cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Exploring the Vacuum Geometry of N=1 Gauge Theories
Creators: name: Gray, James
name: He, Yang-Hui
name: Jejjala, Vishnu
name: Nelson, Brent D.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Algebraic Geometry (math.AG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Using techniques of algorithmic algebraic geometry, we present a new and efficient method for explicitly computing the vacuum space of N=1 gauge theories. We emphasize the importance of finding special geometric properties of these spaces in connecting phenomenology to guiding principles descending from high-energy physics. We exemplify the method by addressing various subsectors of the MSSM. In particular the geometry of the vacuum space of electroweak theory is described in detail, with and without right-handed neutrinos. We discuss the impact of our method on the search for evidence of underlying physics at a higher energy. Finally we describe how our results can be used to rule out certain top-down constructions of electroweak physics.
description: 35 pages, 2 figures, LaTeX
Theory of Quantum Transport in Nano and Molecular Scale Systems
Creators: name: Alwhaibi, Noorah
Publisher: name: Lancaster University
Year: 2021
Subjects: Transport
Electronic
nanoelectronics
conductance

description: This thesis investigates the fundamental aspects of the molecular-scale junctions and their electrical properties. Experimental and theoretical studies assessed the importance of finding ways to get consistent and reproducible improvements in electronics devices fabrications techniques. In this context, I will start this thesis by introducing a general discussion about using the density functional theory (DFT), and Green's function to study transport calculations at a molecular scale. Then, I will present the theoretical and experimental benzo-(bis)imiadzol molecular studies in chapter 4. This study focusses on changes in the conductance as a consequence of chemical stimuli. I will demonstrate that benzo-bis(imidazole) conductance switching upon protonation depends on the lateral functional groups. The protonated H-substituted molecule shows a higher conductance than the neutral one (Gpro>Gneu), while the opposite (Gneu>Gpro) is observed for a molecule functionalized by amino-phenyl groups. Based on theoretical calculations, I conclude that these opposite behaviours depend on the electronic coupling between molecules and electrodes. Furthermore, quantum interference properties have recently attracted excessive interest in electron transport studies at the single-molecule scale. Within this framework, myself and collaborators have aimed to improve the efficiency of pi-stacked molecules in controlling quantum interference by carefully designing them. Chapter 5 introduces a novel strategy for designing folded carbazoles with low conductance in different structures. This strategy highlights the presence or absence of destructive quantum interference in different configurations. This project is part of a collaborations with the experimental group at the University of Madrid, which is ongoing at present.
Digital Divides and Online Media
Creators: name: Ruohonen, Jukka
name: Tuikka, Anne-Marie
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Digital divide has been a common concern during the past two or three decades; traditionally, it refers to a gap between developed and developing countries in the adoption and use of digital technologies. Given the importance of the topic, digital divide has been also extensively studied, although, hitherto, there is no previous research that would have linked the concept to online media. Given this gap in the literature, this paper evaluates the "maturity" of online media in 134 countries between 2007 and 2016. Maturity is defined according to the levels of national online media consumption, diversity of political perspectives presented in national online media, and consensus in reporting major political events in national online media. These aspects are explained by considering explanatory factors related to economy, infrastructure, politics, and administration. According to the empirical results based on a dynamic panel data methodology, all aspects except administration are also associated with the maturity of national online media.
description: Proceedings of the 5th International Conference on E-Society, E-Education and E-Technology (ICSET 2021), Taipei (online), ACM, pp. 157-163
Blocked regular fractional factorial designs with minimum aberration
Creators: name: Xu, Hongquan
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62K15 (Primary) 62K05 (Secondary)

description: This paper considers the construction of minimum aberration (MA) blocked factorial designs. Based on coding theory, the concept of minimum moment aberration due to Xu [Statist. Sinica 13 (2003) 691--708] for unblocked designs is extended to blocked designs. The coding theory approach studies designs in a row-wise fashion and therefore links blocked designs with nonregular and supersaturated designs. A lower bound on blocked wordlength pattern is established. It is shown that a blocked design has MA if it originates from an unblocked MA design and achieves the lower bound. It is also shown that a regular design can be partitioned into maximal blocks if and only if it contains a row without zeros. Sufficient conditions are given for constructing MA blocked designs from unblocked MA designs. The theory is then applied to construct MA blocked designs for all 32 runs, 64 runs up to 32 factors, and all 81 runs with respect to four combined wordlength patterns.
description: Published at http://dx.doi.org/10.1214/009053606000000777 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Adult sensory capacities as a function of birth risk factors
Creators: name: Harland, Renata E.
Publisher: name: University of British Columbia
Year: 2009

description: This study examined the relationship between the events surrounding one's birth and subsequent sensory capacity in adulthood. Data was extracted from the Human Neuropsychology and Perception Laboratory Data Bank at the University of British Columbia to determine whether mild birth risk factors have an impact on adult sensory capacities. The final sample consisted of 716 female and 529 male participants (mean age = 19.9) for whom both an indication of birth stress and at least one measure of sensory capacity were available. The extent of birth stress was determined by having subjects complete a questionnaire examining the incidence of nine birth risk factors during their birth: a) long labour b) breech birth c) breathing difficulty d) instrument delivery e) Caesarian delivery f) multiple birth g) premature birth h) low birth weight and i) high risk birth order. Seven sensory capacities were also tested using standard laboratory techniques; these included visual acuity, macular suppression, stereopsis, colour discrimination, pure tone hearing, speech recognition and sound localization. Significant associations between mild birth stressors and reduced adult capacity were found. Of the birth stressors examined, long labour was found to affect the sensory systems the most, possibly because other birth stressors such as hypoxia and forceps delivery often coincide with prolonged labours. Vision was found to be more vulnerable to birth stress effects than was audition, which may be due to the fact that the visual system matures more slowly than does the auditory system. These results suggest that it may be useful to include sensory factors in the pattern of deficits usually called the Alinormal Syndrome.
Two-jet inclusive cross sections in heavy-ion collisions in the perturbative QCD
Creators: name: Braun, M. A.
name: Kolevatov, R. S.
name: Vlahovic, B.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the framework of perturbative QCD, double inclusive cross sections for high $p_t$ parton production in nucleus-nucleus collisions are computed with multiple rescattering taken into account. The induced long-range correlations between numbers of jets at forward and backward rapidities are found to reach $10÷20$% for light nuclei at $\sqrt{s}=200$ GeV/c and to be suppressed for heavy nuclei and LHC energies.
description: 17 pages, 6 figures. V2: Major revisions
Automatically Detecting Cyberbullying Comments on Online Game Forums
Creators: name: Vo, Hanh Hong-Phuc
name: Tran, Hieu Trung
name: Luu, Son T.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Online game forums are popular to most of game players. They use it to communicate and discuss the strategy of the game, or even to make friends. However, game forums also contain abusive and harassment speech, disturbing and threatening players. Therefore, it is necessary to automatically detect and remove cyberbullying comments to keep the game forum clean and friendly. We use the Cyberbullying dataset collected from World of Warcraft (WoW) and League of Legends (LoL) forums and train classification models to automatically detect whether a comment of a player is abusive or not. The result obtains 82.69% of macro F1-score for LoL forum and 83.86% of macro F1-score for WoW forum by the Toxic-BERT model on the Cyberbullying dataset.
description: Published in the 2021 RIVF International Conference on Computing and Communication Technologies (RIVF)
Design of an IF section for a Galactic Emission Mapping experiment
Creators: name: Bergano, Miguel
name: Cupido, Luis
name: Barbosa, Domingos
name: Fonseca, Rui
name: Santos, Dinis M.
name: Smoot, George
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: In the context of the Galactic Emission Mapping collaboration, a galactic survey at 5GHz is in preparation to properly characterize the galactic foreground to the Cosmic Microwave Background Radiation (CMBR). For the North sky survey, a new receiver is being developed. This 5GHz heterodyne polarimeter has a high gain IF (intermediate frequency) chain using the latest RF technology and microstrip design that we describe in the present article. Working at 600MHz central frequency, it consists of a pre-amplifier with an integral band-pass filter followed by an amplifier with digitally controlled gain and a frequency converter to zero-IF that feeds the ADC of a four channel digital correlator (outside the scope of the present article). This paper focuses the design options and constraints and presents the simulations and experimental results of a circuit prototype.
description: accepted for publication and presentation at Conftele 2007, an IT and IEEE sponsored Conference (www.it.pt/conftele2007)
Assessment of the Impact of Heart Failure on Household Economic Well-being: Background and Methods
Creators: name: Sivadasanpillai Harikrishnan
name: Panniyammakal Jeemon
name: Ganapathi, Sanjay
name: Reethu Salim
name: Bahl, Ajay
name: Katageri, Anand
name: Animesh Mishra
name: Anoop George Alex
name: Bhavesh Roy
name: Bishav Mohan
name: Hasit Joshi
name: Jabir Abdullakutty
name: Paul, Justin
name: Rai, Manish
name: Cholenahally Nanjappa Manjunath
name: Negi, Prakash C
name: Durgaprasad Rajasekhar
name: Rishi Sethi
name: Satyanarayan Routray
name: Radhakrishnan Shanmugasundaram
name: Sumanta Shekhar Padhi
name: Syam Sunder Reddy
Publisher: name: figshare
Year: 2021
Subjects: subject: 110201 Cardiology (incl. Cardiovascular Diseases)
subject: FOS: Clinical medicine

description: Background and rationale: Heart failure (HF), which is an emerging public health issue, adversely affects the strained health system in India. The potential adverse impact of HF on the economic well-being of affected individuals and their families is narrated in various anecdotal reports. Further, HF is known to push the affected individuals and their dependents into poverty. However, there is limited research quantifying how HF impacts the economic well-being of households from the low and middle-income countries. Methods: We describe the methods of a detailed economic impact assessment of HF at the household level in India. The economic impact study in HF is initiated across 20 centres in India. The selected centres represent different regions in India stratified based on the prevailing stage of epidemiological transition levels (ETLs). We will collect data from 1800 patients with acute decompensated HF and within 6-15 months of follow-up from the time of initial admission. The data that we intend to collect will consist of a) household healthcare expenditure including out-of-pocket expenditure, b) financing mechanisms used by households and (c) the impoverishing effects of health expenditures including distress financing and catastrophic health expenditure. Trained staff at each centre will collect relevant data by using a validated and structured interview schedule. The study will have 80% power, after accounting for five percent non-response rate, to test eight percent difference in primary outcome (proportion of families under distress financing) between different ETLs. Impact: The results from the study will help policy makers in understanding the micro-economic impact of HF in India and aid in allocation of appropriate resources for prevention and control of HF.
$N$-band Hopf insulator
Creators: name: Lapierre, Bastien
name: Neupert, Titus
name: Trifunovic, Luka
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the generalization of the three-dimensional two-band Hopf insulator to the case of many bands, where all the bands are separated from each other by band gaps. The obtained $\mathbb{Z}$ classification of such a $N$-band Hopf insulator is related to the quantized isotropic magnetoelectric coefficient of its bulk. The boundary of a $N$-band Hopf insulator can be fully gapped, and we find that there is no unique way of dividing a finite system into bulk and boundary. Despite this non-uniqueness, we find that the magnetoelectric coefficient of the bulk and the anomalous Hall conductivity of the boundary are quantized to the same integer value. We propose an experiment where the quantized boundary effect can be measured in a non-equilibrium state.
description: v2: 18 pages, 12 figures. Published version
Synergies and trade-offs between climate mitigation and poverty alleviation for East Africa’s dairy sector
Creators: name: Hawkins, James
Publisher: name: Lancaster University
Year: 2021
Subjects: dairy
greenhouse gases
climate change mitigation
sustainable development
land use change
food security
poverty alleviation
East Africa
NDCs

description: Throughout East Africa, cattle play important roles in livelihoods of the rural poor and in supporting urban food security. As a result of low productivity, the dairy sector emits as much as 20 times more greenhouse gas (GHG) emissions per unit product than high income countries, while also acting as a leading driver of emissions from land use change. Productivity improvements may contribute to domestic food security and poverty alleviation jointly with GHG reductions for national climate targets. Yet the multi-functional roles cattle play within livelihoods imply mitigation strategies must be designed with care. Using household survey data from Kenya and Tanzania and a system modelling framework, this thesis evaluates options to better align country dairy policy initiatives with GHG targets under nationally determined contributions (NDCs). The thesis includes an empirical chapter (3) informing of variability in GHG emissions and dairy production practices across Kenya and Tanzania to inform mitigation interventions. Two model chapters then assess respectively the potential of feeding efficiency gains (chapter 4) and genetic gains combined with improved feeding (chapter 5) to contribute to GHG reductions consistent with development targets envisaged by the ‘dairy roadmap’ (part of the 2016 ‘Livestock Master Plan’). Feeding efficiency gains alone have negligible potential to meet climate targets consistent with growth in milk production (chapter 3). Instead, realising milk production targets with absolute reductions in GHG emissions will depend on reaching ambitious breed adoption targets (chapter 4). Realising such targets could increase milk production to 70% and 100% of the national target with respectively 29.6 ± 13.4% (95% CI) and 13.8 ± 17.1% GHG reductions relative to the baseline. Cost-benefit accounting indicates improved breeds would have net positive welfare impacts, increasing income on average by 195 to 261 USD capita-1 year-1 for producers. Since genetic gains are a central feature of Tanzania’s dairy roadmap, the findings demonstrate the likely congruence between climate mitigation and national dairy development initiatives in East Africa, suggesting that improved breeds can deliver both climate and livelihood benefits within high agro-ecologic potential systems of East Africa.
The X-ray properties of the dwarf Magellanic-type galaxy NGC 55
Creators: name: Stobbart, A-M.
name: Roberts, T. P.
name: Warwick, R. S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present an analysis of the X-ray properties of the Magellanic-type galaxy NGC 55 based on two contiguous XMM-Newton observations. We detect a total of 137 X-ray sources in the field of view, 42 of which are located within the optical confines of the galaxy. On the basis of X-ray colour classification and after correcting for background objects, we conclude that our source sample includes ~ 20 X-ray binaries, 5 supernova remnants and 7 very soft sources (including 2 good candidate supersoft sources) associated with NGC 55. Detailed spectral and timing analysis was carried out on 4 of the brightest X-ray sources. One of these objects is identified with a Galactic foreground star and is a possible new RS CVn system. The other three are consistent with accreting X-ray binaries, though further evidence of short term variability is required to confirm this. We also find evidence of an underlying component, which is concentrated on the bar region but has an extent of at least 6' (3 kpc) in the plane of the galaxy and +/- 1' (+/- 500 pc) perpendicular to it. This emission is best fitted by a thermal plasma plus power-law model but with high intrinsic absorption consistent with its location in the central disc of the galaxy. We interpret the soft component as diffuse thermal emission linked to regions of current star formation, whilst the hard power-law component may originate in unresolved X-ray binary sources. The intrinsic luminosity of this residual disc emission may exceed Lx ~ 6e38 ergs/s (0.3-6 keV). A comparison with other Magellanic systems confirms that, in terms of both its discrete X-ray source population and its extended emission, NGC 55 has X-ray properties which are typical of its class.
description: 17 pages, 8 figures, accepted for publication in MNRAS
Single-photon nonreciprocal excitation transfer with non-Markovian retarded effects
Creators: name: Du, Lei
name: Cai, Mao-Rui
name: Wu, Jin-Hui
name: Wang, Zhihai
name: Li, Yong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study at the single-photon level the nonreciprocal excitation transfer between emitters coupled with a common waveguide. Non-Markovian retarded effects are taken into account due to the large separation distance between different emitter-waveguide coupling ports. It is shown that the excitation transfer between the emitters of a small-atom dimer can be obviously nonreciprocal by introducing between them a coherent coupling channel with nontrivial coupling phase. We prove that for dimer models the nonreciprocity cannot coexist with the decoherence-free giant-atom structure although the latter markedly lengthens the lifetime of the emitters. In view of this, we further propose a giant-atom trimer which supports both nonreciprocal transfer (directional circulation) of the excitation and greatly lengthened lifetime. Such a trimer model also exhibits incommensurate emitter-waveguide entanglement for different initial states in which case the excitation transfer is however reciprocal. We believe that the proposals in this paper are of potential applications in large-scale quantum networks and quantum information processing.
description: 10 pages, 7 figures
Validation and parameter optimization of a hybrid embedded/homogenized solid tumor perfusion model
Creators: name: Kremheller, Johannes
name: Brandstaeter, Sebastian
name: Schrefler, Bernhard A.
name: Wall, Wolfgang A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: The goal of this paper is to investigate the validity of a hybrid embedded/homogenized in-silico approach for modeling perfusion through solid tumors. The rationale behind this novel idea is that only the larger blood vessels have to be explicitly resolved while the smaller scales of the vasculature are homogenized. As opposed to typical discrete or fully-resolved 1D-3D models, the required data can be obtained with in-vivo imaging techniques since the morphology of the smaller vessels is not necessary. By contrast, the larger vessels, whose topology and structure is attainable non-invasively, are resolved and embedded as one-dimensional inclusions into the three-dimensional tissue domain which is modeled as a porous medium. A sound mortar-type formulation is employed to couple the two representations of the vasculature. We validate the hybrid model and optimize its parameters by comparing its results to a corresponding fully-resolved model based on several well-defined metrics. These tests are performed on a complex data set of three different tumor types with heterogeneous vascular architectures. The correspondence of the hybrid model in terms of mean representative elementary volume blood and interstitial fluid pressures is excellent with relative errors of less than 4%. Larger, but less important and explicable errors are present in terms of blood flow in the smaller, homogenized vessels. We finally discuss and demonstrate how the hybrid model can be further improved to apply it for studies on tumor perfusion and the efficacy of drug delivery.
Compositional Reinforcement Learning from Logical Specifications
Creators: name: Jothimurugan, Kishor
name: Bansal, Suguman
name: Bastani, Osbert
name: Alur, Rajeev
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: We study the problem of learning control policies for complex tasks given by logical specifications. Recent approaches automatically generate a reward function from a given specification and use a suitable reinforcement learning algorithm to learn a policy that maximizes the expected reward. These approaches, however, scale poorly to complex tasks that require high-level planning. In this work, we develop a compositional learning approach, called DiRL, that interleaves high-level planning and reinforcement learning. First, DiRL encodes the specification as an abstract graph; intuitively, vertices and edges of the graph correspond to regions of the state space and simpler sub-tasks, respectively. Our approach then incorporates reinforcement learning to learn neural network policies for each edge (sub-task) within a Dijkstra-style planning algorithm to compute a high-level plan in the graph. An evaluation of the proposed approach on a set of challenging control benchmarks with continuous state and action spaces demonstrates that it outperforms state-of-the-art baselines.
The Monitor project: Searching for occultations in young open clusters
Creators: name: Aigrain, Suzanne
name: Hodgkin, Simon
name: Irwin, Jonathan
name: Hebb, Leslie
name: Irwin, Mike
name: Favata, Fabio
name: Moraux, Estelle
name: Pont, Frederic
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The Monitor project is a photometric monitoring survey of nine young (1-200Myr) clusters in the solar neighbourhood to search for eclipses by very low mass stars and brown dwarfs and for planetary transits in the light curves of cluster members. It began in the autumn of 2004 and uses several 2 to 4m telescopes worldwide. We aim to calibrate the relation between age, mass, radius and where possible luminosity, from the K-dwarf to the planet regime, in an age range where constraints on evolutionary models are currently very scarce. Any detection of an exoplanet in one of our youngest targets (<=10Myr) would also provide important constraints on planet formation and migration timescales and their relation to proto-planetary disc lifetimes. Finally, we will use the light curves of cluster members to study rotation and flaring in low-mass pre-main sequence stars. The present paper details the motivation, science goals and observing strategy of the survey. We present a method to estimate the sensitivity and number of detections expected in each cluster, using a simple semi-analytic approach which takes into account the characteristics of the cluster and photometric observations, using (tunable) best-guess assumptions for the incidence and parameter distribution of putative companions, and we incorporate the limits imposed by radial velocity follow-up from medium and large telescopes. We use these calculations to show that the survey as a whole can be expected to detect over 100 young low and very low mass eclipsing binaries, and approx. 3 transiting planets with radial velocity signatures detectable with currently available facilities.
description: 26 pages, 10 figures, to appear in MNRAS. A PDF with full resolution figures is available from http://www.ast.cam.ac.uk/~suz/publi/papers/monitor_intro_accepted.pdf
Flat bands by latent symmetry
Creators: name: Morfonios, C. V.
name: Röntgen, M.
name: Pyzh, M.
name: Schmelcher, P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Flat energy bands of model lattice Hamiltonians provide a key ingredient in designing dispersionless wave excitations and have become a versatile platform to study various aspects of interacting many-body systems. Their essential merit lies in hosting compactly localized eigenstates which originate from destructive interference induced by the lattice geometry, in turn often based on symmetry principles. We here show that flat bands can be generated from a hidden symmetry of the lattice unit cell, revealed as a permutation symmetry upon reduction of the cell over two sites governed by an effective dimer Hamiltonian. This so-called latent symmetry is intimately connected to a symmetry between possible walks of a particle along the cell sites, starting and ending on each of the effective dimer sites. The summed amplitudes of any eigenstate with odd parity on the effective dimer sites vanish on special site subsets called walk multiplets. We exploit this to construct flat bands by using a latently symmetric unit cell coupled into a lattice via walk multiplet interconnections. We demonstrate that the resulting flat bands are tunable by different parametrizations of the lattice Hamiltonian matrix elements which preserve the latent symmetry. The developed framework may offer fruitful perspectives to analyze and design flat band structures.
description: 14 pages (10 pages main text), 3 appendices, 9 figures
Impact of Central American Integration on U.S. Agricultural Exports
Creators: name: Kallemeyn, Norman R.
name: Kallemeyn, Norman R.
Publisher: name: Unknown
Year: 1967
Subjects: subject: Agricultural and Food Policy
subject: Crop Production/Industries
subject: International Relations/Trade
subject: Livestock Production/Industries
subject: Marketing
subject: FOS: Economics and business

description: Reprinted from: Foreign Agricultural Trade of the United States, February 1967
Manning the Fraser Canyon gold rush
Creators: name: Groeneveld-Meijer, Averill
Publisher: name: University of British Columbia
Year: 2009

description: In the canyon where the Fraser River flows through the Cascade mountains, migrating salmon supported a large, dense native population. By 1850 the Hudson’s Bay Company had several forts on other parts of the Fraser River and its tributaries but found the canyon itself inaccessible. Prior to the gold rush, whites rarely ventured there. Discoveries of gold in Fraser River in 1856 drew the attention of outsiders and a rush of miners, and led eventually to permanent white settlement on mainland British Columbia. Contrary to much historiography, these were not foregone results. Instead, the gold rush was a complex process of negotiation and conflict among competing groups as they sought to profit from gold discoveries. The Hudson’s Bay Company sought to gain and retain control of the resource by incorporating it into its trade and by excluding outsiders. But miners arrived by the thousands, and the Company was forced to try to regulate miners’ access to the resource. However, as a group, miners were cohesive and self-reliant; they had little need for outside intervention. The Hudson’s Bay Company was unable to regulate them while pursuing its own ideas of profit. The British government subsequently revoked the Hudson Bay Company’s trade license, and proclaimed British Columbia a colony. In efforts to impose its own ideals of order on the gold fields, the government introduced a new colonial administration which, following a chain of command extending from London through Victoria to the Fraser, sought to organize the population in the spaces of the Fraser Canyon. Government authority was reinforced by the legal system’s flexible responses to the diverse population’s activities it deemed illegal. By studying the interactions of natives, miners, traders, administrators, and the legal system, I have attempted to untangle the ways in which white men negotiated their particular racist and masculinist ideals and sought to impose them in the spaces of the Fraser Canyon.
Electron bound by a potential well in the presence of a constant uniform magnetic field
Creators: name: Khalilov, V. R.
name: Chibirova, F. Kh.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the effect of a constant uniform magnetic field on an electrically charged massive particle (an electron) bound by a potential well, which is described by means of a single attractive $λδ({\bf r})$ potential. A transcendental equation that determines the electron energy spectrum is derived and solved. The electron wave function in the ground (bound) state is approximately constructed in a remarkable simple form. It is shown that there arises the probability current in the bound state in the presence of a uniform constant magnetic field. This (electric) current, being by the gauge invariant quantity, must be observable and involve (and exercise influence on) the electron scattering. The probability current density resembles a stack of "pancake" vortices'' whose circulating "currents'' around the magnetic field direction ($z$-axes) are mostly confined within the plane $z=0$. We also compute the tunnelling probability of electron from the bound to free state under a weak constant homogeneous electric field, which is parallel to the magnetic field. The model under consideration is briefly discussed in two spatial dimensions.
description: 11 pages, 4 figures. Acknowledgements are rewritten
Renormalon subtraction in OPE using Fourier transform: Formulation and application to various observables
Creators: name: Hayashi, Yuuki
name: Sumino, Yukinari
name: Takaura, Hiromasa
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Properly separating and subtracting renormalons in the framework of the operator product expansion (OPE) is a way to realize high precision computation of QCD effects in high energy physics. We propose a new method (FTRS method), which enables to subtract multiple renormalons simultaneously from a general observable. It utilizes a property of Fourier transform, and the leading Wilson coefficient is written in a one-parameter integral form whose integrand has suppressed (or vanishing) renormalons. The renormalon subtraction scheme coincides with the usual principal-value prescription at large orders. We perform test analyses and subtract the ${\cal O}(Λ_{\rm QCD}^4)$ renormalon from the Adler function, the ${\cal O}(Λ_{\rm QCD}^2)$ renormalon from the $B\to X_ul\barν$ decay width, and the ${\cal O}(Λ_{\rm QCD})$ and ${\cal O}(Λ_{\rm QCD}^2)$ renormalons from the $B,\,D$ meson masses. The analyses show good consistency with theoretical expectations, such as improved convergence and scale dependence. In particular we obtain $\barΛ_{\rm FTRS}=0.495\pm0.053~\text{GeV}$ and$ (μ_π^2)_{\rm FTRS}=-0.12\pm 0.23~\text{GeV}^2$ for the non-perturbative parameters of HQET. We explain the formulation and analyses in detail.
description: 67 pages, 14 figures, More discussions, figures and references added in revision
Neutrino Cooled Disk and Its Stability
Creators: name: Kawanaka, Norita
name: Mineshige, Shin
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the structure and stability of hypercritical accretion flows around stellar-mass black holes, taking into account neutrino cooling, lepton conservation, and firstly a realistic equation of state in order to properly treat the dissociation of nuclei. We obtain the radial distributions of physical properties, such as density, temperature and electron fraction, for various mass accretion rates $0.1\sim 10M_{\odot}{\rm s}^{-1}$. We find that, depending on mass accretion rates, different physics affect considerably the structure of the disk; most important physics is (1) the photodissociation of nuclei around $r\sim 100r_g$ for relatively low mass accretion rates ($\dot{M}\sim 0.01-0.1M_{\odot} {\rm s}^{-1}$), (2) efficient neutrino cooling around $r\sim 10-100r_g$ for moderately high mass accretion rate ($\dot{M}\sim 0.2-1.0M_{\odot}{\rm s}^{-1}$), and (3) neutrino trapping ($r\sim 3-10r_g$) for very high mass accretion rate ($\dot{M}\gtrsim 2.0M_{\odot}{\rm s}^{-1}$). We also investigate the stability of hypercritical accretion flows by drawing the thermal equilibrium curves, and find that efficient neutrino cooling makes the accretion flows rather stable against both thermal and viscous modes.
description: 26 pages, 28 figures, Accepted for publication in ApJ
Coalescence of Andreev bound states on the surface of a chiral topological semimetal
Creators: name: Esin, V. D.
name: Barash, Yu. S.
name: Timonina, A. V.
name: Kolesnikov, N. N.
name: Deviatov, E. V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We experimentally investigate the magnetic field dependence of Andreev transport through a region of proximity-induced superconductivity in CoSi topological chiral semimetal. With increasing parallel to the CoSi surface magnetic field, the sharp subgap peaks, associated with Andreev bound states, move together to nearly-zero bias position, while there is only monotonous peaks suppression for normal to the surface fields. The zero-bias $dV/dI$ resistance value is perfectly stable with changing the in-plane magnetic field. As the effects are qualitatively similar for In and Nb superconducting leads, they reflect the properties of proximized CoSi surface. The Andreev states coalescence and stability of the zero-bias $dV/dI$ value with increasing in-plane magnetic field are interpreted as the joined effect of the strong SOC and the Zeeman interaction, known for proximized semiconductor nanowires. We associate the observed magnetic field anisotropy with the recently predicted in-plane polarized spin texture of the Fermi arcs surface states.
description: final version
Restoration of chiral and U(1)_A symmetries in excited hadrons in the semiclassical regime
Creators: name: Glozman, L. Ya.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Restoration of chiral and $U(1)_A$ symmetries in excited hadrons is reviewed. Implications of the OPE as well as of the semiclassical expansion for this phenomenon are discussed. A solvable model of the 't Hooft type in 3+1 dimensions is presented, which demonstrates a fast restoration of both chiral and $U(1)_A$ symmetries at larger spins and radial excitations.
description: 9 pp. Talk given at the seventh workshop "Continuous Advances in QCD 2006", Minneapolis, May 11-14, 2006
ShapeFit: extracting the power spectrum shape information in galaxy surveys beyond BAO and RSD
Creators: name: Brieden, Samuel
name: Gil-Marín, Héctor
name: Verde, Licia
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In the standard (classic) approach, galaxy clustering measurements from spectroscopic surveys are compressed into baryon acoustic oscillations and redshift space distortions measurements, which in turn can be compared to cosmological models. Recent works have shown that avoiding this intermediate step and fitting directly the full power spectrum signal (full modelling) leads to much tighter constraints on cosmological parameters. Here we show where this extra information is coming from and extend the classic approach with one additional effective parameter, such that it captures, effectively, the same amount of information as the full modelling approach, but in a model-independent way. We validate this new method (ShapeFit) on mock catalogs, and compare its performance to the full modelling approach finding both to deliver equivalent results. The ShapeFit extension of the classic approach promotes the standard analyses at the level of full modelling ones in terms of information content, with the advantages of i) being more model independent; ii) offering an understanding of the origin of the extra cosmological information; iii) allowing a robust control on the impact of observational systematics.
description: 60 pages, 19 figures, 5 Tables; v2 matches accepted version, new figures 7 and 9 and table 4, updated figures 1, 7 and 16
High Temperature Superconductivity - Magnetic Mechanisms
Creators: name: Norman, M. R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A brief history is offered concerning the relation of magnetism to superconductivity, and the possibility that magnetic correlations are responsible for certain types of superconductors. A central focus is on high temperature cuprate superconductivity and the important question of whether its d-wave pairing is caused by antiferromagnetic or singlet correlations. Connected with this question is the much debated relation of the pseudogap phase to the superconducting phase, and whether lattice degrees of freedom are relevant or not.
description: 34 pages, 16 figures, Contribution to the Handbook of Magnetism and Advanced Magnetic Materials, vol. 5, Wiley
Significant Inverse Magnetocaloric Effect induced by Quantum Criticality
Creators: name: Liu, Tao
name: Liu, Xin-Yang
name: Gao, Yuan
name: Jin, Hai
name: He, Jun
name: Sheng, Xian-Lei
name: Jin, Wentao
name: Chen, Ziyu
name: Li, Wei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The criticality-enhanced magnetocaloric effect (MCE) near a field-induced quantum critical point (QCP) in the spin systems constitutes a very promising and highly tunable alternative to conventional adiabatic demagnetization refrigeration. Strong fluctuations in the low-$T$ quantum critical regime can give rise to a large thermal entropy change and thus significant cooling effect when approaching the QCP. In this work, through efficient and accurate many-body calculations, we show there exists a significant inverse MCE(iMCE) in the spin-1 quantum chain materials(CH$_3$)$_4$NNi(NO$_2$)$_3$ (TMNIN) and NiCl$_2$-4SC(NH$_2$)$_2$ (DTN), where DTN has substantial low-$T$ refrigeration capacity while requiring only moderate magnetic fields. The iMCE characteristics, including the adiabatic temperature change $ΔT_{\rm ad}$, isothermal entropy change $ΔS$, differential Grüneisen parameter, and the entropy change rate, are obtained with quantum many-body calculations at finite temperature. The cooling performance, i.e., the efficiency factor and hold time, of the two compounds is also discussed. Based on the many-body calculations on realistic models for the spin-chain materials, we conclude that the compound DTN constitutes a very promising and highly efficient quantum magnetic coolant with pronounced iMCE properties. We advocate that such quantum magnets can be used in cryofree refrigeration for space applications and quantum computing environments.
description: 10 pages,9 figures,1 table
New periodic variable stars coincident with ROSAT sources discovered using SuperWASP
Creators: name: Norton, A. J.
name: Wheatley, P. J.
name: West, R. G.
name: Haswell, C. A.
name: Street, R. A.
name: Cameron, A. Collier
name: Christian, D. J.
name: Enoch, B.
name: Gallaway, M.
name: Hellier, C.
name: Horne, K.
name: Irwin, J.
name: Kane, S. R.
name: Lister, T. A.
name: Nicholas, J. P.
name: Parley, N.
name: Pollacco, D.
name: Ryans, R.
name: Skillen, I.
name: Wilson, D. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present optical lightcurves of 428 periodic variable stars coincident with ROSAT X-ray sources, detected using the first run of the SuperWASP photometric survey. Only 68 of these were previously recognised as periodic variables. A further 30 of these objects are previously known pre-main sequence stars, for which we detect a modulation period for the first time. Amongst the newly identified periodic variables, many appear to be close eclipsing binaries, their X-ray emission is presumably the result of RS CVn type behaviour. Others are probably BY Dra stars, pre-main sequence stars and other rapid rotators displaying enhanced coronal activity. A number of previously catalogued pulsating variables (RR Lyr stars and Cepheids) coincident with X-ray sources are also seen, but we show that these are likely to be misclassifications. We identify four objects which are probable low mass eclipsing binary stars, based on their very red colour and light curve morphology.
description: Accepted for publication in Astronomy & Astrophysics. This submission does not include Figure 1 (lightcurves & power spectra). The 107 panels of Figure 1 can be found online at http://physics.open.ac.uk/~ajnorton/wasp_rosat/
HANGING BY A THREAD: INVESTIGATING THE EFFECTS OF LOW TIDE TEMPERATURE ON MUSSEL ATTACHMENT STRENGTH
Creators: name: Oraha, Georget
Publisher: name: Zenodo
Year: 2021
Subjects: mussels
marine ecology
byssal threads
attachment strength

description: Mytilus californianus, the California mussel, is a foundation species and dominant space-holder in the rocky intertidal zone, an environment that goes through extreme temperature shifts on a daily basis as organisms are submerged in seawater during high tide and exposed to terrestrial conditions during low tide. Mussels create protein ‘anchors’ called byssal threads that allow them to attach to rocks and each other. To my knowledge, no studies have addressed the role of temperature during low tide on attachment strength of mussels, despite the clear importance of this topic in the context of the rising temperatures predicted with a changing climate. I used laboratory manipulations to investigate how temperature during low tide and the number of low-tide exposures affected three components of mussel attachment: byssal thread production, individual mussel attachment strength, and single byssal thread thickness (as a proxy for strength). We collected mussels from sites in Washington and California and set up a five-day lab experiment with two types of treatments: number of low tide exposures (exposure on the first day followed by four days of submersion or exposure each day for five days) and temperature during low tide exposure (ambient or elevated temperature). Overall, neither number of low tides nor low tide temperature affected the number of byssal threads produced by mussels, but the number of low tides had strong effects on the amount of force required to remove mussels from the substratum and on the thickness of individual byssal threads (a proxy for thread strength). Mussels exposed to multiple low tides required less force to remove from the substratum and had thinner (and thus weaker) threads than mussels exposed to a single low tide, and the combination of multiple low tides and warm low tide temperatures had negative impacts on mussel attachment. In the context of a changing climate, these data help us to understand important hurdles to persistence for this ecosystem engineer.
Time-reversible Born-Oppenheimer molecular dynamics
Creators: name: Niklasson, Anders M. N.
name: Tymczak, C. J.
name: Challacombe, Matt
Publisher: name: arXiv
Year: 2006
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a time-reversible Born-Oppenheimer molecular dynamics scheme, based on self-consistent Hartree-Fock or density functional theory, where both the nuclear and the electronic degrees of freedom are propagated in time. We show how a time-reversible adiabatic propagation of the electronic degrees of freedom is possible despite the non-linearity and incompleteness of the self-consistent field procedure. Time-reversal symmetry excludes a systematic long-term energy drift for a microcanonical ensemble and the number of self-consistency cycles can be kept low (often only 2-4 cycles per nuclear time step) thanks to a good initial guess given by the adiabatic propagation of the electronic degrees of freedom. The time-reversible Born-Oppenheimer molecular dynamics scheme therefore combines a low computational cost with a physically correct time-reversible representation of the dynamics, which preserves a detailed balance between propagation forwards and backwards in time.
description: 4 pages, 4 figures