NN}}=5,02 TeV$ and $\sqrt{s_{NN}}=8,16 TeV$ is computed. In order to reach the exact results, Monte Carlo integration techniques are utilized to calculate the lowest-order Feynman diagrams amplitudes via the lowest order perturbation theory. Also, in this work our cross section results for BFPP mechanism in Pb-p collisions at LHC are compared with BFPP cross section results obtained in literature, which are reached for Pb-p collisions by using a simple scaling applied to scale BFPP cross section results in Pb-Pb collisions at LHC.
On Higgs Decays, Baryon Number Violation, and SUSY at the LHC
Creators: name: Arnold, Jonathan M.
name: Perez, Pavel Fileviez
name: Fornal, Bartosz
name: Spinner, Sogee
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Baryon number violating interactions could modify the signatures of supersymmetric models at the Large Hadron Collider. In this article we investigate the predictions for the Higgs mass and the Higgs decays in a simple extension of the minimal supersymmetric standard model where the local baryon and lepton numbers are spontaneously broken at the TeV scale. This theory predicts baryon number violation at the low scale which can change the current LHC bounds on the supersymmetric spectrum. Using the ATLAS and CMS bounds on the Higgs mass we show the constraints on the sfermion masses, and show the subsequent predictions for the radiative Higgs decays. We found that the Higgs decay into two photons is suppressed due to the existence of new light leptons. In this theory the stops can be very light in agreement with all experimental bounds and we make a brief discussion of the possible signals at the LHC.
The star formation history and metal content of the "Green Peas". New detailed GTC-OSIRIS spectrophotometry of three galaxies
Creators: name: Amorín, Ricardo
name: Pérez-Montero, E.
name: Vílchez, J. M.
name: Papaderos, P.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present deep broad-band imaging and long-slit spectroscopy of three compact, low-mass starburst galaxies at redshift z\sim0.2-0.3, also referred to as Green Peas (GP). We measure physical properties of the ionized gas and derive abundances for several species with high precision. We find that the three GPs display relatively low extinction, low oxygen abundances, and remarkably high N/O ratios We also report on the detection of clear signatures of Wolf-Rayet (WR) stars in these galaxies. We carry out a pilot spectral synthesis study using a combination of both population and evolutionary synthesis models. Their outputs are in qualitative agreement, strongly suggesting a formation history dominated by starbursts. In agreement with the presence of WR stars, these models show that these GPs currently undergo a major starburst producing between ~4% and ~20% of their stellar mass. However, as models imply, they are old galaxies having had formed most of their stellar mass several Gyr ago. The presence of old stars has been spectroscopically verified in one of the galaxies by the detection of Mg I 5167, 5173 absorption line. Additionally, we perform a surface photometry study based on HST data, that indicates that the three galaxies posses an exponential low-surface brightness envelope. If due to stellar emission, the latter is structurally compatible to the evolved hosts of luminous BCD/HII galaxies, suggesting that GPs are identifiable with major episodes in the assembly history of local BCDs. These conclusions highlight the importance of these objects as laboratories for studying galaxy evolution at late cosmic epochs.
description: 30 pages, 9 figures and 7 tables. Accepted for publication in ApJ
On the critical exponent of a quantum noise driven phase transition: the open system Dicke-model
Creators: name: Nagy, D.
name: Szirmai, G.
name: Domokos, P.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: The quantum phase transition of the Dicke-model has been observed recently in a system formed by motional excitations of a laser-driven Bose--Einstein condensate coupled to an optical cavity [1]. The cavity-based system is intrinsically open: photons can leak out of the cavity where they are detected. Even at zero temperature, the continuous weak measurement of the photon number leads to an irreversible dynamics towards a steady-state which exhibits a dynamical quantum phase transition. However, whereas the critical point and the mean field is only slightly modified with respect to the phase transition in the ground state, the entanglement and the critical exponents of the singular quantum correlations are significantly different in the two cases.
description: 7 pages
Data Management Checklist
Creators: name: ETH-Bibliothek
name: Bibliothèque EPFL
Publisher: name: Zenodo
Year: 2016
Subjects: research data
research data management
data management plan
checklist
Switzerland
data life-cycle

description: Managing research data throughout its lifecycle ensures its long-term value and prevents data from falling into digital obsolescence. Proper data management is a key prerequisite for effective data sharing throughout the scientific community. This, in turn, increases the visibility of scholarly work and is likely to increase citation rates. Many funding organizations prescribe the use of data management plans and insist on open access publication of the research results they funded.
 Even if a funding body does not explicitly demand data management, following professional curation and preservation concepts has numerous advantages: It greatly facilitates the reuse of research data. As a result, this increases the impact of research results. It saves precious research funds and ultimately natural and human resources by avoiding unnecessary duplication of work. Today, the availability of well-managed data is part of good scientific practice and ensures the reproducibility of research results, a key requirement at the core of the research process. The following data management checklist is based on a generalised research data lifecycle, and is flexible enough to be applied to requirements from different funding organisations. It is among the first tangible deliverables of the Swiss Data Life-Cycle Management (DLCM) project, facilitated by swissuniversities and involving the collaboration between eight Swiss higher education institutions.
An Algebraic Non-Equilibrium Turbulence Model of the High Reynolds Number Transition Region
Creators: name: Basse, Nils T.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We present a mixing length-based algebraic turbulence model calibrated to pipe flow; the main purpose of the model is to capture the increasing turbulence production-to-dissipation ratio observed in connection with the high Reynolds number transition region. The model includes the mixing length description by Gersten and Herwig, which takes the observed variation of the von Kármán number with Reynolds number into account. Pipe wall roughness effects are included in the model. Results are presented for area-averaged (integral) quantities, which can be used both as a self-contained model and as initial inlet boundary conditions for computational fluid dynamics simulations.
description: 17 pages, 1 table, 10 figures
In search of recognition : environmental change and population displacement
Creators: name: Bumstead, Lysandra S. N.
Publisher: name: University of British Columbia
Year: 2009

description: Twenty-four years have passed since Essam El-Hinnawi of the United Nations Environment Programme warned of a coming crisis of ‘environmental refugees.’ Yet, there is still no international legal framework protecting persons who have been displaced by environmental change. The current and expected exacerbation of climate- and environmental change indicate that environmentally induced displacement may already be occurring. Impoverished persons and states will suffer most, and responses to environmental displacement will largely be determined by states’ capacities for adaptation. Terminological, empirical, and other barriers have prevented the widespread acceptance of the concept of environmental displacement, but suggestions for modifying the existing international refugee regime are problematic. Despite the popularity of the term ‘environmental refugees,’ the majority of environmentally displaced persons in fact remains within their own borders. Thus, a modification of the Guiding Principles on Internal Displacement to acknowledge environmental change as a legitimate cause of human displacement should be applied as a short- to medium-term step toward broader recognition of the emerging issue. The application of the precautionary principle must replace the current business-as-usual attitude of the international community with respect to this emerging issue. The establishment of a proactive international regime to prevent and mitigate environmental displacement, and to offer protection to would-be environmentally displaced persons, will be crucial in sparing as many people as possible from forcible migration. Under a nascent protection regime, those who must move will at least have the legal recognition needed to better meet the challenges of adapting to their new and changing environments.
Probing DDM and ML quantum concepts in shape phase transitions of $γ$-unstable nuclei
Creators: name: Korchi, S. Ait El
name: Chabab, M.
name: Batoul, A. El
name: Lahbas, A.
name: Oulne, M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: In a recent paper (S. Ait El Korchi et al. 2020 EPL 132 52001), we explored, inside the context of Critical Point Symmetries (CPSs) X(3) and Z(4), a correlation between two exceedingly known quantum concepts, the Minimal Length (ML) and the Deformation-Dependent Mass (DDM), that are commonly applied in various areas of physics. Such a correlation has been strongly identified in transition nuclei by calculating some physical observables of that quantum system, like as energy spectra, moments of inertia and transition probabilities. In this paper we extend that study to E(5) dynamical symmetry corresponding to the shape phase transition U(5)$\leftrightarrow$O(6). The experimental realization of the models was found to occur in some nuclei, using the existing phenomenological potentials : Infinite Square Well, Davidson and Kratzer, whose models fits provide the best agreement. Importantly the calculations performed in this work using these potentials corroborate the fact that the revealed correlation between both quantum concepts is not destructively affected by the presence of other model parameters and hence its existence is independent of the form or type of the used potential. Undoubtedly, the present work will open the way for more investigations of this correlation in the limits of other critical points symmetries in nuclear shape phase transitions which play today a major role in nuclear structure research from theoretical as well as experimental point of view.
description: 31 pages, 3 figures, accepted in Nuclear Physics A
Galactic Centre star formation: the case of the missing gas disc
Creators: name: Alexander, R. D.
name: Smedley, S. L.
name: Nayakshin, S.
name: King, A. R.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We study the dynamical evolution of stars and gas close to the centre of the Milky Way. Any plausible means of forming the young stars observed at the Galactic Centre leaves behind a residual gas disc at ~0.01pc radii. We show that the combined effects of viscous accretion and gravitational interactions with stars do not remove the residual gas efficiently, and that a substantial gas disc, interior to the stellar disc, persists for >10Myr after the stars form. Since no such disc is currently seen at the Galactic Centre we argue that it has been accreted by the super-massive black hole. This scenario offers an attractive connection between nuclear star formation and black hole feeding, and we suggest that the "missing" gas may have been used to power Sgr A*.
description: 7 pages, 3 figures. Accepted for publication in MNRAS
Analysis of historic aerial photographs for ecological management using object-based approaches
Creators: name: Morgan, Jessica Lindsay
Publisher: name: University of British Columbia
Year: 2009

description: Aerial photographs are a crucial tool for ecological monitoring and management. New approaches for aerial photograph analysis are needed because of several existing (and anticipated) challenges associated with traditional analysis techniques. The goal of this thesis is to provide a synthesis of the valuable, and often unique, ecological information available from aerial photographs, and to explore the utility of novel image analysis approaches to extract this information. This research is organized to reflect the future of aerial photography as a discipline. In chapter two, I review the benefits and challenges of using aerial photographs for ecological management. The traditional framework used to classify aerial photographs, as well as sources of error are described within the context of the diverse ecological questions that can be addressed using aerial photography. The need for new approaches to analyze aerial photographs is emphasized throughout this chapter. In chapter three, I compare manual interpretation to an automated approach (combining object-based analysis and classification tree modeling), for five classification schemes routinely used in British Columbia. Automated approaches hold potential for replicating certain aspects of the manual process (such as the delineation of polygons), as automated and manually-delineated objects display few statistical differences. Automated classification accuracy is highly variable, with individual class accuracies ranging from 0–74%; however the overall accuracy of several classification schemes exceeded 60%, suggesting certain schemes are well suited to automated analysis. In chapter four, object-based analysis is applied to historic aerial photographs to better quantify spatial heterogeneity, a concept fundamental to the field of landscape ecology. My results suggest sixteen independent factors are needed to describe baseline levels of landscape heterogeneity, including several factors not previously identified by the discipline of landscape ecology. Lastly, in Chapter five, the significance of this thesis for resource management, remote sensing, and landscape ecology is highlighted. Further avenues of research are also discussed.
Multi-Epoch Machine Learning 2: Identifying physical drivers of galaxy properties in simulations
Creators: name: McGibbon, Robert
name: Khochfar, Sadegh
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Using a novel machine learning method, we investigate the buildup of galaxy properties in different simulations, and in various environments within a single simulation. The aim of this work is to show the power of this approach at identifying the physical drivers of galaxy properties within simulations. We compare how the stellar mass is dependent on the value of other galaxy and halo properties at different points in time by examining the feature importance values of a machine learning model. By training the model on IllustrisTNG we show that stars are produced at earlier times in higher density regions of the universe than they are in low density regions. We also apply the technique to the Illustris, EAGLE, and CAMELS simulations. We find that stellar mass is built up in a similar way in EAGLE and IllustrisTNG, but significantly differently in the original Illustris, suggesting that subgrid model physics is more important than the choice of hydrodynamics method. These differences are driven by the efficiency of supernova feedback. Applying principal component analysis to the CAMELS simulations allows us to identify a component associated with the importance of a halo's gravitational potential and another component representing the time at which galaxies form. We discover that the speed of galactic winds is a more critical subgrid parameter than the total energy per unit star formation. Finally we find that the Simba black hole feedback model has a larger effect on galaxy formation than the IllustrisTNG black hole feedback model.
description: 16 pages, 12 figures, accepted to MNRAS
The Relation between Ion Temperature Anisotropy and Formation of Slow Shocks in Collisionless Magnetic Reconnection
Creators: name: Higashimori, Katsuaki
name: Hoshino, Masahiro
Publisher: name: arXiv
Year: 2012
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We perform a two-dimensional simulation by using an electromagnetic hybrid code to study the formation of slow-mode shocks in collisionless magnetic reconnection in low beta plasmas, and we focus on the relation between the formation of slow shocks and the ion temperature anisotropy enhanced at the shock downstream region. It is known that as magnetic reconnection develops, the parallel temperature along the magnetic field becomes large in association with the anisotropic PSBL (plasma sheet boundary layer) ion beams, and this temperature anisotropy has a tendency to suppress the formation of slow shocks. Based on our simulation result, we found that the slow shock formation is suppressed due to the large temperature anisotropy near the X-type region, but the ion temperature anisotropy relaxes with increasing the distance from the magnetic neutral point. As a result, two pairs of current structures, which are the strong evidence of dissipation of magnetic field in slow shocks, are formed at the distance x > 115 ion inertial lengths from the neutral point.
description: 28 pages, 8 figures, accepted for publication in JGR
A Comparison between Digital Image Watermarking in Tow Different Color Spaces Using DWT2
Creators: name: Khalili, Mehdi
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cryptography and Security (cs.CR)
subject: Multimedia (cs.MM)
subject: FOS: Computer and information sciences
subject: D.4.6; K.6.5; K.4.2
subject: 68U10, 68U20, 65C20, 94A08, 94A24, 94A60, 11T71, 14G50, 68P25, 81P94

description: A novel digital watermarking for ownership verification and image authentication applications using discrete wavelet transform (DWT) is proposed in this paper. Most previous proposed watermarking algorithms embed sequences of random numbers as watermarks. Here binary images are taken as watermark for embedding. In the proposed approach, the host image is converted into the YCbCr color space and then its Y channel decomposed into wavelet coefficients. The selected approximation coefficients are quantized and then their four least significant bits of the quantized coefficients are replaced by the watermark using LSB insertion technique. At last, the watermarked image is synthesized from the changed and unchanged DWT coefficients. The experiments show that the proposed approach provides extra imperceptibility and robustness against wavelet compression compared to the traditional embedding methods in RGB color space. Moreover, the proposed approach has no need of the original image to extract watermarks.
description: 5 pages, 4 Figures, 6 Tables. arXiv admin note: text overlap with arXiv:1007.5136 by other authors
Colour jumps across the spiral arms of Hubble Ultra Deep Field galaxies
Creators: name: Martínez-García, Eric E.
name: González-Lópezlira, Rosa A.
name: Puerari, Ivânio
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We have measured, at various wavelengths, the spiral arm pitch angles of a sample of distant spiral galaxies from the Hubble Space Telescope eXtreme Deep Field (XDF). According to density wave theory, we should detect colour jumps from red-to-blue across the spiral arms. Colour jumps are a consequence of large-scale shocks, which also generate the classic blue-to-red age/colour gradients, and have only been detected until now in nearby spiral galaxies. Our results indicate that colour jumps and gradients have been occurring in distant galaxies for at least the last 8 Gyr, in agreement with density wave theory.
description: Accepted for publication in MNRAS
Single-pulse analysis and average emission characteristics of PSR J1820-0427 from observations made with the MWA and uGMRT
Creators: name: Janagal, Parul
name: Chakraborty, Manoneeta
name: Bhat, N. D. Ramesh
name: McSweeney, Samuel J.
name: Sett, Susmita
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We have studied the pulse-to-pulse variability in PSR J1820--0427 and its frequency dependence using high-quality, wide-band observations made from the upgraded Giant Metrewave Radio Telescope (uGMRT; 300-750 MHz) and the Murchison Widefield Array ($\sim$170-200 MHz). The low-frequency data reveal a previously unreported feature in the average profile (at 185 MHz) after accounting for the effects of temporal broadening arising from multi-path scattering due to the Interstellar Medium (ISM). We advance a new method for flux density calibration of beamformed data from the uGMRT and use it to measure the single pulse flux densities across the uGMRT band. Combined with previously published measurements, these flux densities are best fit with a power-law spectrum with a low-frequency turnover. We also use calibrated flux densities to explore the relationship between pulse-to-pulse variability and the spectral index of individual pulses. Our analysis reveals a large scatter in the single-pulse spectral indices and a general tendency for brighter pulses to show a steepening of the spectral index. We also examine the frequency-dependence of the pulse-fluence distribution and its relation to the Stochastic Growth Theory.
description: 13 pages, 9 figures, 2 tables. Accepted for publication in MNRAS
Conformal Phase Transitions at Weak and Strong Coupling
Creators: name: Kutasov, David
name: Lin, Jennifer
name: Parnachev, Andrei
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: D3 and D7-branes intersecting in 2+1 dimensions give rise at low energies to N=4 supersymmetric Yang-Mills theory coupled to defect fermions in the fundamental representation. This theory undergoes a BKT-type phase transition from a conformal phase to one in which the fermions acquire a non-zero mass when the 't Hooft coupling of the N=4 SYM exceeds a critical value. To study this transition, we continue the parameters of the model to a regime where a gravitational description is valid. We use it to calculate the masses of mesons and the phase diagram as a function of temperature and chemical potential. We also comment on the relation of our discussion to the transition from the non-abelian Coulomb phase to a confining one believed to occur in QCD at a critical number of flavors.
description: 52 pages, harvmac; v2: references added
Young Stellar Objects in NGC 6823
Creators: name: Riaz, B.
name: Martin, E. L.
name: Tata, R.
name: Monin, J. -L.
name: Phan-Bao, N.
name: Bouy, H.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: NGC 6823 is a young open cluster that lies at a distance of ~2 kpc in the Vulpecula OB1 association. Previous studies using CCD photometry and spectroscopy have identified a Trapezium system of bright O- and B-type stars at its center. We present optical, near-infrared and Spitzer photometric observations of the cluster. Our survey reaches down to I~22 mag and Ks~18 mag. There is significant differential reddening within the cluster. We find a bimodal distribution for Av, with a peak at ~3 mag and a broader peak at ~10 mag. We find a ~20% fraction of Class I/Class II young stellar objects (YSOs) in the cluster, while a large 80% fraction of the sources have a Class III classification. We have made use of the IPHAS survey in order to probe the strength in Halpha emission for this large population of Class III sources. Nearly all of the Class III objects have photospheric (r'-Halpha) colors, implying an absence of Halpha in emission. This large population of Class III sources is thus likely the extincted field star population rather than the diskless YSOs in the cluster. There is a higher concentration of the Class I/II systems in the eastern region of the cluster and close to the central Trapezium. The western part of the cluster mostly contains Class III/field stars and seems devoid of disk sources. We find evidence of a pre-main sequence population in NGC 6823, in addition to an upper main-sequence population. The pre-main sequence population mainly consists of young disk sources with ages between ~1-5 Myr, and at lower masses of ~0.1-0.4 Msun. There may be a possible mass dependent age spread in the cluster, with the older stars being more massive than the younger ones. The presence of young disk sources in NGC 6823 indicates similar star formation properties in the outer regions of the Galaxy as observed for young clusters in the solar neighborhood.
description: Accepted in MNRAS
The large molecular gas fraction of post-starburst galaxies at z > 1
Creators: name: Zanella, A.
name: Valentino, F.
name: Gallazzi, A.
name: Belli, S.
name: Magdis, G.
name: Bolamperti, A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Post-starburst galaxies are sources that had the last major episode of star formation about 1 Gyr before the epoch of the observations and are on their way to quiescence. It is important to study such galaxies at redshift z > 1, during their main quenching phase, and estimate their molecular gas content to constrain the processes responsible for the cessation of star formation. We present CO(3-2) ALMA observations of two massive (Mstar ~ 5 x 10^10 Msun) post-starburst galaxies at z > 1. We measure their molecular gas fraction to be f_H2 = M_H2/Mstar ~ 8% - 16%, consistent with z < 1 post-starburst galaxies from the literature. The star formation efficiency of our targets is ~ 10x lower than that of star-forming galaxies at similar redshift, and they are outliers of the f_H2 - specific star formation rate (sSFR) relation of star-forming galaxies, as they have larger f_H2 than expected given their sSFR. The gas fraction of post-starbursts from our sample and the literature correlates with the Dn4000 spectral index, a proxy of the stellar population age. This suggests that their gas content decreases after the last major burst of star formation. Finally, one of our targets is undergoing a major merger phase with two highly star-forming companions. This hints at a picture where a perturber event (e.g., major merger) quenches star formation without completely removing the molecular gas.
description: Accepted for publication in MNRAS
Mapping Research Topics on the Net Interest Margin (NIM) Ratio in Sharia and Conventional Banking: VOSviewer Bibliometric Study and Literature Review
Creators: name: Budianto, Eka Wahyu Hestya
name: Dewi, Nindi Dwi Tetria
Publisher: name: Zenodo
Year: 2023

description: This study aims to determine the research mapping regarding the Net Interest Margin (NIM) ratio in Islamic and Conventional Banking using a mix-method approach, namely the VOSviewer bibliometric study and literature review. Data analysis techniques include: (1) mapping the distribution of journal publications around the NIM ratio; (2) mapping the results of the VOSviewer bibliometric visualization around the NIM ratio based on the number of clusters and their items; and (3) mapping research topics around the NIM ratio using a literature review study. The results showed that: (1) based on the distribution of journal publications, there were 216 journal publications regarding the NIM ratio; (2) based on the mapping of the VOSviewer bibliometric study, the network visualization results around the NIM ratio are divided into 5 clusters and 1 73 topic items; (3) based on the mapping of literature review studies, there are 26 topics around the influence of the NIM ratio and 35 topics about the determinants of the NIM ratio. The implications and contributions of this research are to map research topics around NIM ratios in Islamic and Conventional Banking which are often or rarely researched by researchers so that they can be a reference for subsequent researchers.
Coronal activity cycles in nearby G and K stars - XMM-Newton monitoring of 61 Cygni and Alpha Centauri
Creators: name: Robrade, J.
name: Schmitt, J. H. M. M.
name: Favata, F.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We use X-ray observations of the nearby binaries 61 Cyg A/B (K5V and K7V) and Alpha Cen A/B (G2V and K1V) to study the long-term evolution of magnetic activity in weakly to moderately active G + K dwarfs over nearly a decade. Specifically we search for X-ray activity cycles and related coronal changes and compare them to the solar behavior. For 61 Cyg A we find a regular coronal activity cycle analog to its 7.3 yr chromospheric cycle. The X-ray brightness variations are with a factor of three significantly lower than on the Sun, yet the changes of coronal properties resemble the solar behavior with larger variations occurring in the respective hotter plasma components. 61 Cyg B does not show a clear cyclic coronal trend so far, but the X-ray data matches the more irregular chromospheric cycle. Both Alpha Cen stars exhibit significant long-term X-ray variability. Alpha Cen A shows indications for cyclic variability of an order of magnitude with a period of about 12-15 years; the Alpha Cen B data suggests an X-ray cycle with an amplitude of about six to eight and a period of 8-9 years. The sample stars exhibit X-ray luminosities ranging between Lx < 1x10^26 - 3x10^27 erg s^-1 in the 0.2-2.0 keV band and have coronae dominated by cool plasma with variable average temperatures of around 1.0-2.5 MK. We find that coronal activity cycles are apparently a common phenomenon in older, slowly rotating G and K stars. The spectral changes of the coronal X-ray emission over the cycles are solar-like in all studied targets.
description: 11 pages, 9 figures, accepted by Astronomy and Astrophysics
On the Formation of GW190521-like Binary Black Hole Merger Systems
Creators: name: Cui, Zhe
name: Li, Xiang-Dong
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: GW190521 is the most massive merging binary black hole (BBH) system detected so far. At least one of the component BHs was measured to lie within the pair-instability supernova (PISN) mass gap ($\sim 50-135\;{\rm M}_{\odot}$), making its formation a mystery. However, the transient observed signal allows alternative posterior distributions. There was suggestion that GW190521 could be an intermediate-mass ratio inspiral (IMRI), with the component masses $m_1\sim 170\;{\rm M}_{\odot}$ and $m_2\sim 16 \;{\rm M}_{\odot}$, happening to straddle the PISN mass gap. Under this framework, we perform binary population synthesis to explore the formation of GW190521-like systems via isolated binary evolution. We numerically calculate the binding energy parameter for massive stars at different metallicities, and employ them in our calculation for common envelope evolution. Our results prefer that the progenitor binaries formed in metal-poor environment with $\rm Z\leq0.0016$. The predicted merger rate density within redshift $z=1.1$ is $\sim 4\times 10^{-5}-5\times 10^{-2} \,\rm Gpc^{-3}yr^{-1}$. We expect that such events are potentially observable by upcoming both space and ground-based gravitational wave detectors.
description: 20 pages, 9 figures, 8 tables. Accepted by MNRAS
A High-Performance Fortran Code to Calculate Spin- and Parity-Dependent Nuclear Level Densities
Creators: name: Sen'kov, R.
name: Horoi, M.
name: Zelevinsky, V. G.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: A high-performance Fortran code is developed to calculate the spin- and parity-dependent shell model nuclear level densities.The algorithm is based on the extension of methods of statistical spectroscopy and implies exact calculation of the first and second Hamiltonian moments for different configurations at fixed spin and parity. The proton-neutron formalism is used. We have applied the method for calculating the level densities for a set of nuclei in the sd-, pf-, and pf+g9/2 - model spaces. Examples of the calculations for 28Si (in the sd-model space) and 64Ge (in the pf+g9/2-model space) are presented. To illustrate the power of the method we estimate the ground state energy of 64Ge in the larger model space pf+g9/2, which is not accessible to direct shell model diagonalization due to the prohibitively large dimension, by comparing with the nuclear level densities at low excitation energy calculated in the smaller model space pf.
description: 9 pages, 4 figures, 1 table, code description (readme.txt) is attached. arXiv admin note: substantial text overlap with arXiv:1004.5027
A search for charged massive long-lived particles
Creators: name: D0 Collaboration
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2 fb$^{-1}$ of integrated luminosity collected with the D0 detector at the Fermilab Tevatron $p\bar{p}$ collider. We search for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss $(dE/dx)$ inconsistent with muons produced in beam collisions. CMLLPs are predicted in several theories of physics beyond the standard model. We exclude pair-produced long-lived gaugino-like charginos below 267 GeV and higgsino-like charginos below 217 GeV at 95% C.L., as well as long-lived scalar top quarks with mass below 285 GeV.
description: submitted to Phys. Rev. Letters
LABOR EPIDURAL EDUCATION IN THE ANTEPARTUM PERIOD: AN INTERACTIVE COMPUTER-BASED EDUCATION MODULE
Creators: name: Ashlock, Becky Jo
Publisher: name: Zenodo
Year: 2014

description: In the United States, the most common reason for hospital admission is childbirth. Labor epidurals, a form of regional anesthesia, are considered the most effective method of pain relief for laboring women. A trained anesthetist or anesthesiologist must perform the procedure. Prior to any medical procedure, the provider has the obligation to inform the patient of the risks of, benefits of, and alternatives to the procedure. Obtaining consent in the laboring parturient presents several unique challenges. The inability to communicate the required elements of consent to the pregnant woman, with limited English proficiency, presents another challenge for the obstetric anesthesia provider. The literature was reviewed to support the need for antenatal epidural education. Topics searched included the influences of language preference, ethnicity and race on the treatment of pain, and factors influencing the labor epidural consent process and content. The efficacy of multimedia patient education programs was also explored to support the decision to use this format for educating the parturient. The purpose of this project was to create a labor epidural education module in both English and Spanish, which will be available in the antepartum period to improve the consent process. A pilot study to evaluate and compare satisfaction levels with the multimedia platform should be performed prior to widespread implementation among limited English proficiency patients and English language proficient patients. After institutional implementation, a study comparing the time from epidural request to epidural placement between those who iv completed the education module in the antepartum period and those who did not should follow.
Kinematics of an untwisting solar jet in polar coronal hole observed by SDO/AIA
Creators: name: Chen, Huadong
name: Zhang, Jun
name: Ma, Suli
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Using the multi-wavelength data from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) spacecraft, we study a jet occurred in coronal hole near the northern pole of the Sun. The jet presented distinct helical upward motion during ejection. By tracking six identified moving features (MFs) in the jet, we found that the plasma moved at an approximately constant speed along the jet's axis, meanwhile, they made a circular motion in the plane transverse to the axis. Inferred from linear and trigonometric fittings to the axial and transverse heights of the six tracks, the mean values of axial velocities, transverse velocities, angular speeds, rotation periods, and rotation radiuses of the jet are 114 km s$^{-1}$, 136 km s$^{-1}$, 0.81\degr\ s$^{-1}$, 452 s, and 9.8 $\times$ 10$^{3}$ km respectively. As the MFs rose, the jet width at the corresponding height increased. For the first time, we derived the height variation of the longitudinal magnetic field strength in the jet from the assumption of magnetic flux conservation. Our results indicate that, at the heights of 1 $\times$ 10$^{4}$ $\sim$ 7 $\times$ 10$^{4}$ km from jet base, the flux density in the jet decreased from about 15 to 3 G as a function of B=0.5(R/R$_{\sun}$-1)$^{-0.84}$ (G). A comparison was made with the other results in previous studies.
Few simple rules governing hydrogenation of graphene dots
Creators: name: Bonfanti, Matteo
name: Casolo, Simone
name: Tantardini, Gian Franco
name: Ponti, Alessandro
name: Martinazzo, Rocco
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigated binding of hydrogen atoms to small Polycyclic Aromatic Hydrocarbons (PAHs) - i.e. graphene dots with hydrogen-terminated edges - using density functional theory and correlated wavefunction techniques. We considered a number of PAHs with 3 to 7 hexagonal rings and computed binding energies for most of the symmetry unique sites, along with the minimum energy paths for significant cases. The chosen PAHs are small enough to not present radical character at their edges, yet show a clear preference for adsorption at the edge sites which can be attributed to electronic effects. We show how the results, as obtained at different level of theory, can be rationalized in detail with the help of few simple concepts derivable from a tight-binding model of the $π$ electrons.