cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
One- and two-dimensional hybrid simulations of whistler mode waves in a dipole field
Creators: name: Wu, S
name: Denton, R
name: Liu, K
name: Hudson, M
Publisher: name: Auburn University
Year: 2015

description: We simulate whistler mode waves using a hybrid code. There are four species in the simulations, hot electrons initialized with a bi-Maxwellian distribution with temperature in the direction perpendicular to background magnetic field greater than that in the parallel direction, warm isotropic electrons, cold inertialess fluid electrons, and protons as an immobile background. The density of the hot population is a small fraction of the total plasma density. Comparison between the dispersion relation of our model and other dispersion relations shows that our model is more accurate for lower frequency whistlers than for higher frequency whistlers. Simulations in 2-D Cartesian coordinates agree very well with those using a full dynamics code. In the 1-D simulations along the dipole magnetic field, the predicted frequency and wave number are observed. Rising tones are observed in the one-fourteenth scale simulations that have larger than realistic magnetic field spatial inhomogeneity. However, in the full-scale 1-D simulation in a dipole field, the waves are more broadband and do not exhibit rising tones. In the 2-D simulations in a meridional plane, the waves are generated with propagation approximately parallel to the background magnetic field. However, the wavefronts become oblique as they propagate to higher latitudes. Simulations with different plasma density profiles across L shell are performed to study the effect of the background density on whistler propagation.
Kinetic Alfven Waves From Magnetotail to the Ionosphere in Global Hybrid Simulation Associated With Fast Flows
Creators: name: Cheng, Lei
name: Lin, Yu
name: Perez, J
name: Johnson, Jay
name: Wang, Xueyi
Publisher: name: Auburn University
Year: 2020

description: We have used the Auburn Global Hybrid Code in 3-D to study the generation, dynamics, and global structure of kinetic Alfven waves (KAWs) from the magnetotail to the ionosphere. Our results show that KAWs are generated in magnetic reconnection in the plasma sheet, located around fast flows, and carrying transverse electromagnetic perturbations, parallel Poynting fluxes, parallel currents, and parallel electric field. Overall, shear Alfvenic turbulent spectrum is found in the plasma sheet. The KAWs are shear Alfven waves possessing short perpendicular wavelength with k(perpendicular to)rho(i) similar to 1, where k(perpendicular to) is the perpendicular wave number and rho(i) the ion Larmor radius. The KAWs are identified by their dispersion relation and polarizations. The structures of these KAWs embedded in the plasma sheet are also revealed by placing a virtual satellite in the tail. In order to understand whether the Poynting fluxes carried by the shear Alfven waves/KAWs in the plasma sheet can be carried directly along field lines to the ionosphere, we have tracked the wave propagation from the plasma sheet to the ionosphere. It is found that in front of the flow-braking region, the structure and strength of the shear Alfven waves are significantly altered due to interaction with the dipole-like field, mainly by the flow shear associated with the azimuthal convection. Also in front of the dipole-like field region, ion kinetic effects (Hall effects) lead to the generation of additional pairs of KAWs. As such, the generation and transport of the shear Alfven waves/KAWs to the ionosphere are illustrated for the first time in a comprehensive manner on the global scale.
Searching for degenerate Higgs bosons - A profile likelihood ratio method to test for mass-degenerate states in the presence of incomplete data and uncertainties
Creators: name: David, André
name: Heikkilä, Jaana
name: Petrucciani, Giovanni
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences
subject: G.1.3; G.3
subject: 15A03

description: Using the likelihood ratio test statistic, we present a method which can be employed to test the hypothesis of a single Higgs boson using the matrix of measured signal strengths. This method can be applied in the presence of incomplete data and takes into account uncertainties on the measurements. The p-value against the hypothesis of a single Higgs boson is defined from the expected distribution of the test statistic, generated using pseudo-experiments. The applicability of the likelihood-based test is demonstrated using numerical examples with uncertainties and missing matrix elements.
Quantification of the Atmospheric Relativistic Electron Precipitation on 17 January 2013
Creators: name: Shekhar, S
name: Millan, R
name: Woodger, L
name: Qin, M
Publisher: name: Auburn University
Year: 2020

description: On 17 January 2013, relativistic electron precipitation (REP) was observed on Balloon Array for Radiation Belt Relativistic Electron Losses (BARREL) payloads, National Oceanic and Atmospheric Administration Polar orbiting Operational Environmental Satellites (NOAA POES), and European Space Agency (ESA) MetOp between 2:44 to 15:04 h UT, scattered across dusk to early morning magnetic local time (MLT) sectors. The observations could be grouped into multiple observations of seven REP events spatially separated by more than 2 h in MLT and at least 1 h in UT. Almost all the events were localized in L shell with dL < 0.5 and MLT with dMLT< 3. A net loss of similar to 5% of the relativistic electrons from the radiation belts is estimated between 2:44 to 15:04 h UT (similar to 13.5 h). A majority of atmospheric REP (nearly 75% through six REP events) was observed before the onset of a minor storm around 14:00 UT; the rest (25% through one REP event) was observed during the commencement of the storm which was followed by a major dropout of MeV electrons from the radiation belts during the main phase. However, no atmospheric precipitation was observed during the main phase, indicating that the dropouts may not have been caused by particle loss into the atmosphere.
Postinflationary Higgs relaxation and the origin of matter-antimatter asymmetry
Creators: name: Kusenko, Alexander
name: Pearce, Lauren
name: Yang, Louis
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The recent measurement of the Higgs boson mass implies a relatively slow rise of the Standard Model Higgs potential at large scales, and a possible second minimum at even larger scales. Consequently, the Higgs field may develop a large vacuum expectation value during inflation. The relaxation of the Higgs field from its large postinflationary value to the minimum of the effective potential represents an important stage in the evolution of the universe. During this epoch, the time-dependent Higgs condensate can create an effective chemical potential for the lepton number, leading to a generation of the lepton asymmetry in the presence of some large right-handed Majorana neutrino masses. The electroweak sphalerons redistribute this asymmetry between leptons and baryons. This Higgs relaxation leptogenesis can explain the observed matter-antimatter asymmetry of the universe even if the Standard Model is valid up to the scale of inflation, and any new physics is suppressed by that high scale.
description: 5 pages, 2 figures; accepted for publication in Phys. Rev. Lett
title: Kontext und Symbolik von Schmetterlingsdarstellungen vom Beginn des Alten bis zum Ende des Neuen Reiches
Creators: name: Bsteh, Julian
Year: 2021

description: Das Ziel dieser Masterarbeit war es, den Kontext zu untersuchen, in dem Schmetterlingsdarstellungen in der altägyptischen Kunst auftreten, sowie die Bedeutung dieser Tiere in der Vorstellung der Ägypter so weit wie möglich zu entschlüsseln. Zu diesem Zweck wurden sämtliche verfügbaren überlieferten Schmetterlingsdarstellungen gesammelt, in vier Hauptkategorien unterteilt und im Detail untersucht. Anhand des vorhandenen Materials konnten allgemeine Aussagen zur Ikonographie der Schmetterlinge und ihrer stilistischen Entwicklung getroffen werden. Weiters konnte festgestellt werden, dass die Schmetterlinge primär in einem aquatischen Umfeld dargestellt werden, wobei auch Ausnahmefälle auftreten. Mehrere symbolische Interpretationen wie Sonnen-, Regenerations- und Schutzsymbolik sowie eine potenzielle Verbindung zur Göttin Hathor konnten anhand von Fundkontext, Farb- und Materialsymbolik sowie charakteristischen Merkmalen der Schmetterlinge vorgeschlagen werden. Mangels konkreter schriftlicher Quellen zu den Tieren konnte jedoch keine davon schlüssig belegt werden. Zuletzt musste noch eine bisherige Ansicht zu angeblich schmetterlingsgestaltigen Ideogrammen aus den Pyramidentexten aufgrund ikonographischer Unstimmigkeiten in Frage gestellt werden.
Accelerated Bayesian model-selection and parameter-estimation in continuous gravitational-wave searches with pulsar-timing arrays
Creators: name: Taylor, Stephen
name: Ellis, Justin
name: Gair, Jonathan
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We describe several new techniques which accelerate Bayesian searches for continuous gravitational-wave emission from supermassive black-hole binaries using pulsar timing arrays. These techniques mitigate the problematic increase of search-dimensionality with the size of the pulsar array which arises from having to include an extra parameter per pulsar as the array is expanded. This extra parameter corresponds to searching over the phase of the gravitational-wave as it propagates past each pulsar so that we can coherently include the pulsar-term in our search strategies. Our techniques make the analysis tractable with powerful evidence-evaluation packages like MultiNest. We find good agreement of our techniques with the parameter-estimation and Bayes factor evaluation performed with full signal templates, and conclude that these techniques make excellent first-cut tools for detection and characterisation of continuous gravitational-wave signals with pulsar timing arrays. Crucially, at low to moderate signal-to-noise ratios the factor by which the analysis is sped up can be > 100, permitting rigorous programs of systematic injection and recovery of signals to establish robust detection criteria within a Bayesian formalism.
description: 17 pages, 10 figures, 1 table. Minor changes to reflect published version
Proton velocity ring-driven instabilities in the inner magnetosphere: Linear theory and particle-in-cell simulations
Creators: name: Min, Kyungguk
name: Liu, Kaijun
Publisher: name: Auburn University
Year: 2016

description: Linear dispersion theory and electromagnetic particle-in-cell (PIC) simulations are used to investigate linear growth and nonlinear saturation of the proton velocity ring-driven instabilities, namely, ion Bernstein instability and Alfven-cyclotron instability, which lead to fast magnetosonic waves and electromagnetic ion cyclotron waves in the inner magnetosphere, respectively. The proton velocity distribution is assumed to consist of 10% of a ring distribution and 90% of a low-temperature Maxwellian background. Here two cases with ring speeds v(r)/v(A)=1 and 2 (v(A) is the Alfven speed) are examined in detail. For the two cases, linear theory predicts that the maximum growth rate (m) of the Bernstein instability is 0.16(p) and 0.19(p), respectively, and (m) of the Alfven-cyclotron instability is 0.045(p) and 0.15(p), respectively, where (p) is the proton cyclotron frequency. Two-dimensional PIC simulations are carried out for the two cases to examine the instability development and the corresponding evolution of the particle distributions. Initially, Bernstein waves develop and saturate with strong electrostatic fluctuations. Subsequently, electromagnetic Alfven-cyclotron waves grow and saturate. Despite their smaller growth rate, the saturation levels of the Alfven-cyclotron waves for both cases are larger than those of the Bernstein waves. Resonant interactions with the Bernstein waves lead to scattering of ring protons predominantly along the perpendicular velocity component (toward both decreasing and, at a lesser extent, increasing speeds) without substantial change of either the parallel temperature or the temperature anisotropy. Consequently, the Alfven-cyclotron instability can still grow. Furthermore, the free energy resulting from the pitch angle scattering by the Alfven-cyclotron waves is larger than the free energy resulting from the perpendicular energy scattering, thereby leading to the larger saturation level of the Alfven-cyclotron waves.
Cavity cooling a single charged nanoparticle
Creators: name: Millen, J.
name: Fonseca, P. Z. G.
name: Mavrogordatos, T.
name: Monteiro, T. S.
name: Barker, P. F.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The development of laser cooling coupled with the ability to trap atoms and ions in electromagnetic fields, has revolutionised atomic and optical physics, leading to the development of atomic clocks, high-resolution spectroscopy and applications in quantum simulation and processing. However, complex systems, such as large molecules and nanoparticles, lack the simple internal resonances required for laser cooling. Here we report on a hybrid scheme that uses the external resonance of an optical cavity, combined with radio frequency (RF) fields, to trap and cool a single charged nanoparticle. An RF Paul trap allows confinement in vacuum, avoiding instabilities that arise from optical fields alone, and crucially actively participates in the cooling process. This system offers great promise for cooling and trapping a wide range of complex charged particles with applications in precision force sensing, mass spectrometry, exploration of quantum mechanics at large mass scales and the possibility of creating large quantum superpositions.
description: 8 pages, 5 figures Updated version includes additional references, new title, and supplementary information included
Solution of the equations of motion for a super non-Abelian sigma model in curved background by the super Poisson-Lie T-duality
Creators: name: Eghbali, Ali
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The equations of motion of a super non-Abelian T-dual sigma model on the Lie supergroup $(C^1_1+A)$ in the curved background are explicitly solved by the super Poisson-Lie T-duality. To find the solution of the flat model we use the transformation of supercoordinates, transforming the metric into a constant one, which is shown to be a supercanonical transformation. Then, using the super Poisson-Lie T-duality transformations and the dual decomposition of elements of Drinfel'd superdouble, the solution of the equations of motion for the dual sigma model is obtained. The general form of the dilaton fields satisfying the vanishing $β-$function equations of the sigma models is found. In this respect, conformal invariance of the sigma models built on the Drinfel'd superdouble $((C^1_1+A),I_{(2|2)})$ is guaranteed up to one-loop, at least.
description: 21 pages
New Jersey Alcohol Drug/Drug Resource Center & Clearinghouse Video List
Creators: name: Alcohol Research Documentation, Inc.
Publisher: name: No Publisher Supplied
Year: 2004

description: Copy of the New Jersey Alcohol Drug/Drug Resource Center & Clearinghouse Video Catalog at the Center of Alcohol Studies. Contains over 400 videos related to substance use released in VHS format that used to be available for community users affiliated with any library in New Jersey until 2016. Videos are categorized as Elementary, Secondary, Adult, and Professional. Contains distributors directory and Subject Index.
Three-dimensional global hybrid simulation of dayside dynamics associated with the quasi-parallel bow shock
Creators: name: Lin, Yu
name: Wang, X
Publisher: name: Auburn University
Year: 2005

description: A three-dimensional global-scale hybrid simulation is carried out, for the first time, for dynamics of the dayside bow shock-magnetosphere system associated with the quasi-parallel bow shock. A case with IMF along the Sun-Earth line is examined in detail. First, the foreshock waves and the associated shock reformation process are investigated. In particular, the generation and structure of diamagnetic cavities, with a decrease in the magnetic field and density, in the foreshock of the quasi-parallel shock are discussed. Second, the interaction of the foreshock-originated pressure pulses with the dayside magnetosphere is simulated. The diamagnetic cavities that are generated in the turbulent foreshock due to the ion beam plasma interaction are found to lead to strong surface perturbations at the magnetopause. Third, the coupling between the pressure pulses and the magnetosphere is studied. The compressional waves are found to mode convert to shear Alfven waves and kinetic Alfven waves through the Alfven resonance process in nonuniform plasmas. The shear Alfven waves lead to field line resonance, which corresponds to the fundamental odd resonance wave number, and produce field-aligned currents in the dipole magnetospheric field.
TIME PARTICLES - UNRAVELING THE QUANTUM FABRIC OF REALITY
Creators: name: Brandl, Edenilson
Publisher: name: Zenodo
Year: 2023
Subjects: Time Particles
Quantum Mechanics
Superposition
Time Dilation
Zeitteilchen
Quantenmechanik
Zeitdilatation

description: In this theoretical exploration, we delve into the captivating realm of time particles and their intricate relationship with quantum mechanics. Challenging conventional perceptions of time as a continuous and linear entity, the concept of time particles suggests that time, akin to particles in the quantum world, may exist in discrete, indivisible units. These hypothetical entities, existing in states of superposition, challenge classical notions of time, blurring the distinctions between past, present, and future. This theoretical framework not only pushes the boundaries of our understanding of quantum mechanics but also raises profound philosophical questions about the nature of existence, causality, and consciousness. While the direct empirical evidence for time particles remains elusive, this exploration serves as a catalyst for interdisciplinary research, inspiring scientists, philosophers, and thinkers to contemplate the profound mysteries at the intersection of quantum theory and the philosophy of time.
 
In dieser theoretischen Untersuchung tauchen wir in das faszinierende Reich der Zeitteilchen und ihre komplexe Beziehung zur Quantenmechanik ein. Das Konzept der Zeitteilchen stellt die konventionelle Vorstellung von Zeit als kontinuierlicher und linearer Einheit in Frage und legt nahe, dass Zeit, ähnlich wie Teilchen in der Quantenwelt, in diskreten, unteilbaren Einheiten existieren kann. Diese hypothetischen Entitäten, die in Überlagerungszuständen existieren, stellen klassische Zeitvorstellungen in Frage und verwischen die Grenzen zwischen Vergangenheit, Gegenwart und Zukunft. Dieser theoretische Rahmen verschiebt nicht nur die Grenzen unseres Verständnisses der Quantenmechanik, sondern wirft auch tiefgreifende philosophische Fragen über die Natur der Existenz, der Kausalität und des Bewusstseins auf. Während der direkte empirische Beweis für Zeitteilchen noch schwer fassbar ist, dient diese Untersuchung als Katalysator für interdisziplinäre Forschung und inspiriert Wissenschaftler, Philosophen und Denker, über die tiefgreifenden Geheimnisse an der Schnittstelle von Quantentheorie und Zeitphilosophie nachzudenken.
Manipulation of gap nodes by uniaxial strain in iron-based superconductors
Creators: name: Kang, Jian
name: Kemper, Alexander F.
name: Fernandes, Rafael M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: In the iron pnictides and chalcogenides, multiple orbitals participate in the superconducting state, enabling different gap structures to be realized in distinct materials. Here we argue that the spectral weights of these orbitals can in principle be controlled by a tetragonal symmetry-breaking uniaxial strain, due to the enhanced nematic susceptibility of many iron-based superconductors. By investigating multi-orbital microscopic models in the presence of orbital order, we show that not only $T_{c}$ can be enhanced, but pairs of accidental gap nodes can be annihilated and created in the Fermi surface by an increasing external strain. We explain our results as a mixture of nearly-degenerate superconducting states promoted by strain, and show that the annihilation and creation of nodes can be detected experimentally via anisotropic penetration depth measurements. Our results provide a promising framework to externally control the superconducting properties of iron-based materials.
description: 4 pages + supplementary material, published in in Phys. Rev. Lett
Global Hybrid Simulations of Interaction Between Interplanetary Rotational Discontinuity and Bow Shock/Magnetosphere: Can Ion-Scale Magnetic Reconnection be Driven by Rotational Discontinuity Downstream of Quasi-Parallel Shock?
Creators: name: Guo, Zhifang
name: Lin, Yu
name: Wang, X
Publisher: name: Auburn University
Year: 2021

description: Ion-scale magnetic reconnection has been observed downstream of the terrestrial quasi-parallel (Q-parallel to) shock. Whether it is driven by interplanetary discontinuities or turbulent Q-parallel to shock, however, is unclear. Using three-dimensional global hybrid simulation, we investigate the generation of magnetic reconnection downstream of the Q-parallel to shock, while an interplanetary rotational discontinuity (RD) is launched to the bow shock. Cases with various solar wind Alfven Mach numbers, M-A = 3.0 to 8, and propagation directions of the RD are presented. The propagation direction n is assumed to be in the GSE xz plane and pointing earthward, with n = (-sin(theta(12)/2),0,-cos(theta(12)/2)), where theta(12) is the angle between the upstream (B-1) and downstream (B-2) magnetic fields across the transmitted RD. It is found that magnetic reconnection occurs inside the RD downstream of the Q-parallel to shock, forming flux ropes extending along the dawn-dusk direction about tens of ion inertial lengths. Large-amplitude low-frequency waves originated from the Q-parallel to shock lead to the bending and squeezing of the field lines around the RD, which play an important role in triggering reconnection inside the RD. As the RD impacts the dayside magnetopause, magnetopause reconnection takes place between the field lines behind the RD and geomagnetic field lines. Nevertheless, no reconnection is found downstream of the Q-parallel to shock itself or outside the RD in the magnetosheath. The existent and structure of reconnection in the magnetosheath are found to strongly depend on the parameters M-A and n. Our simulation shows that ion-scale magnetic reconnection is driven by an external driver in the form of the compression of an RD around the bow shock and in the magnetosheath, rather than caused by the turbulent Q-parallel to shock alone.
Vernier caliper and micrometer computer models using Easy Java Simulation and its pedagogical design feature-ideas to augment learning with real instruments
Creators: name: Wee, Loo Kang
name: Ning, Hwee Tiang
Publisher: name: arXiv
Year: 2014
Subjects: subject: Physics Education (physics.ed-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: This article presents the customization of EJS models, used together with actual laboratory instruments, to create an active experiential learning of measurements. The laboratory instruments are the vernier caliper and the micrometer. Three computer model design ideas that complement real equipment are discussed in this article. They are 1) the simple view and associated learning to pen and paper question and the real world, 2) hints, answers, different options of scales and inclusion of zero error and 3) assessment for learning feedback. The initial positive feedback from Singaporean students and educators points to the possibility of these tools being successfully shared and implemented in learning communities, and validated. Educators are encouraged to change the source codes of these computer models to suit their own purposes, licensed creative commons attribution for the benefit of all humankind. Video abstract: http://youtu.be/jHoA5M-_1R4 2015 Resources: http://iwant2study.org/ospsg/index.php/interactive-resources/physics/01-measurements/5-vernier-caliper http://iwant2study.org/ospsg/index.php/interactive-resources/physics/01-measurements/6-micrometer
description: 8 pages, 8 figures, Physics Education journal
A LEAP FROM TRADITION TO MODERNITY; REFLECTED IN "DIFFICULT DAUGHTERS" OF MANJU KAPUR
Creators: name: LINTOMON T A
name: Dr. K. KUMAR
Publisher: name: Zenodo
Year: 2023
Subjects: Feminism, Modernity, Tradition, Women, Education and Society.

description: Abstract  
Literature reflects and presents life in diverse ways, indicating the social status of the people. Feminism is one of the key topics of literature and it tackles a variety of issues concerning women in traditional society. Male chauvinism and inequality discriminated against them for centuries. The shift from Tradition to Modernity is a multidimensional and complex process that has shaped societies all over the world for ages. Manju Kapur's novels are heavily influenced by 'Tradition and Modernity'.   'Difficult Daughters' by Manju Kapur is a remarkable literary lens that examines the tremendous changes from tradition to modernity. Kapur's story expertly depicts the complexities of this cultural transformation, portraying the difficulties, sacrifices and successes that come with the transition from Tradition to Modernity. The story centers around Virmati, a young lady who defies societal norms and expectations in her pursuit of education, freedom and self-discovery. As the novel progresses, Virmati's life symbolizes the turbulent changes that occurred in Indian society throughout the mid-twentieth century. The present paper intends to explore how the characters make their leap from 'Tradition to Modernity.'
Reversal of magnetic field rotation in the reconnection layer due to shear flow effects
Creators: name: Sun, Xiaoxia
name: Lin, Yu
name: Wang, Xiaogang
Publisher: name: Auburn University
Year: 2006

description: We investigate the effects of shear flows on the so-called component reconnection, in which the guide field B-y not equal 0, by solving a one-dimensional Riemann problem for magnetopause reconnection using a resistive MHD simulation. Specifically, we consider the existence of a shear flow perpendicular to the antiparallel magnetic field B-z, while a finite shear flow tangential to B-z may also be present. In the cases without a magnetosheath flow and having thus a sheared flow across the reconnection layer, two time-dependent intermediate shocks TDIS and TDIS' are present on the magnetosheath side and the magnetospheric side, respectively, and the strength of TDIS is much stronger than that of TDIS'. Nevertheless, the existence of the shear flows modifies the structure and strength of the time-dependent intermediate shocks significantly. (1) The perpendicular shear flow V-y0 can lead to the reversal of the rotation sense of the tangential magnetic field in time-dependent intermediate shocks. The critical shear flow speeds, V-c and V-c', for the reversal of field rotations in TDIS and TDIS', respectively, are calculated. (2) For shear flow speed V-y0 = V-c, the strong TDIS is replaced by a steady intermediate shock (IS), whereas at V-y0 = V-c' an Alfven wave pulse is present in the reconnection layer. (3) The presence of tangential shear flow V-z0 alters not only the strength of TDIS and TDIS' but also the critical speeds V-c and V-c'. The critical shear flow speeds obtained from our simulation are found to agree very well with those from the ideal magnetohydrodynamics (MHD), in which the time-dependent intermediate shocks are replaced by rotational discontinuities.
Three-dimensional hybrid simulation of magnetosheath reconnection under northward and southward interplanetary magnetic field
Creators: name: Pang, Y
name: Lin, Y
name: Deng, X
name: Wang, X
name: Tan, B
Publisher: name: Auburn University
Year: 2010

description: A three-dimensional (3-D) global hybrid simulation is carried out for the generation and structure of magnetic reconnection in the magnetosheath because of the interaction of an interplanetary tangential discontinuity (TD) with the bow shock and magnetosphere. Runs are performed for solar wind TDs possessing different polarization senses of magnetic field (north-to-south or south-to-north from the leading to trailing side of the incident TD) and initial half-widths. Two-step compression processes are shown in the transmitted TD, including a shock compression, as the TD passes through the shock followed by a subsequent convective compression while the TD is moving in the magnetosheath toward the magnetopause. In cases with a relatively thin solar wind TD, 3-D patchy reconnection is initiated in the transmitted TD, forming magnetosheath flux ropes. Differences between these flux ropes and those due to magnetopause reconnection are discussed. Multiple components of ion particles are present in the velocity distribution in the magnetosheath merging, accompanied by ion heating. For cases with a relatively wide initial TD, a dominant single X line appears in the subsolar magnetosheath after the transmitted TD is narrowed through the two-step compression process. Specifically, in the cases with a south-to-north field rotation across an incident thin TD, the magnetosheath flux ropes could re-reconnect with the closed geomagnetic field lines to generate a closed field line region with mixed magnetosheath and magnetospheric plasmas, which may contribute to the transport of solar wind plasma into the magnetospheric boundary layer.
Magnetic field rotation and transition width in rotational discontinuities and Alfven wave trains
Creators: name: Lin, Yu
name: Lee, L
Publisher: name: Auburn University
Year: 2000

description: A hybrid simulation is carried out to study the evolution of magnetic field rotations in rotational discontinuities (RDs) and large-amplitude Alfven wave trains (AWTs) whose initial field rotation angle \Delta Phi\ > 180 degrees. For a given initial half width D, the RDs or AWTs lose a multiple of +/-360 degrees field rotation at a critical time, until a smallest rotation angle \Delta Phi\ < 180 degrees is reached. The critical time t(c) for losing the first 360 degrees field rotation is found to be t(c) similar or equal to F(Delta Phi, beta(1), theta(Bn))D3.3+/-0.8, where the function F decreases linearly with Delta Phi, decreases linearly with root beta(1) for upstream ion beta beta(1) > 0.1, and decreases with decreasing shock normal angle theta(Bn). At t < t(c), however, the rotation angle Delta Phi remains unchanged. A search is conducted for minimum widths required for RDs to preserve their \Delta Phi\ > 180 degrees for a given transient convection time at the dayside magnetopause and minimum widths of AWTs per 360 degrees field rotation in the solar wind.
Blast Wave Fits to Elliptic Flow Data at $\sqrt{s_{\rm NN}} =$ 7.7--2760 GeV
Creators: name: Sun, X.
name: Masui, H.
name: Poskanzer, A. M.
name: Schmah, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present blast wave fits to elliptic flow ($v_{2}(p_{\rm T})$) data in minimum bias collisions from the $\sqrt{s_{\rm NN}} =$ 7.7--200 GeV at RHIC, and 2.76 TeV at LHC. The fits are performed separately for particles and corresponding anti-particles. The mean transverse velocity parameter $β$ shows an energy dependent difference between particles and corresponding anti-particles, which increases as the beam energy decreases. Possible effects of feed down, baryon stopping, anti-particle absorption, and early production times for anti-particles are discussed.
description: 7 pages, 4 figures
Scalings of Alfven-cyclotron and ion Bernstein instabilities on temperature anisotropy of a ring-like velocity distribution in the inner magnetosphere
Creators: name: Gary, Peter
name: Min, Kyungguk
name: Liu, Kaijun
Publisher: name: Auburn University
Year: 2016

description: A ring-like proton velocity distribution with f(p)(v)/v>0 and which is sufficiently anisotropic can excite two distinct types of growing modes in the inner magnetosphere: ion Bernstein instabilities with multiple ion cyclotron harmonics and quasi-perpendicular propagation and an Alfven-cyclotron instability at frequencies below the proton cyclotron frequency and quasi-parallel propagation. Recent particle-in-cell simulations have demonstrated that even if the maximum linear growth rate of the latter instability is smaller than the corresponding growth of the former instability, the saturation levels of the fluctuating magnetic fields can be greater for the Alfven-cyclotron instability than for the ion Bernstein instabilities. In this study, linear dispersion theory and two-dimensional particle-in-cell simulations are used to examine scalings of the linear growth rate and saturation level of the two types of growing modes as functions of the temperature anisotropy T/T-parallel to for a general ring-like proton distribution with a fixed ring speed of 2v(A), where v(A) is the Alfven speed. For the proton distribution parameters chosen, the maximum linear theory growth rate of the Alfven-cyclotron waves is smaller than that of the fastest-growing Bernstein mode for the wide range of anisotropies (1T/T-parallel to <= 7) considered here. Yet the corresponding particle-in-cell simulations yield a higher saturation level of the fluctuating magnetic fields for the Alfven-cyclotron instability than for the Bernstein modes as long as T perpendicular to/T-parallel to greater than or similar to. Since fast magnetosonic waves with ion Bernstein instability properties observed in the magnetosphere are often not accompanied by electromagnetic ion cyclotron waves, the results of the present study indicate that the ring-like proton distributions responsible for the excitation of these fast magnetosonic waves should not be very anisotropic.
Temperature-driven crossover in the Lieb-Liniger model
Creators: name: Klumper, Andreas
name: Patu, Ovidiu I.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: The large-distance behavior of the density-density correlation function in the Lieb-Liniger model at finite temperature is investigated by means of the recently derived nonlinear integral equations characterizing the correlation lengths. We present extensive numerical results covering all the physical regimes fromweak to strong interaction and all temperatures. We find that the leading term of the asymptotic expansion becomes oscillatory at a critical temperature which decreases with the strength of the interaction. As we approach the Tonks-Girardeau limit the asymptotic behavior becomes more complex with a double crossover of the largest and next-largest correlation lengths. The crossovers exist only for intermediate couplings and vanish for $γ=0$ and $γ=\infty$.
description: 5 pages, 4 figures, RevTeX 4.1
Viscosity bound for anisotropic superfluids in higher derivative gravity
Creators: name: Bhattacharyya, Arpan
name: Roychowdhury, Dibakar
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: In the present paper, based on the principles of gauge/gravity duality we analytically compute the shear viscosity to entropy ratio corresponding to the superfluid phase in Einstein Gauss-Bonnet gravity. From our analysis we note that the ratio indeed receives a finite temperature correction below certain critical temperature. This proves the non universality of shear viscosity to entropy ratio in higher derivative theories of gravity. We also compute the upper bound for the Gauss-Bonnet coupling corresponding to the symmetry broken phase and note that the upper bound on the coupling does not seem to change as long as we are close to the critical point of the phase diagram. However the corresponding lower bound of the shear viscosity to entropy ratio seems to get modified due to the finite temperature effects.
description: 27 pages; v2: Details added, typos fixed, references updated; version to appear in JHEP
Regime transition of ion Bernstein instability driven by ion shell velocity distributions
Creators: name: Min, Kyungguk
name: Liu, Kaijun
Publisher: name: Auburn University
Year: 2015

description: Linear kinetic dispersion theory is used to investigate a regime transition of the ion Bernstein instability driven by a proton velocity distribution with positive slopes with respect to the perpendicular velocity, f(p)(v(vertical bar)approximate to 0,v)/v>0. The unstable waves arising from this instability are ion Bernstein waves with proton cyclotron harmonic dispersion. However, in the inner magnetosphere, particularly inside of the plasmapause where plasmas are dominated by a cold background, the instability leads to ion Bernstein waves which approximately follow the cold plasma dispersion relation for fast magnetosonic waves and are, therefore, fast magnetosonic-like. Subsequently, the relevant waves have been termed fast magnetosonic waves and many studies have assumed the cold plasma dispersion relation to describe them. On the other hand, how the dispersion properties of ion Bernstein waves become fast magnetosonic-like has not yet been well understood. To examine this regime transition of the instability, we perform linear dispersion analyses using a two-component proton model of f(p)(v) = f(M)(v) + f(s)(v), where f(M) is a Maxwellian velocity distribution and f(s) is an isotropic shell velocity distribution. The results show that the unstable waves are essentially ion Bernstein waves; however, when the shell proton concentration becomes sufficiently small (less than 10), the unstable waves approach the cold plasma dispersion relation for fast magnetosonic waves and become fast magnetosonic-like. Although a reduced proton-to-electron mass ratio of 100 has been used for convenience, which reduces the number of unstable modes involved by lowering the lower hybrid frequency, this does not change the overall regime transition picture revealed in this study.
Fast magnetosonic waves driven by shell velocity distributions
Creators: name: Min, Kyungguk
name: Liu, Kaijun
Publisher: name: Auburn University
Year: 2015

description: Using linear dispersion theory and particle-in-cell simulations, we explore the ion Bernstein instability driven by the shell-type ion velocity distribution which is related to the excitation of fast magnetosonic waves in the terrestrial magnetosphere. We first demonstrate a novel idea to construct the shell velocity distribution out of multiple Maxwellian ring-beam velocity distributions. Applying this technique, we find that the convergence of the linear theory instability can be achieved with only a moderate number of ring-beam components. In order to prove that such an approximation is legitimate and the linear theory instabilities evaluated are indeed valid, we use the exact shell distribution to carry out a number of one dimensional particle-in-cell simulations corresponding to multiple wave propagation angles adjacent to the direction at which the most unstable waves are expected to grow. The agreement between the linear dispersion analysis and the simulation results is generally very good: enhanced waves are organized along the linear theory dispersion curves in the frequency-wave number space, and relative wave amplitudes are ordered as the linear theory growth rates very well. However, the simulations show a few extra branches that are not expected from the linear dispersion analysis. A close examination of these extra branches suggests that they are not simulation artifacts and particularly related to the ring/shell-type distributions with large ring/shell speed (v>approximate to 1.5 v(A), where v(A) is the Alfven speed). In addition, our results show that substantial wave growth can occur at nonintegral harmonics of the proton cyclotron frequency at wave normal angles substantially far away from the perpendicular direction, which may provide an alternative explanation of the off-harmonic peaks of some fast magnetosonic waves observed in space.
Investigation of storm timemagnetotail and ion injection using three-dimensional global hybrid simulation
Creators: name: Lin, Y
name: Wang, X
name: Lu, S
name: Perez, J
name: Lu, Q
Publisher: name: Auburn University
Year: 2014

description: Dynamics of the near-Earth magnetotail associated with substorms during a period of extended southward interplanetary magnetic field is studied using a three-dimensional (3-D) global hybrid simulation model that includes both the dayside and nightside magnetosphere, for the first time, with physics from the ion kinetic to the global Alfvenic convection scales. It is found that the dayside reconnection leads to the penetration of the dawn-dusk electric field through the magnetopause and thus a thinning of the plasma sheet, followed by the magnetotail reconnection with 3-D, multiple flux ropes. Ion kinetic physics is found to play important roles in the magnetotail dynamics, which leads to the following results: (1) Hall electric fields in the thin current layer cause a systematic dawnward ion drift motion and thus a dawn-dusk asymmetry of the plasma sheet with a higher (lower) density on the dawnside (duskside). Correspondingly, more reconnection occurs on the duskside. Bidirectional fast ions are generated due to acceleration in reconnection, and more high-speed earthward flow injections are found on the duskside than the dawnside. Such finding of the dawn-dusk asymmetry is consistent with recent satellite observations. (2) The injected ions undergo the magnetic gradient and curvature drift in the dipole-like field, forming a ring current. (3) Ion particle distributions reveal multiple populations/beams at various distances in the tail. (4) Dipolarization of the tail magnetic field takes place due to the pileup of the injected magnetic fluxes and thermal pressure of injected ions, where the fast earthward flow is stopped. Oscillation of the dipolarization front is developed at the fast-flow braking, predominantly on the dawnside. (5) Kinetic compressional wave turbulence is present around the dipolarization front. The cross-tail currents break into small-scale structures with where is the perpendicular wave number. A sharp dip of magnetic field strength is seen just in front of the sharp rise of the magnetic field at the dipolarization front, mainly on the duskside. (6) A shear flow-type instability is found on the duskside flank of the ring current plasma, whereas a kinetic ballooning instability appears on the dawnside. (7) Shear Alfvenic waves and compressional waves are generated from the tail reconnection, and they evolve into kinetic Alfvn waves in the dipole-like field region. Correspondingly, multiple field-aligned current filaments are generated above the auroral ionosphere.
Halpha emission-line stars in molecular clouds. II. The M42 region
Creators: name: Pettersson, Bertil
name: Armond, Tina
name: Reipurth, Bo
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present a deep survey of Halpha emission-line stars in the M42 region using wide-field objective prism films. A total of 1699 Halpha emission-line stars were identified, of which 1025 were previously unknown, within an area of 5.5 x 5.5 degrees centred on the Trapezium Cluster. We present Halpha strength estimates, positions, and JHKs photometry extracted from 2MASS, and comparisons to previous surveys. The spatial distribution of the bulk of the stars follows the molecular cloud as seen in CO and these stars are likely to belong to the very young population of stars associated with the Orion Nebula Cluster. Additionally, there is a scattered population of Halpha emission-line stars distributed all over the region surveyed, which may consist partly of foreground stars associated with the young NGC 1980 cluster, as well as some foreground and background dMe or Be stars. The present catalogue adds a large number of candidate low-mass young stars belonging to the Orion population, selected independently of their infrared excess or X-ray emission.
description: 38 pages, 18 figures. Published in Astronomy & Astrophysics v3: chart for ESO-HA 1639 corrected. Typos in Table 2 corrected. Photometry for ESO-HA 1639 in Table 2 corrected
ISOLATION AND CHARACTERIZATION OF NITROGEN AND INDOLE ACETIC ACID PRODUCING RHIZOBACTERIA FROM LOCAL UPLAND RICE PLANTS IN SOUTH SULAWESI, INDONESIA
Creators: name: SITTI MARYAM YASIN
name: ELKAWAKIB SYAM'UM
name: BURHANUDDIN RASYID
name: AMIR YASSI
Publisher: name: Zenodo
Year: 2023
Subjects: Indole Acetic Acid; Nitrogen; Rhizobacteria; Rice

description: Abstract
This study aimed to determine the type of isolate and the characteristics of nitrogen fixing bacteria in the rhizosphere of local organic upland rice in the highlands. This research was conducted in North Luwu Regency, South Sulawesi, Indonesia and the Pest Science Laboratory, Department of Plant Pests and Diseases, Hasanuddin University. The research method was a descriptive study using morphological and physiological characterization (Gram reaction test using 3% KOH), nitrogen fixation ability test of bacteria and Indole Acetic Acid (IAA) production test. Morphological characterization of nitrogen fixing bacterial isolates from local organic rice rhizospheres showed 5 of the tarone variety and 7 of the local rice tarone hoyane variety from Seko Subdistrict. The results of the morphological characterization showed different results in terms of color, size, shape and level. Nitrogen fixation ability test of the isolate from the rhizosphere of the local rice tarone hoyane variety achieved the highest nitrogen binding ability (2.082), Seko Subdistrict (962), Rongkong Subdistrict (996), and the lowest was the isolate from the banjara rice variety (707). The ability test of IAA production of the local upland rice rhizosphere bacterial isolates of the tarone hoyane rice variety produced a more intense pink color and had the highest concentration of IAA (1.835 mg L-1), Seko Subdistrict (1.630 mg L-1), and Rongkong Subdistrict (1,566 mg L-1). Meanwhile, the bacterial isolate of the local rice banjara variety from Rongkong Subdistrict obtained the lowest IAA (0.316 mg L-1).