cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
In-situ star formation in accretion disk and explanation for correlation between black hole mass and metallicity in AGNs
Creators: name: Fan, Xiao
name: Wu, Qingwen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Recent observations show that the metallicity of the broad line region ($Z_{\rm BLR}$) in active galactic nuclei (AGNs) is solar-to-supersolar, which is positively correlated with the mass of supermassive black holes ($M_{\rm BH}$) and does not evolve with redshift up to $z \sim 7$. We revisit the $M_{\rm BH}-Z_{\rm BLR}$ correlation with more AGNs with $M_{\rm BH}\sim 10^{6-8} M_{\odot}$ and find that the positive correlation become flat in low-mass range. It is known that outer part of accretion disks is gravitationally unstable and can fragment into stars. Considering the star formation and supernovae (SNe) in the outer AGN disk, we calculate the metal enrichment and find that positive $M_{\rm BH}-Z_{\rm BLR}$ correlation can be roughly reproduced if the stellar mass distribution is ``top-heavy". We find that the observed BLR size is more or less similar to the self-gravity radius of the AGN disk, which suggests that the BLR may be closely correlated with the underlying accretion process.
description: 17 pages, 6 figures, 1 table. Accepted for publication in ApJ
A transmission problem for quasi-linear wave equations
Creators: name: Andersson, Lars
name: Oliynyk, Todd A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We prove the local existence and uniqueness of solutions to a system of quasi-linear wave equations involving a jump discontinuity in the lower order terms. A continuation principle is also established.
description: The results of this article are essential to a local existence proof of solutions to the Einstein field equations coupled to elastic matter that represent gravitating compact bodies. The full existence proof will be presented in a separate article
Absolute Properties of the Eclipsing Binary Star AP Andromedae
Creators: name: Lacy, Claud H. Sandberg
name: Torres, Guillermo
name: Fekel, Francis C.
name: Muterspaugh, Matthew W.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: AP And is a well-detached F5 eclipsing binary star for which only a very limited amount of information was available before this publication. We have obtained very extensive measurements of the light curve (19097 differential V magnitude observations) and a radial velocity curve (83 spectroscopic observations) which allow us to fit orbits and determine the absolute properties of the components very accurately: masses of 1.277 +/- 0.004 and 1.251 +/- 0.004 solar masses, radii of 1.233 +/- 0.006 and 1.1953 +/- 0.005 solar radii, and temperatures of 6565 +/- 150 K and 6495 +/- 150 K. The distance to the system is about 400 +/- 30 pc. Comparison with the theoretical properties of the stellar evolutionary models of the Yonsei-Yale series of Yi et al. shows good agreement between the observations and the theory at an age of about 500 Myr and a slightly sub-solar metallicity.
Fastlim: a fast LHC limit calculator
Creators: name: Papucci, Michele
name: Sakurai, Kazuki
name: Weiler, Andreas
name: Zeune, Lisa
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Fastlim is a tool to calculate conservative limits on extensions of the Standard Model from direct LHC searches without performing any Monte Carlo event generation. The program reconstructs the visible cross sections from pre-calculated efficiency tables and cross section tables for simplified event topologies. As a proof of concept of the approach, we have implemented searches relevant for supersymmetric models with R-parity conservation. Fastlim takes the spectrum and coupling information of a given model point and provides, for each signal region of the implemented analyses, the visible cross sections normalised to the corresponding upper limit, reported by the experiments, as well as the exclusion $p$-value. To demonstrate the utility of the program we study the sensitivity of the recent ATLAS missing energy searches to the parameter space of natural SUSY models. The program structure allows the straight-forward inclusion of external efficiency tables and can be generalised to R-parity violating scenarios and non-SUSY models. This paper serves as a self-contained user guide, and indicates the conventions and approximations used.
description: 39 pages, 43 figures
Comparison of dynamical and kinematic reference frames via pulsar positions from timing, Gaia, and interferometric astrometry
Creators: name: Liu, Niu
name: Zhu, Zi
name: Antoniadis, John
name: Liu, Jia-Cheng
name: Zhang, Hong
name: Jiang, Nan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Pulsars are special objects whose positions can be determined independently from timing, radio interferometric, and Gaia astrometry at sub-milliarcsecond (mas) precision; thus, they provide a unique way to monitor the link between dynamical and kinematic reference frames. We aimed to assess the orientation consistency between the dynamical reference frame represented by the planetary ephemeris and the kinematic reference frames constructed by Gaia and VLBI through pulsar positions. We identified 49 pulsars in Gaia Data Release 3 and 62 pulsars with very long baseline interferometry (VLBI) positions from the PSR$π$ and MSPSR$π$ projects and searched for the published timing solutions of these pulsars. We then compared pulsar positions measured by timing, VLBI, and Gaia to estimate the orientation offsets of the ephemeris frames with respect to the Gaia and VLBI reference frames by iterative fitting. We found orientation offsets of $\sim$10 mas in the DE200 frame with respect to the Gaia and VLBI frame. Our results depend strongly on the subset used in the comparison and could be biased by underestimated errors in the archival timing data, reflecting the limitation of using the literature timing solutions to determine the frame rotation.
description: 22 pages, 15 figures, 3 tables, accepted for publication at A&A
On an Algorithm for Obtaining All Binary Matrices of Special Class Related to V. E. Tarakanov's Formula
Creators: name: Yordzhev, Krasimir
Publisher: name: arXiv
Year: 2013
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: Combinatorics (math.CO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: 05B20

description: An algorithm for obtaining all n\times n binary matrices having exactly 2 units in every row and every column is described in the paper. After analysing the work of the algorithm a formula for calculating the number of these matrices has been obtained. This formula is known and has been obtained using other methods, which by their nature are purely analytical and not constructive. Thus a new, constructive proof of this known formula has been obtained.
Cosmological implications of Born-Infeld-$f(R)$ gravity
Creators: name: Kibaroğlu, Salih
name: Elizalde, Emilio
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A modified Born-Infeld gravitation theory with a $f\left(R\right)$ function being added to the determinant action is analyzed from a cosmological viewpoint. The corresponding accelerating dynamics are studied in a simplified conformal approach without matter. Three different structures for the auxiliary metric function are analyzed, with the aim to establish a deeper understanding of the role of this function in cosmology. After performing the analysis, it is seen that, by modifying the auxiliary metric function, a Big Rip singularity or either a Little Rip dark energy model may arise.
description: 7 pages, 3 figures. This version was accepted in IJMPD
Starburst-AGN mixing: I. NGC 7130
Creators: name: Davies, Rebecca L.
name: Rich, Jeffrey A.
name: Kewley, Lisa J.
name: Dopita, Michael A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present an integral field spectroscopic study of the Luminous Infrared Galaxy (LIRG) NGC 7130, a known starburst-AGN composite galaxy. We employ standard emission line ratio diagnostics and maps of velocity dispersion and velocity field to investigate how the dominant ionising sources change as a function of radius. From the signatures of both star formation and AGN activity we show that NGC 7130 is a remarkably clean case of starburst-AGN mixing. We find a smooth transition from AGN dominated emission in the centre to pure star forming activity further out, from which we can estimate the radius of the extended narrow line region to be 1.8 +/- 0.8 kpc. We calculate that the fraction of [OIII] luminosity due to star formation and AGN activity is 30 +/- 2% and 70 +/- 3% respectively, and that the fraction of H-alpha luminosity due to star formation and AGN activity is 65 +/- 3% and 35 +/- 2% respectively. We conclude with a discussion of the importance and potential of starburst-AGN mixing for future studies of the starburst-AGN connection.
description: 12 pages, 10 figures, accepted for publication in MNRAS
Highly efficient generation of single-mode photon pairs using a crystalline whispering gallery mode resonator
Creators: name: Förtsch, Michael
name: Schunk, Gerhard
name: Fürst, Josef U.
name: Strekalov, Dmitry
name: Gerrits, Thomas
name: Stevens, Martin J.
name: Sedlmeir, Florian
name: Schwefel, Harald G. L.
name: Nam, Sae Woo
name: Leuchs, Gerd
name: Marquardt, Christoph
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We report a highly efficient source of narrow-band photon pairs based on parametric down-conversion in a crystalline whispering gallery mode resonator. Remarkably, each photon of a pair is strictly emitted into a single spatial and temporal mode, as witnessed by Glaubers autocorrelation function. We explore the phase-matching conditions in spherical geometries, and determine the requirements of the single-mode operation. Understanding these conditions has allowed us to experimentally demonstrate a single-mode pair-detection rate of $0.97 \cdot 10^6$ pairs/s per mW pump power per 20 MHz bandwidth without the need of additional filter cavities.
description: 7 pages, 6 figures
Reproducibility package for "Reproducible Research and GIScience: an evaluation using GIScience conference papers"
Creators: name: Nüst, Daniel
name: Ostermann, Frank
name: Granell, Carlos
name: Hofer, Barbara
name: Konkol, Markus
Publisher: name: Zenodo
Year: 2020
Subjects: reproducible research
GIScience
open science

description: Data and code for research article Reproducible Research and GIScience: an evaluation using GIScience conference papers. This record is a preservation of the collaborative project at https://github.com/nuest/reproducible-research-at-giscience/. A preprint is publised on EarthArXiv at https://doi.org/10.31223/X5ZK5V.
description: The documents in this repository are licensed under a Creative Commons Attribution 4.0 International License. All contained code is licensed under the Apache License 2.0. The data used is licensed under a Open Data Commons Attribution License.
Application of Machine Learning in Seismic Fragility Assessment of Bridges with SMA-Restrained Rocking Columns
Creators: name: Akbarnezhad, Miles
name: Salehi, Mohammad
name: DesRoches, Reginald
Publisher: name: arXiv
Year: 2022
Subjects: subject: Geophysics (physics.geo-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: This paper evaluates the seismic fragility of a two-span reinforced concrete (RC) bridge with shape memory alloy (SMA)-restrained rocking (SRR) columns through machine learning (ML) techniques. SRR columns incorporate a combination of replaceable superelastic NiTi (SMA) links and mild steel energy-dissipating links to achieve self-centering and energy dissipation, respectively, while their rocking joints are protected against compressive concrete damage through steel jacketing. To produce seismic fragility functions, initially, multi-parameter probabilistic seismic demand models (PSDMs) are generated for various engineering demand parameters through five different ML techniques (including neural network) and considering various sources of uncertainty, and the most accurate PSDMs are selected. The selected PSDMs are then interpreted using four different methods to investigate the effects of two key SRR column design parameters (self-centering coefficient and SMA link initial strain) and ambient temperature on the seismic performance of SRR columns. Subsequently, using neural networks, the PSDMs developed earlier, and appropriate capacity models, multi-parameter fragility functions are developed for various bridge damage states. After examining the effects of the two SRR column design parameters on the seismic fragility of the bridge, its seismic fragility is compared with those of the same bridge with monolithic RC and posttensioned (PT) rocking columns. It is shown that, in general, increasing the initial strain of the SMA links and decreasing the self-centering coefficient as possible (i.e., without compromising the self-centering) reduce the overall bridge damage. In addition, even considering the ambient temperature's uncertainty, SRR columns are proven, at least, as effective as PT columns in mitigating the seismic damage of the bridges of monolithic RC columns.
A unified description of solvent effects in the helix-coil transition
Creators: name: Badasyan, Artem
name: Tonoyan, Shushanik A.
name: Giacometti, Achille
name: Podgornik, Rudolf
name: Parsegian, V. Adrian
name: Mamasakhlisov, Yevgeni Sh.
name: Morozov, Vladimir F.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Biomolecules (q-bio.BM)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: We analyze the problem of the helix-coil transition in explicit solvents analytically by using spin-based models incorporating two different mechanisms of solvent action: explicit solvent action through the formation of solvent-polymer hydrogen bonds that can compete with the intrinsic intra-polymer hydrogen bonded configurations (competing interactions) and implicit solvent action, where the solvent-polymer interactions tune biopolymer configurations by changing the activity of the solvent (non-competing interactions). The overall spin Hamiltonian is comprised of three terms: the background \emph{in vacuo} Hamiltonian of the "Generalized Model of Polypeptide Chain" type and two additive terms that account for the two above mechanisms of solvent action. We show that on this level the solvent degrees of freedom can be {\sl explicitly} and {\sl exactly} traced over, the ensuing effective partition function combining all the solvent effects in a unified framework. In this way we are able to address helix-coil transitions for polypeptides, proteins, and DNA, with different buffers and different external constraints. Our spin-based effective Hamiltonian is applicable for treatment of such diverse phenomena as cold denaturation, effects of osmotic pressure on the cold and warm denaturation, complicated temperature dependence of the hydrophobic effect as well as providing a conceptual base for understanding the behavior of Intrinsically Disordered Proteins and their analogues.
description: 12 pages, 12 figures, to be submitted to PRE
The ESO-VLT MIKiS survey reloaded: exploring the internal kinematics of NGC 6440
Creators: name: Leanza, Silvia
name: Pallanca, Cristina
name: Ferraro, Francesco R.
name: Lanzoni, Barbara
name: Dalessandro, Emanuele
name: Cadelano, Mario
name: Vesperini, Enrico
name: Origlia, Livia
name: Mucciarelli, Alessio
name: Valenti, Elena
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In the context of the ESO-VLT Multi-Instrument Kinematic Survey (MIKiS) of Galactic globular clusters, here we present the line-of-sight velocity dispersion profile of NGC 6440, a massive globular cluster located in the Galactic bulge. By combining the data acquired with four different spectrographs, we obtained the radial velocity of a sample of $\sim 1800$ individual stars distributed over the entire cluster extension, from $\sim$0.1$"$ to 778$"$ from the center. Using a properly selected sample of member stars with the most reliable radial velocity measures, we derived the velocity dispersion profile up to 250$"$ from the center. The profile is well described by the same King model that best fits the projected star density distribution, with a constant inner plateau (at $σ_0 \sim $ 12 km s$^{-1}$) and no evidence of a central cusp or other significant deviations. Our data allowed to study the presence of rotation only in the innermost regions of the cluster (r < 5$"$), revealing a well-defined pattern of ordered rotation with a position angle of the rotation axis of $\sim$132 $\pm$ 2° and an amplitude of $\sim$3 km s$^{-1}$ (corresponding to Vrot/$σ_0 \sim$ 0.3). Also, a flattening of the system qualitatively consistent with the rotation signal has been detected in the central region.
description: 20 pages, 11 figures, 4 tables, accepted for publication in ApJ
Clinical psychologists’ experiences of negotiating dual identities as mental health service users and service providers
Creators: name: Rhinehart, Molly
Publisher: name: Lancaster University
Year: 2023

description: This thesis consists of three papers: a literature review, research paper, and a critical appraisal. The systematic literature review explores how key individuals in a young person’s life respond to the young person’s self-harm. A thematic synthesis was undertaken on 12 papers. Five themes were identified: 1) initial responses fuelled by emotions, 2) the importance of a calm façade, 3) modifying my approach and our relationship, 4) offering support, and 5) we need more help! Recommendations highlight the importance of training for education and healthcare staff. The findings also illustrate the need for a greater focus on the experiences of peers caring for their friend who is self-harming, and the need for support programmes for parents of young people who self-harm. The research paper explores the experiences of clinical psychologists in negotiating dual identities as both mental health service user and service provider. Narrative analysis was utilised to explore the experiences of 12 participants. The analysis resulted in the development of five chapters: Prologue: Developing Dual Identities, Chapter One: Separation of Identities, Chapter Two: Negotiation of Identities, Chapter Three: Co-Existence of Identities, and an Epilogue: Looking Forward. The findings discuss the initial separation of service user and service provider identities, often due to stigma, and community expectations placed on the service provider role. Participants negotiated their identities often by prioritising one identity and reframing their service user identity as part of their ‘humanness’. Participants settled at different points of their negotiation, ranging from separate but alongside each other, to fully integrated identities. The critical appraisal provides a personal exploration of multiple identities during clinical training and writing the two papers. The appraisal also considers how the two papers are connected to provide two perspectives on stigmatised experiences, and the commonality between the clinical implications for both papers.
Photoassociation of ultracold molecules near a Feshbach resonance as a probe of the electron-proton mass ratio variation
Creators: name: Gacesa, Marko
name: Côté, Robin
Publisher: name: arXiv
Year: 2014
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We show that the photoassociation (PA) rate of ultracold diatomic molecules in the vicinity of a Feshbach resonance could be used to probe variations of the electron-to-proton mass ratio $β= m_e/m_p$, a quantity related to other fundamental constants via the $Λ_{\mathrm{QCD}}$ scale. The PA rate exhibits two features near a Feshbach resonance, a minimum and a maximum, which are very sensitive to the details of the interactions and the exact mass of the system. The effect and detection threshold are illustrated in the formation rates of ultracold Li$_2$ and LiNa molecules by performing coupled-channel calculations in an external magnetic field. We find that the PA rate is particularly sensitive near narrow Feshbach resonances in heavy molecules, where it might be possible to detect relative variability of $β$ on the order of $10^{-15}-10^{-16}$. We also use a two-channel model to derive a proportionality relation between the variation of the PA rate and $β$ applicable to diatomic molecules.
description: 9 pages, 6 figures; submitted to the Journal of Molecular Spectroscopy
title: Llama
title: Towards Low Latency Live Adaptive Streaming
titleType: Subtitle
Creators: name: Lyko, Tomasz
Publisher: name: Lancaster University
Year: 2023

description: Multimedia streaming, including on-demand and live delivery of content, has become the largest service, in terms of traffic volume, delivered over the Internet. The ever-increasing demand has led to remarkable advancements in multimedia delivery technology over the past three decades, facilitated by the concurrent pursuit of efficient and quality encoding of digital media. Today, the most prominent technology for online multimedia delivery is HTTP Adaptive Streaming (HAS), which utilises the stateless HTTP architecture - allowing for scalable streaming sessions that can be delivered to millions of viewers around the world using Content Delivery Networks. In HAS, the content is encoded at multiple encoding bitrates, and fragmented into segments of equal duration. The client simply fetches the consecutive segments from the server, at the desired encoding bitrate determined by an ABR algorithm which measures the network conditions and adjusts the bitrate accordingly. This method introduces new challenges to live streaming, where the content is generated in real-time, as it suffers from high end-to-end latency when compared to traditional broadcast methods due to the required buffering at client. This thesis aims to investigate low latency live adaptive streaming, focusing on the reduction of the end-to-end latency. We investigate the impact of latency on the performance of ABR algorithms in low latency scenarios by developing a simulation model and testing prominent on-demand adaptation solutions. Additionally, we conduct extensive subjective testing to further investigate the impact of bitrate changes on the perceived Quality of Experience (QoE) by users. Based on these investigations, we design an ABR algorithm suitable for low latency scenarios which can operate with a small client buffer. We evaluate the proposed low latency adaption solution against on-demand ABR algorithms and the state-of-the-art low latency ABR algorithms, under realistic network conditions using a variety of client and latency settings.
The Peculiar Radio-Loud Narrow Line Seyfert 1 Galaxy 1H 0323+342
Creators: name: Paliya, Vaidehi S.
name: Sahayanathan, S.
name: Parker, M. L.
name: Fabian, A. C.
name: Stalin, C. S.
name: Anjum, Ayesha
name: Pandey, S. B.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present a multi-wavelength study of the radio-loud narrow line Seyfert 1 galaxy (NLSy1), 1H 0323+342, detected by Fermi Gamma Ray Space Telescope. Multi-band light curves show many orphan X-ray and optical flares having no corresponding γ-ray counterparts. Such anomalous variability behavior can be due to different locations of the emission region from the central source. During a large flare, γ-ray flux doubling time scale as small as $\sim$ 3 hours is noticed. We built spectral energy distribution (SED) during different activity states and modeled them using an one-zone leptonic model. The shape of the optical/UV component of the SEDs is dominated by accretion disk emission in all the activity states. In the X-ray band, significant thermal emission from the hot corona is inferred during quiescent and first flaring states, however, during subsequent flares, non-thermal jet component dominates. The γ-ray emission in all the states can be well explained by inverse-Compton scattering of accretion disk photons reprocessed by the broad line region. The source showed violent intra-night optical variability, coinciding with one of the high γ-ray activity states. An analysis of the overall X-ray spectrum fitted with an absorbed power-law plus relativistic reflection component hints for the presence of Fe K-α line and returns a high black hole spin value of a=0.96 $\pm$ 0.14. We argue that 1H 0323+342 possesses dual characteristics, akin to flat spectrum radio quasars (FSRQs) as well as radio-quiet NLSy1s, though at a low jet power regime compared to powerful FSRQs.
description: 49 pages, 12 figures, 7 tables, to appear in The Astrophysical Journal
title: The need for funding in Biofilm Standardisation
Creators: name: National Biofilms Innovation Centre,
Publisher: name: University of Southampton
Year: 2023

description: Funding for biofilm standardisation projects is critical for addressing current global challenges and advancing research and technology developments. By promoting consistency and standardisation, these efforts can have a significant impact on improving public health and the environment and on supporting multiple economic sectors.
NBIC recommends that funders, standardisation organisations and regulators should take the following actions:
-Support the creation of a catalogue of standardised methodologies, validated and recommended by experts, which could be build e.g., under the umbrella of the British Standards Institute (BSI) and British Standards Online (BSOL).
-Put a strategy in place for the development of guidelines, validated procedures and standardised methods that account for the inherent complexity and variability of biofilms to support reliable and reproducible research and products across sectors.
-Recognise the importance of metrology and validation research, such as round-robin studies, and provide the necessary support and resources to conduct them successfully.
-UK Research Councils, especially Innovate UK, to provide a platform for industry and researchers to work together to support voluntary standardisation as an industry driven activity.
-Establish a funding programme, readily accessible to both academic researchers and industry to encourage and enable collaborative, interdisciplinary research and metrology, and support standardisation (prenormative and normative) activities.
-Encourage contributions from wider academic expertise, industry researchers and end-users to accelerate the development of standardised methodologies, especially in the areas such as biofilm affected industries, where the need is strong, yet progress is very slow
Dissipative creation of three-dimensional entangled state in optical cavity via spontaneous emission
Creators: name: Shao, Xiao-Qiang
name: Zheng, Tai-Yu
name: Oh, C. H.
name: Zhang, Shou
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a dissipative protocol to engineer two $^{87}Rb$ atoms into a form of three-dimensional entangled state via spontaneous emission. The combination of coupling between ground states via microwave fields and dissipation induced by spontaneous emission make the current scheme deterministic and a stationary entangled state can always be achieved without state initialization. Moreover, this scheme can be straightforwardly generalized to preparation of an $N$-dimensional entangled state in principle.
description: 5 pages, 5 figures
Quantum Tunneling of Ultralight Dark Matter Out of Satellite Galaxies
Creators: name: Hertzberg, Mark P.
name: Loeb, Abraham
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The idea of ultralight scalar (axion) dark matter is theoretically appealing and may resolve some small-scale problems of cold dark matter; so it deserves careful attention. In this work we carefully analyze tunneling of the scalar field in dwarf satellites due to the tidal gravitational force from the host halo. The tidal force is far from spherically symmetric; causing tunneling along the axis from the halo center to the dwarf, while confining in the orthogonal plane. We decompose the wave function into a spherical term plus higher harmonics, integrate out angles, and then numerically solve a residual radial Schrödinger-Poisson system. By demanding that the core of the Fornax dwarf halo can survive for at least the age of the universe places a bound on the dark matter particle mass $2\times 10^{-22}\,\mbox{eV}\lesssim m\lesssim 6\times 10^{-22}\,$eV. Interestingly, we show that if another very low density halo is seen, then it rules out the ultralight scalar as core proposal completely. Furthermore, the non-condensed particles likely impose an even sharper lower bound. We also determine how the residual satellites could be distributed as a function of radius.
description: 7 pages, 2 figures, in double column format. V2: Updated towards version published in JCAP
Shaping of AGB outflows by wind-companion interactions in binary and hierarchical triple systems
Creators: name: Jolien, Malfait
Publisher: name: Zenodo
Year: 2022

description: At the end of their lives, low and intermediate mass stars scatter their envelope throughout the interstellar medium via a dust-driven stellar wind. For decades, modelling endeavours of these outflows have assumed that these winds are spherically symmetric. However, recent high-spatial resolution observations reveal that the winds of these Asymptotic Giant Branch (AGB) stars typically possess a high degree of complexity, including spirals, disks, clumps, bipolar outflows, etc., and showing strong resemblance with the intricate morphologies of their successors being Post-AGB stars and planetary nebulae. Many of these observed wind structures are believed to be formed primarily by the impact of one or more companion stars or planets. If neglecting the 3D structures and the impact of these companions, systematic errors may occur in the estimate of critical stellar evolution parameters such as the mass-loss rate.
 With sophisticated 3D hydro-dynamical modelling tools, constructed with the SPH solver PHANTOM, we confirm that the observed wind structures can be formed by the gravitational interaction of one or multiple companions with the AGB outflow, and the induced orbital motion of all components. Nevertheless, a number of observed targets posses complex-structured nebulae of which the morphological shape can still not be understood on the basis of the current set of theoretical models for such systems. To advance our insights on the origins of these complex nebulae, I present a comprehensive set of high-resolution models of a stellar wind perturbed by (i) a close, solar-mass companion in orbits of varying eccentricity, and by (ii) two companion stars in various hierarchical triple configurations.
 By analysing the structure formation in these simulations, we unravel how and by which binary/triple configurations the observed AGB wind structures can be created.
Patchy Forsterite Clouds in the Atmospheres of Two Highly Variable Exoplanet Analogs
Creators: name: Vos, Johanna M.
name: Burningham, Ben
name: Faherty, Jacqueline K.
name: Alejandro, Sherelyn
name: Gonzales, Eileen
name: Calamari, Emily
name: Gagliuffi, Daniella Bardalez
name: Visscher, Channon
name: Tan, Xianyu
name: Morley, Caroline V.
name: Marley, Mark
name: Gemma, Marina E.
name: Whiteford, Niall
name: Gaarn, Josefine
name: Park, Grace
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present an atmospheric retrieval analysis of a pair of highly variable, $\sim200~$Myr old, early-T type planetary-mass exoplanet analogs SIMP J01365662+0933473 and 2MASS J21392676+0220226 using the Brewster retrieval framework. Our analysis, which makes use of archival $1-15~μ$m spectra, finds almost identical atmospheres for both objects. For both targets, we find that the data is best described by a patchy, high-altitude forsterite (Mg$_2$SiO$_4$) cloud above a deeper, optically thick iron (Fe) cloud. Our model constrains the cloud properties well, including the cloud locations and cloud particle sizes. We find that the patchy forsterite slab cloud inferred from our retrieval may be responsible for the spectral behavior of the observed variability. Our retrieved cloud structure is consistent with the atmospheric structure previously inferred from spectroscopic variability measurements, but clarifies this picture significantly. We find consistent C/O ratios for both objects which supports their formation within the same molecular cloud in the Carina-Near Moving Group. Finally, we note some differences in the constrained abundances of H$_2$O and CO which may be caused by data quality and/or astrophysical processes such as auroral activity and their differing rotation rates. The results presented in this work provide a promising preview of the detail with which we will characterize extrasolar atmospheres with JWST, which will yield higher quality spectra across a wider wavelength range.
description: Accepted for publication in ApJ
Wind braking of magnetars: to understand magnetar's multiwave radiation properties
Creators: name: Tong, H.
name: Xu, R. X.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Magnetars are proposed to be peculiar neutron stars powered by their super strong magnetic field. Observationally, anomalous X-ray pulsars and soft gamma-ray repeaters are believed to be magnetar candidates. While more and more multiwave observations of magnetars are available, unfortunately, we see accumulating failed predictions of the traditional magnetar model. These challenges urge rethinking of magnetar. Wind braking of magnetars is one of the alternative modelings. The release of magnetic energy may generate a particle outflow (i.e., particle wind), that results in both an anomalous X-ray luminosity and significantly high spindown rate. In this wind braking scenario, only strong multipole field is necessary for a magnetar (a strong dipole field is no longer needed). Wind braking of magnetars may help us to understand their multiwave radiation properties, including (1) Non-detection of magnetars in Fermi-LAT observations, (2) The timing behaviors of low magnetic field magnetars, (3) The nature of anti-glitches, (4) The criterion for magnetar's radio emission, etc. In the wind braking model of magentars, timing events of magnetars should always be accompanied by radiative events. It is worth noting that the wind engine should be the central point in the research since other efforts with any reasonable energy mechanism may also reproduce the results.
description: 6 pages, 1 figure, submitted to conference proceeding of SMFNS2013 (Strong electromagnetic field and neutron stars 2013)
Groebner basis methods for stationary solutions of a low-dimensional model for a shear flow
Creators: name: Pausch, Marina
name: Grossmann, Florian
name: Eckhardt, Bruno
name: Romanovski, Valery G.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We use Groebner basis methods to extract all stationary solutions for the 9-mode shear flow model that is described in Moehlis et al, New J. Phys. 6, 54 (2004). Using rational approximations to irrational wave numbers and algebraic manipulation techniques we reduce the problem of determining all stationary states to finding roots of a polynomial of order 30. The coefficients differ by 30 powers of 10 so that algorithms for extended precision are needed to extract the roots reliably. We find that there are eight stationary solutions consisting of two distinct states that each appear in four symmetry-related phases. We discuss extensions of these results for other flows.
Separated spin-up and spin-down quantum hydrodynamics of degenerated electrons: spin-electron acoustic wave appearance
Creators: name: Andreev, Pavel A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum hydrodynamic (QHD) model of charged spin-1/2 particles contains physical quantities defined for all particles of a species including particles with spin-up and with spin-down. Different population of states with different spin direction is included in the spin density (magnetization). In this paper we derive a QHD model, which separately describes spin-up electrons and spin-down electrons. Hence we consider electrons with different projection of spin on the preferable direction as two different species of particles. We show that numbers of particles with different spin direction do not conserve. Hence the continuity equations contain sources of particles. These sources are caused by the interactions of spins with magnetic field. Terms of similar nature arise in the Euler equation. We have that z-projection of the spin density is no longer an independent variable. It is proportional to difference between concentrations of electrons with spin-up and electrons with spin-down. In terms of new model we consider propagation of waves in magnetized plasmas of degenerate electrons and motionless ions. We show that new form of QHD equations gives all solutions obtained from traditional form of QHD equations with no distinguish of spin-up and spin-down states. But it also reveals a sound-like solution we call the spin-electron acoustic wave. Coincidence of most solutions is expected since we started derivation with the same basic equation.
description: 8 pages
Curvature-driven instabilities in thin active shells.
Creators: name: Giudici, Andrea
name: Biggins, John S
Publisher: name: Apollo - University of Cambridge Repository
Year: 2022
Subjects: Curvature
Instability
Geometry
Morphing
Shells

description: Spontaneous material shape changes, such as swelling, growth or thermal expansion, can be used to trigger dramatic elastic instabilities in thin shells. These instabilities originate in geometric incompatibility between the preferred extrinsic and intrinsic curvature of the shell, which may be modified by active deformations through the thickness and in plane, respectively. Here, we solve the simplest possible model of such instabilities, which assumes the shells are shallow, thin enough to bend but not stretch, and subject to homogeneous preferred curvatures. We consider separately the cases of zero, positive and negative Gauss curvature. We identify two types of supercritical symmetry-breaking instability, in which the shell's principal curvature spontaneously breaks discrete up/down symmetry and continuous planar isotropy. These are then augmented by inversion instabilities, in which the shell jumps subcritically between up/down broken symmetry states and rotation instabilities, in which the curvatures rotate by 90° between states of broken isotropy without release of energy. Each instability has a thickness-independent threshold value for the preferred extrinsic curvature proportional to the square root of Gauss curvature. Finally, we show that the threshold for the isotropy-breaking instability is the same for deep spherical caps, in good agreement with recently published data.
Timelike Compton scattering in ultraperipheral $pPb$ collisions
Creators: name: Xie, Ya-Ping
name: Goncalves, V. P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The study of exclusive processes in photon - induced interactions allow us to probe the generalized parton distributions (GPDs), which provide information about the 3 dimensional description of the quark and gluon content of hadrons. In this paper we investigate the timelike Compton scattering (TCS) in ultraperipheral $pPb$ collisions at the LHC. Such process is characterized by the exclusive dilepton production through the subprocess $γp \rightarrow γ^*p \rightarrow l^+ l^- p$, with the real photon in the initial state being emitted by the nucleus. Assuming a given model for the GPDs, the TCS differential cross section is estimated as well the contribution associated to the interference between the TCS and Bethe - Heitler (BH) amplitudes. Predictions for the TCS, BH and interference contributions are presented considering the kinematical range covered by the LHC detectors.
Inclusion of regular and linear languages in group languages
Creators: name: Yordzhev, Krasimir
Publisher: name: arXiv
Year: 2013
Subjects: subject: Formal Languages and Automata Theory (cs.FL)
subject: FOS: Computer and information sciences
subject: 68Q45, 68Q70

description: Let $Σ= X\cup X^{-1} = \{ x_1 ,x_2 ,..., x_m ,x_1^{-1} ,x_2^{-1} ,..., x_m^{-1} \}$ and let $G$ be a group with set of generators $Σ$. Let $\mathfrak{L} (G) =\left\{ \left. ω\in Σ^* \; \right\vert \;ω\equiv e \; (\textrm{mod} \; G) \right\} \subseteq Σ^*$ be the group language representing $G$, where $Σ^*$ is a free monoid over $Σ$ and $e$ is the identity in $G$. The problem of determining whether a context-free language is subset of a group language is discussed. Polynomial algorithms are presented for testing whether a regular language, or a linear language is included in a group language. A few finite sets are built, such that each of them is included in the group language $\mathfrak{L} (G)$ if and only if the respective context-free language is included in $\mathfrak{L} (G)$.
description: 14 pages
Multidimensional spectroscopy with entangled light; loop vs ladder delay scanning protocols
Creators: name: Dorfman, Konstantin E.
name: Mukamel, Shaul
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Chemical Physics (physics.chem-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Multidimensional optical signals are commonly recorded by varying the delays between time ordered pulses. These control the evolution of the density matrix and are described by ladder diagrams. We propose a new non-time-ordered protocol based on following the time evolution of the wavefunction and described by loop diagrams. The time variables in this protocol allow to observe different types of resonances and reveal information about intraband dephasing not readily available by time ordered techniques. The time variables involved in this protocol become coupled when using entangled light, which provides high selectivity and background free measurement of the various resonances. Entangled light can resolve certain states even when strong background due to fast dephasing suppresses the resonant features when probed by classical light.
Critical spin-flip scattering at the helimagnetic transition of MnSi
Creators: name: Kindervater, J.
name: Häußler, W.
name: Janoschek, M.
name: Pfleiderer, C.
name: Böni, P.
name: Garst, M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report spherical neutron polarimetry (SNP) and discuss the spin-flip scattering cross sections as well as the chiral fraction $η$ close to the helimagnetic transition in MnSi. For our study, we have developed a miniaturised SNP device that allows fast data collection when used in small angle scattering geometry with an area detector. Critical spin-flip scattering is found to be governed by chiral paramagnons that soften on a sphere in momentum space. Carefully accounting for the incoherent spin-flip background, we find that the resulting chiral fraction $η$ decreases gradually above the helimagnetic transition reflecting a strongly renormalised chiral correlation length with a temperature dependence in excellent quantitative agreement with the Brazovskii theory for a fluctuation-induced first order transition.
description: 5 pages, 3 figures
Random Permutations, Random Sudoku Matrices and Randomized Algorithms
Creators: name: Yordzhev, Krasimir
Publisher: name: arXiv
Year: 2013
Subjects: subject: Combinatorics (math.CO)
subject: Data Structures and Algorithms (cs.DS)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 05B20, 65C05, 68W40

description: Some randomized algorithms, used to obtain a random $n^2 \times n^2$ Sudoku matrix, where $n$ is a natural number, is reviewed in this study. Below is described the set $Π_n$ of all $(2n) \times n$ matrices, consisting of elements of the set $\mathbb{Z}_n =\{ 1,2,\ldots ,n\}$, such that every row is a permutation. It is proved that such matrices would be particularly useful in developing efficient algorithms in generating Sudoku matrices. An algorithm to obtain random $Π_n$ matrices is presented in this paper. The algorithms are evaluated according to two criteria - probability evaluation, and time evaluation. This type of criteria is interesting from both theoretical and practical point of view because they are particularly useful in the analysis of computer programs.