cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Dynamical He Flashes in Double White Dwarf Binaries
Creators: name: Wong, Tin Long Sunny
name: Bildsten, Lars
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The detonation of an overlying helium layer on a $0.8-1.1\,\mathrm{M}_{\odot}$ carbon-oxygen (CO) white dwarf (WD) can detonate the CO WD and create a thermonuclear supernova (SN). Many authors have recently shown that when the mass of the He layer is low ($\lesssim 0.03\,\mathrm{M}_{\odot}$), the ashes from its detonation minimally impact the spectra and light-curve from the CO detonation, allowing the explosion to appear remarkably similar to Type Ia SNe. These new insights motivate our investigation of dynamical He shell burning, and our search for a binary scenario that stably accumulates thermally unstable He shells in the $0.01-0.08\,\mathrm{M}_{\odot}$ range, thick enough to detonate, but also often thin enough for minimal impact on the observables. We first show that our improved non-adiabatic evolution of convective He shell burning in this shell mass range leads to conditions ripe for a He detonation. We also find that a stable mass-transfer scenario with a high entropy He WD donor of mass $0.15-0.25\,\mathrm{M}_\odot$ yields the He shell masses needed to achieve the double detonations. This scenario also predicts that the surviving He donor leaves with a space velocity consistent with the unusual runaway object, D6-2. We find that hot He WD donors originate in common envelope events when a $1.3-2.0\,\mathrm{M}_\odot$ star fills its Roche lobe at the base of the red giant branch at orbital periods of $1-10$ days with the CO WD.
description: 12 pages, 6 figures; Accepted to ApJ
Nonequilibrium transient dynamics of photon statistics
Creators: name: Ali, Md. Manirul
name: Zhang, Wei-Min
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the transient dynamics of photon statistics through two-time correlation functions for optical fields. We find that the transient correlations at different time t yield a smooth transition from antibunching to bunching photon statistics in the weak system-environment coupling regime. In the strong-coupling regime, the two-time correlations exhibit bunching-antibunching oscillations that persists both in the transient process and in the steady-state limit. The photon bunching-antibunching oscillations is a manifestation of strong non-Markovian dynamics, where the system remains in nonequilibrium from its environment. We also find that the antibunching to bunching transition in the weak-coupling regime and the bunching-antibunching oscillation in the strong-coupling regime are strongly influenced by the initial environment temperature.
description: 5 pages, 3 figures
Domain walls and ferroelectric reversal in corundum derivatives
Creators: name: Ye, Meng
name: Vanderbilt, David
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Domain walls are the topological defects that mediate polarization reversal in ferroelectrics, and they may exhibit quite different geometric and electronic structures compared to the bulk. Therefore, a detailed atomic-scale understanding of the static and dynamic properties of domain walls is of pressing interest. In this work, we use first-principles methods to study the structures of $180^{\circ}$ domain walls, both in their relaxed state and along the ferroelectric reversal pathway, in ferroelectrics belonging to the family of corundum derivatives. Our calculations predict their orientation, formation energy, and migration energy, and also identify important couplings between polarization, magnetization, and chirality at the domain walls. Finally, we point out a strong empirical correlation between the height of the domain-wall mediated polarization reversal barrier and the local bonding environment of the mobile $A$ cations as measured by bond valence sums. Our results thus provide both theoretical and empirical guidance to future searches for ferroelectric candidates in materials of the corundum derivative family.
description: 8 pages, 7 figures
The Most Obscured AGNs in the XMM-SERVS Fields
Creators: name: Yan, Wei
name: Brandt, W. N.
name: Zou, Fan
name: Zhu, Shifu
name: Chen, Chien-Ting J.
name: Hickox, Ryan C.
name: Luo, Bin
name: Ni, Qingling
name: Alexander, David M.
name: Bauer, Franz E.
name: Vignali, Cristian
name: Vito, Fabio
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We perform X-ray spectral analyses to derive characteristics (e.g., column density, X-ray luminosity) of $\approx$10,200 active galactic nuclei (AGNs) in the XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS), which was designed to investigate the growth of supermassive black holes across a wide dynamic range of cosmic environments. Using physical torus models (e.g., Borus02) and a Bayesian approach, we uncover 22 representative Compton-thick (CT; $N_{\rm H} \;>\; 1.5\times10^{24}\; \rm cm^{-2}$) AGN candidates with good signal-to-noise ratios as well as a large sample of 136 heavily obscured AGNs. We also find an increasing CT fraction (\fct ) from low ($z<0.75$) to high ($z>0.75$) redshift. Our CT candidates tend to show hard X-ray spectral shapes and dust extinction in their SED fits, which may shed light on the connection between AGN obscuration and host-galaxy evolution.
description: 12 pages, 9 figures, accepted for publication in ApJ
Search for light curve modulations among Kepler candidates. Three very low-mass transiting companions
Creators: name: Lillo-Box, J.
name: Ribas, A.
name: Barrado, D.
name: Merín, B.
name: Bouy, H.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Light curve modulations in the sample of Kepler planet candidates allows the disentangling of the nature of the transiting object by photometrically measuring its mass. This is possible by detecting the effects of the gravitational pull of the companion (ellipsoidal modulations) and in some cases, the photometric imprints of the Doppler effect when observing in a broad band (Doppler beaming). We aim to photometrically unveil the nature of some transiting objects showing clear modulations in the phase-folded Kepler light curve. We selected a subsample among the large crop of Kepler objects of interest (KOIs) based on their chances to show detectable light curve modulations, i.e., close ($a<12~R_{\star}$) and large (in terms of radius) candidates. We modeled their phase-folded light curves with consistent equations for the three effects, namely, reflection, ellipsoidal and beaming (known as REB modulations). We provide detailed general equations for the fit of the REB modulations for the case of eccentric orbits. These equations are accurate to the photometric precisions achievable by current and forthcoming instruments and space missions. By using this mathematical apparatus, we find three close-in {very low-mass companions (two of them in the brown dwarf mass domain)} orbiting main-sequence stars (KOI-554, KOI-1074, and KOI-3728), and reject the planetary nature of the transiting objects (thus classifying them as false positives). In contrast, the detection of the REB modulations and transit/eclipse signal allows the measurement of their mass and radius that can provide important constraints for modeling their interiors since just a few cases of low-mass eclipsing binaries are known. Additionally, these new systems can help to constrain the similarities in the formation process of the more massive and close-in planets (hot Jupiters), brown dwarfs, and very low-mass companions.
description: Accepted for publication in A&A on May 18th 2016, 9 pages, 5 figures, 4 tables. The first two authors contributed equally to the work contained in this paper
Mechanical dissipation in MoRe superconducting metal drums
Creators: name: Yanai, S.
name: Singh, V.
name: Yuan, M.
name: Gely, M.
name: Bosman, S. J.
name: Steele, G. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We experimentally investigate dissipation in mechanical resonators made of a disordered superconducting thin film of Molybdenum-Rhenium(MoRe) alloy. By electrostatically driving the drum with a resonant AC voltage, we detect its motion using a superconducting microwave cavity. From the temperature dependence of mechanical resonance frequencies and quality factors, we find evidence for non-resonant, mechanically active two-level systems (TLSs) limiting its quality factor at low temperature. In addition, we observe a strong suppression of mechanical dissipation at large mechanical driving amplitudes, suggesting an unconventional saturation of the non-resonant TLSs. These new observations shed light on the mechanism of mechanical damping in superconducting drums and routes towards understanding dissipation in such mechanical systems.
Superluminal light propagation via quantum interference in decay channels
Creators: name: Arun, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We examine the propagation of a weak probe light through a coherently driven $Y$-type system. Under the condition that the excited atomic levels decay via same vacuum modes, the effects of quantum interference in decay channels are considered. It is found that the interference in decay channels results in a lossless anomalous dispersion between two gain peaks. We demonstrate that the probe pulse propagation can in principle be switched from subluminal to superluminal due to the decay-induced interference. We also show that the system exhibits a high index of refraction with negligible absorption for the driving fields. A dressed-state picture of the atom-light interaction is described to explain the numerical results.
description: 9 pages, 8 figures
A 3D physico-chemical model of a pre-stellar core. I. Environmental and structural impact on the distribution of CH$_3$OH and $c$-C$_3$H$_2$
Creators: name: Jensen, S. S.
name: Spezzano, S.
name: Caselli, P.
name: Grassi, T.
name: Haugbølle, T.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Pre-stellar cores represent the earliest stage of the star- and planet-formation process. By characterizing the physical and chemical structure of these cores we can establish the initial conditions for star and planet formation and determine to what degree the chemical composition of pre-stellar cores is inherited to the later stages. A 3D MHD model of a pre-stellar core embedded in a dynamic star-forming cloud is post-processed using sequentially continuum radiative transfer, a gas-grain chemical model, and a line-radiative transfer model. Results are analyzed and compared to observations of CH$_3$OH and $c$-C$_3$H$_2$ in L1544. Nine different chemical models are compared to the observations to determine which initial conditions are compatible with the observed chemical segregation in the prototypical pre-stellar core L1544. The model is able to reproduce several aspects of the observed chemical differentiation in L1544. Extended methanol emission is shifted towards colder and more shielded regions of the core envelope while $c$-C$_3$H$_2$ emission overlaps with the dust continuum, consistent with the observed chemical structure. Increasing the strength of the interstellar radiation field or the cosmic-ray ionization rate with respect to the typical values assumed in nearby star-forming regions leads to synthetic maps that are inconsistent with the observed chemical structure. Our model shows that the observed chemical dichotomy in L1544 can arise as a result of uneven illumination due to the asymmetrical structure of the 3D core and the environment within which the core has formed. This highlights the importance of the 3D structure at the core-cloud transition on the chemistry of pre-stellar cores.
description: Accepted for publication in A&A
Breakup of quantum liquid filaments into droplets
Creators: name: Ancilotto, Francesco
name: Barranco, Manuel
name: Pi, Marti
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We have investigated how the Rayleigh-Plateau instability of a filament made of a 41K-87Rb self-bound mixture may lead to an array of identical quantum droplets, with typical breaking times which are shorter than the lifetime of the mixture. If the filament is laterally confined -- as it happens in a toroidal trap -- and atoms of one species are in excess with respect to the optimal, equilibrium ratio, the droplets are immersed into a superfluid background made by the excess species which provides global phase coherence to the system, suggesting that the droplets array in the unbalanced system may display supersolid character. This possibility has been investigated by computing the non-classical translational inertia coefficient. The filament may be a reasonable representation of a self-bound mixture subject to toroidal confinement when the bigger circle radius of the torus is much larger than the filament radius.
description: 11 pages, 8 figures
Reduced-order particle-in-cell simulations of a high-power magnetically shielded Hall thruster
Creators: name: Reza, Maryam
name: Faraji, Farbod
name: Knoll, Aaron
name: Piragino, Antonio
name: Andreussi, Tommaso
name: Misuri, Tommaso
Publisher: name: arXiv
Year: 2023
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: High-power magnetically shielded Hall thrusters have recently emerged to meet the needs of the next-generation space missions. Even though a few such thrusters are currently undergoing their late-stage development campaigns, many unanswered questions yet exist concerning the behavior and evolution of the plasma in these large-size thrusters that feature an unconventional magnetic field topology. Noting the complex, multi-dimensional nature of plasma processes in Hall thrusters, high-fidelity particle-in-cell simulations are optimal tools to study the intricate plasma behavior. Nonetheless, the significant computational cost of traditional PIC schemes renders simulating high-power thrusters without any physics-altering speed-up factors unfeasible. Thus, in this article, we demonstrate the applicability of the novel reduced-order PIC scheme for a cost-efficient, self-consistent study of the high-power Hall thrusters by performing simulations of a 20 kW magnetically shielded Hall thruster along the axial-azimuthal and radial-azimuthal coordinates. The axial-azimuthal simulations are performed for three operating conditions in a rather simplified representation of the thruster's inherently 3D configuration. Nevertheless, we resolved self-consistently an unprecedented 650 us of the discharge evolution without any ad-hoc electron mobility model, capturing several breathing cycles and approximating the experimental performance parameters with an accuracy of 70 to 80 % across the operating conditions. The radial-azimuthal simulations casted further light on the evolution of the azimuthal instabilities and the resulting variations in the electrons' cross-field mobility and the plasma-wall interactions. Particularly, we observed the development of a long-wavelength, relatively low-frequency wave mode near the exit plane of the thruster's channel that induces a notable electron transport.
description: 29 pages, 25 figures
Perceptually-Driven Video Coding with the Daala Video Codec
Creators: name: Cho, Yushin
name: Daede, Thomas J.
name: Egge, Nathan E.
name: Martres, Guillaume
name: Matthews, Tristan
name: Montgomery, Christopher
name: Terriberry, Timothy B.
name: Valin, Jean-Marc
Publisher: name: arXiv
Year: 2016
Subjects: subject: Multimedia (cs.MM)
subject: FOS: Computer and information sciences

description: The Daala project is a royalty-free video codec that attempts to compete with the best patent-encumbered codecs. Part of our strategy is to replace core tools of traditional video codecs with alternative approaches, many of them designed to take perceptual aspects into account, rather than optimizing for simple metrics like PSNR. This paper documents some of our experiences with these tools, which ones worked and which did not. We evaluate which tools are easy to integrate into a more traditional codec design, and show results in the context of the codec being developed by the Alliance for Open Media.
description: 19 pages, Proceedings of SPIE Workshop on Applications of Digital Image Processing (ADIP), 2016
Spectral density of the Dirac-Ginsparg-Wilson operator, chiral $U(1)_A$ anomaly, and analyticity in the high temperature phase of $QCD$
Creators: name: Azcoiti, Vicente
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Using general properties of the $Q=0$ topological sector we previously argued that a vector-like theory, with chiral $U(1)_A$ anomaly, and exact non-Abelian chiral symmetry, should exhibit divergent susceptibilities in the chiral limit, the two-flavor Schwinger model being a paradigmatic example of the realization of this scenario. Two flavor $QCD$ at $T>T_c$ satisfies all the above conditions, and it is also expected that the $U(1)_A$ axial symmetry remains effectively broken in its high temperature phase. Therefore we would expect a non-analyticity in the quark mass dependence of the free energy density, in contrast with the Dilute Instanton Gas Approximation (DIGA) prediction. We investigate in this work whether the aforementioned results can also be reproduced making only use of standard properties of the spectral density of the Dirac operator, without having to resort to general properties of the $Q=0$ topological sector. We show that the only way to derive a non-trivial $θ$-dependence, and an analytical free energy density in $QCD$ with two degenerate flavors is that the spectral density, $ρ\left(λ,m\right)$, of the absolute value of the non-zero modes of the Dirac-Ginsparg-Wilson operator develops a $m^2δ(λ)$ function in the thermodynamic limit. This is the expected result in the DIGA, where interactions between instantons in the dilute gas are fully neglected. However, at temperatures close to $T_c$ the interaction between instantons should become non-negligible, and the splitting from zero of the near-zero modes, which has been neglected in the DIGA, should be taken into account. Therefore we expect that the $m^2δ(λ)$ contribution to the spectral density is no longer correct at these temperatures, and that the free energy density becomes a non-analytic function of the quark mass.some clarifications added
description: 16 pages, 1 figure; some clarifications added. arXiv admin note: text overlap with arXiv:2101.06439
Observation of a Hidden Hole-Like Band Approaching the Fermi Level in K-Doped Iron Selenide Superconductor
Creators: name: Sunagawa, Masanori
name: Terashima, Kensei
name: Hamada, Takahiro
name: Fujiwara, Hirokazu
name: Fukura, Tetsushi
name: Takeda, Aya
name: Tanaka, Masashi
name: Takeya, Hiroyuki
name: Takano, Yoshihiko
name: Arita, Masashi
name: Shimada, Kenya
name: Namatame, Hirofumi
name: Taniguchi, Masaki
name: Suzuki, Katsuhiro
name: Usui, Hidetomo
name: Kuroki, Kazuhiko
name: Wakita, Takanori
name: Muraoka, Yuji
name: Yokoya, Takayoshi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: One of the ultimate goals of the study of iron-based superconductors is to identify the common feature that produces the high critical temperature (Tc). In the early days, based on a weak-coupling viewpoint, the nesting between hole- and electron-like Fermi surfaces (FSs) leading to the so-called $s\pm$ state was considered to be one such key feature. However, this theory has faced a serious challenge ever since the discovery of alkali-metal-doped FeSe (AFS) superconductors, in which only electron-like FSs with a nodeless superconducting gap are observed. Several theories have been proposed, but a consistent understanding is yet to be achieved. Here we show experimentally that a hole-like band exists in KxFe2-ySe2, which presumably forms a hole-like Fermi surface. The present study suggests that AFS can be categorized in the same group as iron arsenides with both hole- and electron-like FSs present. This result provides a foundation for a comprehensive understanding of the superconductivity in iron-based superconductors.
description: 15 pages, 4 figures, + supplemental material
Effect of non-local transport of hot electrons on the laser-target ablation
Creators: name: Chen, Z. H.
name: Yang, X. H.
name: Zhang, G. B.
name: Ma, Y. Y.
name: Xu, H.
name: Luan, S. X.
name: Zhang, J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The non-local heat transport of hot electrons during high-intensity lasers interaction with plasmas can preheat the fuel and limit the heat flow in inertial confinement fusion. It increases the entropy of the fuel and decreases the final compression. In this paper, the non-local electron transport model that is based on the improved SNB algorithm has been embedded into the radiation hydrodynamic code and is benchmarked with two classical non-local transport cases. Then we studied a 2$ω$ laser ablating a CH target by using the non-local module. It is found that the non-local effect becomes significant when the laser intensity is above $1\times 10^{14} \mathrm{W/cm^{2}} $. The mass ablation rate from the SNB model is increased compared to that of the flux-limited model due to the lower coronal plasma temperature. This non-local model has a better agreement with the experimental results compared to that of the flux-limited model. The non-local transport is strongly dependent on the laser frequency, and the thresholds that the non-local transport should be considered are obtained for lasers of different frequencies. The appropriate flux-limiters that should be employed in the flux-limited model for different lasers are also presented. The results here should have a good reference for the laser-target ablation applications.
description: 8 pages, 9 figures
Energy Cost of Localization of Relational Quantum Information
Creators: name: Dukehart, Adam
name: Mattingly, David
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Entanglement of spatially separated quantum states is usually defined with respect to a reference frame provided by some external observer. Thus, if one wishes to localize the quantum information within a spatially separated entangled state, one must enact an entanglement extraction protocol also defined with respect to that external frame. Entanglement extraction for Gaussian ground states in such an external frame construction has been shown to require a minimum energy and is hence an interesting process for gravitational physics, where examinations of localization vs. energy cost have a long history. General covariance however, precludes dependence on external frames. In order to enact an extraction protocol in a generally covariant theory, dependence on the external reference frame must first be removed and the states made relational. We examine the implementation of an extraction protocol for Gaussian states, who's center-of-mass and relational degrees of freedom are entangled, in a relational toy model where translation invariance stands in for full diffeomorphism invariance. Constructing fully relational states and the corresponding extraction/localization can, in principle, be done in two ways. External frame position information can be removed through $G$-twirling over translations or one can spontaneously break the translation symmetry via the gradient of an auxiliary field, or $Z$-model. We determine the energetics of quantum information localization after the states have been made fully relational via both the $G$-twirl and $Z$-model. We also show one can smoothly transition between the two approaches via positive operator valued measurements (POVM).
description: 15 pages
A QPO in Mkn 421 from Archival RXTE Data
Creators: name: Smith, Evan
name: Oramas, Lani
name: Perlman, Eric
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We report a 325(-7, +8) day quasi-periodic oscillation (QPO) in the X-ray emission of the blazar Mkn 421, based on data obtained with the Rossi X-ray Timing Explorer (RXTE). The QPO is seen prominently in the ASM data (at least 15 cycles), due to the fact that it has had near-continuous sampling for more than a decade. The PCA data, where the sampling is not uniform and shows many large gaps, provide supporting evidence at lower significance. This QPO is present in both the Proportional Counter Array (PCA) and All-Sky Monitor (ASM) light curves, however it is far more secure (32 sigma significance) in the ASM data since much of the PCA data are from target-of-opportunity flare observations and thus have substantial gaps. QPOs are an important observable in accretion disks, can be modulated by various orbital timescales, and may be generated by a number of mechanisms. They have been studied extensively in X-ray binaries, and should be present in active galactic nuclei (AGN) if they are governed by a common set of physical principles. In jetted sources, QPOs can probe jet-disk interactions or helical oscillations. This QPO previously has been claimed intermittently in X-ray, radio and gamma-ray data, but the continuous, 15-year extent (1996-2011) of the ASM observations (in which Mkn 421 is the brightest AGN observed) provides a unique window. The QPO appears present for nearly the entire extent of the ASM observations. We explore various physical origins and modulating mechanisms, particularly interpretations of the QPO as a result of disk-jet interactions, either due to an accretion disk limit cycle, jet instabilities or helical motions. Limit-cycle related oscillations would not interact with either Keplerian or Lense-Thirring modulated oscillations, however those associated with jet instabilities or helical motions in the jet would likely be modulated by Lense-Thirring precession.
description: 10 pages, 8 figures, ApJ, in press
Riemannian Geometry of Two Families of Tangent Lie Groups
Creators: name: Moghaddam, Hamid Reza Salimi
name: Asgari, Farhad
Publisher: name: arXiv
Year: 2016
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53B21, 22E60, 22E15

description: Using vertical and complete lifts, any left invariant Riemannian metric on a Lie group induces a left invariant Riemannian metric on the tangent Lie group. In the present article we study the Riemannian geometry of tangent bundle of two families of Lie groups. The first one is the family of special Lie groups considered by J. Milnor and the second one is the class of Lie groups with one-dimensional commutator groups. The Levi-Civita connection, sectional and Ricci curvatures have been investigated.
Tidal dissipation in stratified and semi-convective regions of giant planets
Creators: name: Pontin, Christina M.
name: Barker, Adrian J.
name: Hollerbach, Rainer
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We study how stably stratified or semi-convective layers alter the tidal dissipation rates associated with the generation of internal waves in planetary interiors. We consider if these layers could contribute to the high rates of tidal dissipation observed for Jupiter and Saturn in our solar system. We use an idealised global spherical Boussinesq model to study the influence of stable stratification and semi-convective layers on tidal dissipation rates. We carry out analytical and numerical calculations considering realistic tidal forcing and measure how the viscous and thermal dissipation rates depend on the parameters relating to the internal stratification profile. We find that the strongly frequency-dependent tidal dissipation rate is highly dependent on the parameters relating to the stable stratification, with strong resonant peaks that align with the internal modes of the system. The locations and sizes of these resonances depend on the form and parameters of the stratification, which we explore both analytically and numerically. Our results suggest that stable stratification can significantly enhance the tidal dissipation in particular frequency ranges. Analytical calculations in the low frequency regime give us scaling laws for the key parameters, including the tidal quality factor $Q'$ due to internal gravity waves. Stably stratified layers can significantly contribute to tidal dissipation in solar and extrasolar giant planets, and we estimate substantial tidal evolution for hot Neptunes. Further investigation is needed to robustly quantify the significance of the contribution in realistic interior models, and to consider the contribution of inertial waves.
description: 29 pages, 17 figures, accepted for publication in ApJ (13th April 2023)
HF trimer: 12D fully coupled quantum calculations of HF-stretch excited intramolecular and intermolecular vibrational states using contracted bases of intramolecular and intermolecular eigenstates
Creators: name: Felker, Peter M.
name: Bačić, Zlatko
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We present the computational methodology which for the first time allows rigorous twelve-dimensional (12D) quantum calculations of the coupled intramolecular and intermolecular vibrational states of hydrogen-bonded trimers of flexible diatomic molecules. Its starting point is the approach that we introduced recently for fully coupled 9D quantum calculations of the intermolecular vibrational states of noncovalently bound trimers comprised of diatomics treated as rigid. In this paper it is extended to include the intramolecular stretching coordinates of the three diatomic monomers. The cornerstone of our 12D methodology is the partitioning of the full vibrational Hamiltonian of the trimer into two reduced-dimension Hamiltonians, one in 9D for the intermolecular degrees of freedom (DOFs) and another in 3D for the intramolecular vibrations of the trimer, and a remainder term. These two Hamiltonians are diagonalized separately and a fraction of their respective 9D and 3D eigenstates is included in the 12D product contracted basis for both the intra- and intermolecular DOFs, in which the matrix of the full 12D vibrational Hamiltonian of the trimer is diagonalized. This methodology is implemented in the 12D quantum calculations of the coupled intra- and intermolecular vibrational states of the hydrogen-bonded HF trimer on an {\it ab initio} calculated potential energy surface (PES). They reveal several interesting manifestations of significant coupling between the intra- and intermolecular vibrational modes of (HF)$_3$. The 12D calculations also show that the frequencies of the $v=1,2$ HF stretching states of HF trimer are strongly redshifted in comparison to those of the isolated HF monomer. The agreement between the 12D results and the limited spectroscopic data for HF trimer, while satisfactory, leaves room for improvement and points to the need for a more accurate PES.
title: Marriage and marriage breakdown in late twentieth-century Scotland
Creators: name: Thomson, Andrea
Publisher: name: University of Glasgow
Year: 2014
Subjects: subject: Marriage, Marriage breakdown, Gender history, Social history, Twentieth century, Scotland

description: Focussing on Scotland, this thesis adds a new perspective to the existing discussion surrounding marriage and marriage breakdown in the late twentieth century. It is the lived reality of marriage and marriage breakdown which is a key focus, using oral history and a range of contemporary and archival source materials. Whilst a renewed discursive emphasis on the 'companionate marriage' in the immediate post-war period is evident, in line with the social reconstruction ethos of the period, there existed alongside such enthusiasm a number of alternative, and often conflicting, contemporary discourses. With significant implications for marriage and family relations, sociologists and historians identify a further profound discursive shift as occurring during the 1970s, emphasising the increased availability of contraception, the emergence of second-wave feminism in Britain and landmark equality legislation as crucial factors intertwined with this. Perceived advances in terms of both mainstream ideology and legislation, including, for example, a revived feminist consciousness and the 1976 Divorce (Scotland) Act, did not influence marriage in a discursive vacuum but instead are likely to have integrated and competed not only with generic ideals regarding appropriate gender roles but also embedded local patterns of gender relations. Oral history is a particularly appropriate methodology with which to address this topic as it permits an otherwise unattainable insight into the experience of day-to-day life. Additional source materials drawn on include parliamentary, ecclesiastical and sociological commentary.
Effect of triangularity on plasma turbulence and the SOL-width scaling in L-mode diverted tokamak configurations
Creators: name: Lim, Kyungtak
name: Giacomin, Maurizio
name: Ricci, Paolo
name: Coelho, António
name: Février, Olivier
name: Mancini, Davide
name: Silvagni, Davide
name: Stenger, Louis
Publisher: name: arXiv
Year: 2023
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The effect of triangularity on tokamak boundary plasma turbulence is investigated by using global, flux-driven, three-dimensional, two-fluid simulations. The simulations show that negative triangularity stabilizes boundary plasma turbulence, and linear investigations reveal that this is due to a reduction of the magnetic curvature drive of interchange instabilities, such as the resistive ballooning mode. As a consequence, the pressure decay length $L_p$, related to the SOL power fall-off length $λ_q$, is found to be affected by triangularity. Leveraging considerations on the effect of triangularity on the linear growth rate and nonlinear evolution of the resistive ballooning mode, the analytical theory-based scaling law for $L_p$ in L-mode plasmas, derived by Giacomin \textit{et al.} [{Nucl. Fusion}, \href{https://doi.org/10.1088/1741-4326/abf8f6}{\textbf{61} 076002} (2021)], is extended to include the effect of triangularity. The scaling is in agreement with nonlinear simulations and a multi-machine experimental database, which include recent TCV discharges dedicated to the study of the effect of triangularity in L-mode diverted discharges. Overall, the present results highlight that negative triangularity narrows the $L_p$ and considering the effect of triangularity is important for a reliable extrapolation of $λ_q$ from present experiments to larger devices.
description: 28 pages, 12 figures, submitted to Plasma Physics and Controlled Fusion
The imprint of hydroclimate, urbanization and catchment connectivity on the stable isotope dynamics of a large river in Berlin, Germany
Creators: name: Kuhlemann, Lena-Marie
name: Tetzlaff, Dörthe
name: Marx, Christian
name: Soulsby, Chris
Publisher: name: Elsevier BV
Year: 2022
Subjects: subject: 500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::551 Geologie, Hydrologie, Meteorologie
subject: urban ecohydrology
subject: stable isotopes
subject: catchment connectivity
subject: drought
subject: urban green spaces
subject: tracers

description: Sustainably meeting the growing water demand of cities during a changing climate will be a major challenge in the near future. Adjusting water management strategies towards preserving urban water resources while best utilizing urban “blue” and “green” infrastructure will require precise knowledge of urban water cycling, storage and losses across large built-up areas. To gain this understanding, using stable isotopes of water as tracers in the hydrological cycle can provide valuable insights, but their application remains challenging in complex and heterogeneous metropolitan areas. This study used stable isotopes, combined with hydrometric and climatic data, to assess the imprint of the urban area and climate warming on a large urbanised river system, the River Spree in Berlin, Germany, during the exceptionally warm and dry 2018 – 2020 period. Isotope dynamics in the Spree reflected gradually varying seasonal patterns with more enriched values in summer and more depleted values in winter. Large-scale climate variability and evaporative losses in the upstream catchment, along with anthropogenic activities, impacted isotope and discharge dynamics in the Spree, especially during warm and dry summer and autumn periods. In local urban sub-catchments, variability of isotope dynamics and subsequent water ages and transit times were largely affected by engineered system components, i.e. catchment imperviousness, connectivity to storm drains and effluent discharge. Berlin’s green spaces were largely disconnected from surface waters. Urban trees in particular had high water demands during dry periods that may be hard to sustain, as trees showed slower replenishment of soil moisture during winter, resulting in shorter recharge periods under trees. More research will be needed on: (a) how planting design with alternations of urban grassland, shrub and trees can enhance infiltration and maintain water demands for trees during drought; and (b) on better quantifying open-water evaporation in the upstream catchment to fully account for catchment water losses. To sustainably manage and preserve not just Berlin’s but also similar cities’ water resources in the future, our results indicate that both integrated city- and catchment-scale measures will be necessary.
CCG workshop - Power and whole energy system modelling - Kenya, October 24th - 28th 2022
Creators: name: Pye, Steve
name: Millot, Ariane
name: Hosseinpoori, Pooya
name: Shivakumar, Abhishek
Publisher: name: Zenodo
Year: 2022

description: This repository contains the material used for the Climate Compatible Growth (CCG) workshop held in Nakuru, Kenya, between October 24th and 28th 2022. The workshop was about capacity training in the use of OSeMOSYS and FlexTool for power sector analysis, and an introduction to the Whole Energy System Model (WESM) for Kenya.
description: This material has been produced with support from the Climate Compatible Growth (CCG) programme. CCG is funded by UK aid from the UK government. Views expressed herein do not necessarily reflect the UK government's official policies
A nonlinear generalization of the Camassa-Holm equation with peakon solutions
Creators: name: Anco, Stephen C.
name: Recio, Elena
name: Gandarias, Maria L.
name: Bruzon, Maria S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Mathematical Physics (math-ph)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: A nonlinearly generalized Camassa-Holm equation, depending an arbitrary nonlinearity power $p \neq 0$, is considered. This equation reduces to the Camassa-Holm equation when $p=1$ and shares one of the Hamiltonian structures of the Camassa-Holm equation. Two main results are obtained. A classification of point symmetries is presented and a peakon solution is derived, for all powers $p \neq 0$.
First computation of Mueller Tang processes using the full NLL BFKL approach
Creators: name: Colferai, Dimitri
name: Deganutti, Federico
name: Raben, Timothy G
name: Royon, Christophe
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present the full next-to-leading order (NLO) prediction for the jet-gap-jet cross section at the LHC within the BFKL approach. We implement, for the first time, the NLO impact factors in the calculation of the cross section. We provide results for differential cross sections as a function of the difference in rapidity and azimuthal angle betwen the two jets and the second leading jet transverse momentum. The NLO corrections of the impact factors induce an overall reduction of the cross section with respect to the corresponding predictions with only LO impact factors. We note that NLO impact factors feature a logarithmic dependence of the cross section on the total center of mass energy which formally violates BFKL factorization. We show that such term is one order of magnitude smaller than the total contribution, and thus can be safely included in the current prediction without a need of further resummation of such logarithmic terms. Fixing the renormalization scale $μ_R$ according to the principle of minimal sensitivity, suggests $μ_R$ about 4 times the sum of the transverse jet energies and provides smaller theroretical uncertainties with respect to the leading order case.
UV Study of the open cluster NGC 2818: Exploring the origins of the exotic stellar populations
Creators: name: Rani, Sharmila
name: Subramaniam, Annapurni
name: Pandey, Gajendra
name: Rao, N. K.
Publisher: name: Zenodo
Year: 2023

description: Star clusters provide the best environment to study the products of binary stellar evolution such as blue straggler stars (BSSs), cataclysmic variables, etc. In this work, we have reported the first far-UV (FUV) photometric results of the detailed study of the exotic stellar populations in the intermediate-age Galactic open cluster NGC2818 that has a planetary nebula (PN) within the field. The observations of this cluster were taken from the Ultra Violet Imaging Telescope (UVIT) onboard AstroSat. We detect four bright and hot BSSs and two yellow straggler stars (YSSs) based on their location in optical and FUV–optical colour–magnitude diagrams. Based on the parameters estimated using spectral energy distributions, we infer that BSSs are either collisional products or might have undetectable white dwarf (WD) companions. Our photometric analysis of YSSs confirms their binarity, consistent with the spectroscopic results.
 We find YSSs to be formed through a mass-transfer scenario and the hot components are likely to be A-type
 subdwarfs. A comparison of the radial velocity, Gaia EDR3 proper motion of the PN with the cluster, and
 reddening toward the PN and the cluster does not rule out the membership of the PN. Comparing the central star’s
 position with theoretical post‐AGB (pAGB) models suggests that it has already entered the WD cooling phase, and
 its mass is deduced to be ∼0.66 Msun. The corresponding progenitor mass turns out to be ∼2.1 Msun, comparable to
 the turn-off mass of the cluster, implying that the progenitor could have formed in the cluster. We suggest that the
 NGC2818 might be one of the few known clusters to host a PN, providing a unique opportunity to test stellar
 evolution models.
Planting a Lyman alpha forest on AbacusSummit
Creators: name: Hadzhiyska, Boryana
name: Font-Ribera, Andreu
name: Cuceu, Andrei
name: Chabanier, Solène
name: Aguilar, Jessica Nicole
name: Brooks, David
name: de la Macorra, Axel
name: Doel, Peter
name: Eisenstein, Daniel J.
name: Forero-Romero, Jaime E.
name: Gontcho, Satya Gontcho A
name: Honscheid, Klaus
name: Kehoe, Robert
name: Landriau, Martin
name: Manera, Marc
name: Miquel, Ramon
name: Nie, Jundan
name: Percival, Will
name: Rossi, Graziano
name: Schubnell, Michael
name: Tarlé, Gregory
name: Zhou, Zhimin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The full-shape correlations of the Lyman alpha (Ly$α$) forest contain a wealth of cosmological information through the Alcock-Paczyński effect. However, these measurements are challenging to model without robustly testing and verifying the theoretical framework used for analyzing them. Here, we leverage the accuracy and volume of the $N$-body simulation suite \textsc{AbacusSummit} to generate high-resolution Ly$α$ skewers and quasi-stellar object (QSO) catalogs. One of the main goals of our mocks is to aid in the full-shape Ly$α$ analysis planned by the Dark Energy Spectroscopic Instrument (DESI) team. We provide optical depth skewers for six of the fiducial cosmology base-resolution simulations ($L_{\rm box} = 2\,h^{-1}{\rm Gpc}$, $N = 6912^3$) at $z = 2.5$. We adopt a simple recipe based on the Fluctuating Gunn-Peterson Approximation (FGPA) for constructing these skewers from the matter density in an $N$-body simulation and calibrate it against the 1D and 3D Ly$α$ power spectra extracted from the hydrodynamical simulation IllustrisTNG (TNG; $L_{\rm box} = 205\,h^{-1}{\rm Mpc}$, $N = 2500^3$). As an important application, we study the non-linear broadening of the baryon acoustic oscillation (BAO) peak and show the cross-correlation between DESI-like QSOs and our Ly$α$ forest skewers. We find differences on small scales between the Kaiser approximation prediction and our mock measurements of the Ly$α$$\times$QSO cross-correlation, which would be important to account for in upcoming analyses. The \textsc{AbacusSummit} Ly$α$ forest mocks open up the possibility for improved modelling of cross correlations between Ly$α$ and cosmic microwave background (CMB) lensing and Ly$α$ and QSOs, and for forecasts of the 3-point Ly$α$ correlation function. Our catalogues and skewers are publicly available on Globus.
description: 17 pages, 8 figures, Globus link: https://app.globus.org/file-manager?origin_id=9ce29982-eed1-11ed-9bb4-c9bb788c490e&path=%2F
A Semantic Analyzer for the Comprehension of the Spontaneous Arabic Speech
Creators: name: Mars, Mourad
name: Zrigui, Mounir
name: Belgacem, Mohamed
name: Zouaghi, Anis
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: This work is part of a large research project entitled "Oréodule" aimed at developing tools for automatic speech recognition, translation, and synthesis for Arabic language. Our attention has mainly been focused on an attempt to improve the probabilistic model on which our semantic decoder is based. To achieve this goal, we have decided to test the influence of the pertinent context use, and of the contextual data integration of different types, on the effectiveness of the semantic decoder. The findings are quite satisfactory.
description: Advances in Computer Science and Engineering. 12 pages 6 figures