cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Geology and thermal history of an area near Okanagan Lake, Southern British Columbia
Creators: name: Medford, Gary Allen
Publisher: name: University of British Columbia
Year: 2010

description: Five phases of deformation are recognized in Shuswap (Monashee Group) gneiss in an area east of Okanagan Lake, southern British Columbia. The first is delineated by north trending mesoscopic structures. The second comprises a south closing megascopic synform with a horizontal ESE axial direction. This structure has in turn been coaxially refolded into a more open phase 3 synform. The second deformation was associated with extensive introduction of synkinematic quartz monzonite and granodiorite that comprises much of the area, and culminated with amphibolite grade metamorphism. Phase 3 deformation was followed by extensive local recrystal1ization and metasomatism which destroyed earlier fabric elements of the gneisses. Phases 1 to 3 are pre-mid-Carboniferous based on poor fossil evidence whereas phases 4 and 5 are Tertiary. Phase 4 comprises open flexural slip folding about NE trending axes and Phase 5 consists of broad warps about horizontal ESE axes. These deformational events were associated with high level thermal and hydrothermal activity which appears to be most intense in areas of high grade Shuswap gneiss, where it has reset K-Ar dates to about 50 million years (paper no. 1). Thermally sensitive fission track apatite dates indicate that the high thermal gradients can be traced into the plutonic rocks west of the Okanagan Valley in which K-Ar dates have been much less affected and range between 130 and 200 million years. Thus perhaps only the oldest dates represent minimum emplacement dates. The statistical methods used in acquiring the apatite dates are discussed and developed beyond that available in the literature (paper no. 2).
Vector and scalar form factors for K- and D-meson semileptonic decays from twisted mass fermions with Nf = 2
Creators: name: Di Vita, S.
name: Haas, B.
name: Mescia, F.
name: Lubicz, V.
name: Simula, S.
name: Tarantino, C.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We present lattice results for the form factors relevant in the K -> pion and D -> pion semileptonic decays, obtained from simulations with two flavors of dynamical twisted-mass fermions and pion masses as light as 260 MeV. For K -> pion decays we discuss the estimates of the main sources of systematic uncertainties, including the quenching of the strange quark, leading to our final result f+(0) = 0.9560 (57) (62). Combined with the latest experimental data, our value of f+(0) implies for the CKM matrix element |Vus| the value 0.2267 (5) (20) consistent with the first-row CKM unitarity. For D -> pion decays the application of Heavy Meson Chiral Perturbation Theory allows to extrapolate our results for both the scalar and the vector form factors at the physical point with quite good accuracy, obtaining a nice agreement with the experimental data. In particular at zero-momentum transfer we obtain f+(0) = 0.64 (5).
description: 8 pages, 4 figures, 1 table, proceedings of the XXVII Int'l Symposium on Lattice Field Theory (LAT2009), July 26-31 2009, Peking University, Beijing (China)
title: Mapping the Way Forward : Spatial Data Inventory and Insights for Marine Planning in the US Virgin Islands
Creators: name: Wright, Jennifer
name: Wilson, Rich
name: Wylie, Meagan
name: Rule, Erica
name: Walter, John F. III
name: Hendon, Read
name: Morris, James
Publisher: name: NOAA National Centers for Coastal Ocean Science
publisherIdentifier: https://ror.org/05ba43f71
publisherIdentifierScheme: ROR
Year: 2023

description: NOAA technical memorandum NOS NCCOS ; 325
description: NOAA technical memorandum NMFS-SEFSC ; 776
description: NCCOS and NMFS SEFSC are working to build spatial planning capacity in the US Caribbean region. Marine spatial planning, especially for insular communities like the USVI and Puerto Rico, holds great promise to assist coastal managers, environmental organizations, and industry with planning for future development of the blue economy, including emerging opportunities like renewable energy and aquaculture.
Screening people with diabetes for atrial fibrillation.
Creators: name: Hall, Angela
Publisher: name: Lancaster University
Year: 2023

description: Thesis by alternative route comprising four independent yet related studies exploring the relationship between diabetes and atrial fibrillation and whether screening people with diabetes for this common heart rhythm disorder, would be valuable. A systematic review critiques the utility, effectiveness and feasibility of the AliveCor screening application, demonstrating this as a valid and effective tool for this purpose. A screening study then demonstrates a higher prevalence of atrial fibrillation in people with diabetes, also showing statistical significance that increasing age, is a predictor for developing atrial fibrillation in this population. Another study then considers the quality of life study in people with atrial fibrillation and then people with atrial fibrillation and diabetes, showing the quality of life to be poorer in the majority of assessed domains, when both conditions coexist. Lastly, a qualitative interview study considers the views and experiences of people screened in the earlier study, demonstrating variable understanding around atrial fibrillation and views around how, when and who to screen.
Dust continuum, CO, and [C I] 1-0 lines: self-consistent H2 mass estimates and the possibility of globally CO-dark galaxies at $z = 0.35$
Creators: name: Dunne, L.
name: Maddox, S. J.
name: Vlahakis, C.
name: Gomez, H. L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present ALMA observations of a small but statistically complete sample of twelve 250 micron selected galaxies at $z=0.35$ designed to measure their dust submillimeter continuum emission as well as their CO(1-0) and atomic carbon [CI](3P1-3P0) spectral lines. This is the first sample of galaxies with global measures of all three $H_2$-mass tracers and which show star formation rates (4-26 Msun yr$^{-1}$) and infra-red luminosities ($1-6\times10^{11}$ Lsun) typical of star forming galaxies in their era. We find a surprising diversity of morphology and kinematic structure; one-third of the sample have evidence for interaction with nearby smaller galaxies, several sources have disjoint dust and gas morphology. Moreover two galaxies have very high $L_{CI}/L_{CO}$ ratios for their global molecular gas reservoirs; if confirmed, such extreme intensity ratios in a sample of dust selected, massive star forming galaxies presents a challenge to our understanding of ISM. Finally, we use the emission of the three molecular gas tracers, to determine the carbon abundance, $X_{ci}$, and CO-$\rm{H_2}$ conversion $α_{co}$ in our sample, using a weak prior that the gas-to-dust ratio is similar to that of the Milky Way for these massive and metal rich galaxies. Using a likelihood method which simultaneously uses all three gas tracer measurements, we find mean values and errors on the mean of $α_{co}=3.0\pm0.5\,\rm{Msun\,(K\,kms^{-1}\,pc^2)^{-1}}$ and $X_{ci}=1.6\pm0.1\times 10^{-5}$ (or $α_{ci}=18.8\,K kms^{-1}\,pc^2 (Msun)^{-1}$) and $δ_{GDR}=128\pm16$ (or $α_{850}=5.9\times10^{12}\,\rm{W\,Hz^{-1}\, Msun^{-1}}$), where our starting assumption is that these metal rich galaxies have an average gas-to-dust ratio similar to that of the Milky Way centered on $δ_{GDR}=135$.
description: 34 pages, published in MNRAS
The Effective Actions of Pseudoscalar and Scalar Particles in Theories with Gauge and Conformal Anomalies
Creators: name: Armillis, Roberta
name: Coriano, Claudio
name: Rose, Luigi Delle
name: Guzzi, Marco
name: Mariano, Antonio
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We review recent work on the effective field theory description and the phenomenology of axion-like and scalar particles in models characterized by gauge and/or conformal anomalies.
description: Presented by C. Coriano at the 9th Hellenic Workshop on Elementary Particle Physics and Gravity, Corfu Summer Institute, Greece August 30 September 20, 2009
One-loop approximation of Moller scattering in Krein-space quantization
Creators: name: Payandeh, F.
name: Mehrafarin, M.
name: Takook, M. V.
Publisher: name: arXiv
Year: 2009
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: It has been shown that the negative-norm states necessarily appear in a covariant quantization of the free minimally coupled scalar field in de Sitter spacetime [1,2]. In this processes ultraviolet and infrared divergences have been automatically eliminated [3]. A natural renormalization of the one-loop interacting quantum field in Minkowski spacetime ($λϕ^4$) has been achieved through the consideration of the negative-norm states defined in Krein space. It has been shown that the combination of quantum field theory in Krein space together with consideration of quantum metric fluctuation, results in quantum field theory without any divergences [4]. Pursuing this approach, we express Wick's theorem and calculate Møller scattering in the one-loop approximation in Krein space. The mathematical consequence of this method is the disappearance of the ultraviolet divergence in the one-loop approximation.
description: 10 pages
Appendix from Early intervention is the key to success in COVID-19 control
Creators: name: Binny, Rachelle N.
name: Baker, Michael G.
name: Hendy, Shaun C.
name: James, Alex
name: Lustig, Audrey
name: Plank, Michael J.
name: Ridings, Kannan M.
name: Steyn, Nicholas
Publisher: name: The Royal Society
Year: 2021
Subjects: subject: Health Care
subject: Diseases
subject: 111706 Epidemiology
subject: FOS: Health sciences
subject: 10299 Applied Mathematics not elsewhere classified
subject: FOS: Mathematics

description: Model specification and supplementary tables (model parameters, sensitivity analyses and summary of restrictions under New Zealand's Alert Levels 3 and 4)
On the Origin of Exponential Galaxy Disks
Creators: name: Dutton, Aaron A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We use a disk galaxy evolution model to investigate whether galaxies with exponential surface brightness profiles can be produced in a cosmologically motivated framework for disk galaxy formation. Our model follows the accretion, cooling, and ejection of baryonic mass, as a function of radius, inside growing dark matter haloes. The surface density profile of the disk is determined by detailed angular momentum conservation, starting from the distribution of specific angular momentum as found in cosmological simulations. Exponential and quasi-exponential disks can be produced by our model through a combination of supernova driven galactic outflows (which preferentially remove low angular momentum material), intrinsic variation in the angular momentum distribution of the halo gas, and the inefficiency of star formation at large radii. We use observations from the SDSS NYU-VAGC to show that the median Sersic index of blue galaxies is a strong function of stellar mass. For blue galaxies, low mass galaxies have a median n=1.3, while high mass galaxies have a median n=4. Our model with energy driven outflows correctly reproduces this trend, whereas our models with momentum driven outflows and no outflows over predict the Sersic indices in low mass galaxies. We show that the observed fraction of "bulge-less" exponential galaxies is a strong function of stellar mass. For Milky-Way mass galaxies less than 0.1% of blue galaxies are bulge-less, whereas for M33 mass galaxies bulge-less and quasi-bulgeless galaxies are typical. These results suggest that the difficulty of hierarchical formation models to produce bulge-less Milky-Way mass galaxies is in fact not a problem. However, the problem of producing M33 like galaxies remains, and will provide a key test for hierarchical galaxy formation models. [Abridged]
description: 23 pages, 13 figures, accepted to MNRAS, two new figures
A Concrete Estimate For The Weak Poincare Inequality On Loop Space
Creators: name: Chen, Xin
name: Li, Xue-Mei
name: Wu, Bo
Publisher: name: arXiv
Year: 2009
Subjects: subject: Probability (math.PR)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 60H07, 46G99

description: The aim of the paper is to study the pinned Wiener measure on the loop space over a simply connected compact Riemannian manifold together with the Hilbert space structure induced by Mallianvin calculus and the induced Ornstein- Uhlenbeck operator. We give a concrete estimate for the weak Poincare inequality for the O-U Dirichlet form on loop space over simply connected compact Riemannian manifold with strict positive Ricci curvature.
Dehn surgeries on knots in product manifolds
Creators: name: Ni, Yi
Publisher: name: arXiv
Year: 2010
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 57M99; 57R30

description: We show that if a surgery on a knot in a product sutured manifold yields the same product sutured manifold, then this knot is a 0-- or 1--crossing knot. The proof uses techniques from sutured manifold theory.
description: 21 pages, 5 figures
Catálogo de Colección Nacional de Academia Salvadoreña de la Historia
Creators: name: Hernández Gutierrez, Kevin Amilcar
name: Girón Aguilar, Nimrod Edgardo
name: Beltrán, Karla Gabriela
Publisher: name: Zenodo
Year: 2020
Subjects: Catálogo
Catalogación
Compilación bibliográfica
Instrumento de búsqueda en archivos
Registro de archivos
Inventario
Análisis documental

description: El presente catálogo es una recopilación y consumación de todo el acervo bibliográfico perteneciente a la colección nacional de la cual es poseedora la Academia Salvadoreña de la Historia, en ella se encuentran conglomerados una cantidad de 1185 libros que a su vez por su antigüedad poseen un valor histórico. Por ello, este catálogo, tras meses de trabajo dentro del campo de la bibliotecología, se ha consumado una de las colecciones más importantes, la cual cabe destacar es la más consultada por estudiantes, docentes, investigadores y todas aquellas personas interesadas en el ámbito histórico.
STUDYING THE BIOCHEMICAL COMPOSITION AND QUALITY INDICATORS OF RASPBERIES DURING STORAGE IN REFRIGERATED WAREHOUSES
Creators: name: Ortikboev, Nurmukhammad
name: Safarov, Askarbek
Publisher: name: Zenodo
Year: 2023

description: In this article, changes in quality indicators and biochemical composition of berries during storage of Polka, Progress, Sugana, and Laszka varieties of raspberries in a refrigerated warehouse are studied. The article analyzed the berry weight, size, sugar content, dry matter content, berry moisture content, berry temperature, and pH indicators of raspberry.
Charm and charmonium-like spectroscopy in B decays in Belle
Creators: name: Aushev, T.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We report measurements of the branching fractions for the decays B->D_s1(2536)+ anti-D(*), where anti-D(*) is anti-D0, D- or D*-, and study of B->X(3872) K with X(3872) decaying to D*0 anti-D0 using a sample of 657 million B anti-B pairs recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.
description: 3 pages, 2 figures, proceedings for PANIC'08 conference
Non-markovian global persistence in phase-ordering kinetics
Creators: name: Henkel, Malte
name: Pleimling, Michel
Publisher: name: arXiv
Year: 2009
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The persistence probability P_g(t) of the global order-parameter of a simple ferromagnet undergoing phase-ordering kinetics after a quench from a fully disordered state to below the critical temperature, T
description: Latex2e, 9 pages with 2 figures included, final version
On the evolution of vortex in locally isothermal self-gravitating discs: a parameter study
Creators: name: Tarczay-Nehéz, D.
name: Rozgonyi, K.
name: Regály, Zs.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Gas rich dusty circumstellar discs observed around young stellar objects are believed to be the birthplace of planets and planetary systems. Recent observations revealed that large-scale horseshoe-like brightness asymmetries are present in dozens of transitional protoplanetary discs. Theoretical studies suggest that these brightness asymmetries bf could be caused by large-scale anticyclonic vortices triggered by the Rossby Wave Instability (RWI), which can be excited at the edges of the accretionally inactive region, the dead zone edge. Since vortices may play a key role in planet formation, investigating the conditions of the onset of RWI and the long-term evolution of vortices is inevitable. The aim of our work was to explore the effect of disc geometry (the vertical thickness of the disc), viscosity, the width of the transition region at the dead zone edge, and the disc mass on the onset, lifetime, strength and evolution of vortices formed in the disc. We performed a parametric study assuming different properties for the disc and the viscosity transition by running 1980 2D hydrodynamic simulations in the locally isothermal assumption with disc self-gravity included. Our results revealed that long-lived, large-scale vortex formation favours a shallow surface density slope and low- or moderate disc masses with Toomre $Q \lesssim 1/h$, where $h$ is the geometric aspect ratio of the disc. In general, in low viscosity models, stronger vortices form. However, rapid vortex decay and re-formation is more widespread in these discs.
description: 20 pages, 20 figs., 3 tables. Accepted to MNRAS
Quaternary geology : Coquitlam-Port Moody area, British Columbia
Creators: name: Hicock, Stephen Robert
Publisher: name: University of British Columbia
Year: 2010

description: During Quaternary time the Coquitlam-Port Moody area underwent two and possibly three major glaciations separated by nonglacial intervals. Each glaciation was accompanied by eustatic and isostatic sea-level changes of up to 230 m, relative to present sea level, and probably some tectonic adjustment. Associated with each major ice advance were two or three local ice advances represented by tills separated by outwash deposits. During the last major glaciation (Fraser), two stades occurred (Vashon and Coquitlam), possibly separated by an interstade (Quadra). The Coquitlam Stade was the earliest and is represented by the Coquitlam Drift (between 25,000 and 21,600 radiocarbon yr. B.P.) which has not been recognized before on the B.C. mainland; it may correlate with the Evans Creek Stade discovered in northwestern Washington. Nine formational lithostratigraphic units are mapped and described for-the area, each probably representing a geologic-climatic unit. The units are separated by unconformities representing three-dimensional irregular buried landscapes which were reshaped and replaced by new ones. Consequently, the Quaternary stratigraphy is extremely complex and sediment units occur sporadically. Correlations based on other than a three-dimensional study are at best tentative and must be supported by radiocarbon dates. The topography of the area was developed before Semiahmoo? time (>62,000 radiocarbon yr. B.P.) and has remained basically the same since then. Large gravel reserves occur in the area, many of them buried in uplands and in the sediment fill occupying the lower Coquitlam River valley. Outwash gravels are the most extensive of the four types found in the area and Vashon outwash is the most commonly mined. Buried landscapes make pit run reserve estimation very difficult, and municipal zoning regulations are phasing out gravel operations and covering valuable reserves with urban and industrial subdivisions.
Extended navigability of small world networks: exact results and new insights
Creators: name: Cartozo, Cecile Caretta
name: Rios, Paolo De Los
Publisher: name: arXiv
Year: 2009
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Navigability of networks, that is the ability to find any given destination vertex starting from any other vertex, is crucial to their usefulness. In 2000 Kleinberg showed that optimal navigability could be achieved in small-world networks provided that a special recipe was used to establish long range connections, and that a greedy algorithm, that ensures that the destination will be reached, is used. Here we provide an exact solution for the asymptotic behavior of such a greedy algorithm as a function of the system's parameters. Our solution enables us to show that the original claim that only a very special construction is optimal can be relaxed depending on further criteria, such as, for example, cost minimization, that must be satisfied.
description: Presented at the BCNet Workshop in Barcelona on December 12 2008; submitted to PRL
Climate Smart Agriculture Options for Myanmar Small-Holder Farmers: Education and Training Posters for Villages (Chin Language)
Creators: name: Myae, Chan
name: Noe, Su Myat
name: Barbon, Wilson John
name: Gonsalves, Julian
Publisher: name: Zenodo
Year: 2020
Subjects: climate change
smallholder agriculture
Climate-Smart Villages
Myanmar
climate smart agriculture

description: A series of educational posters promoting various climate-smart agriculture options, such as: boundary planting of green leaf manure trees; integration of perennial fruit trees; legumes and cover cropping; homestead production; improving seeds quality through better management and storage; backyard native pig farming; backyard native chicken farming; small scale goat rearing; small scale aquaculture for diversification; and promoting gender equality in agriculture in the climate smart villages. This set is translated into the Chin language for Myanmar.
Leptogenesis in Complex Hybrid Inflation
Creators: name: Prieto, Carlos Martinez
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the transference of an initial leptonic charge contained in a complex scalar field (waterfall field) at the end of the inflation to the leptons of the standard model and then convert this leptonic charge in baryonic charge by sphaleron process. The proposal is that this is done trough the decay of the complex scalar field particles into the right-handed neutrino which in turn decays into the left-handed lepton doublet and the Higgs field of the standard model. It must be analyzed in what environment the transference is done. We propose that the inflaton (the dominant energy density of the universe) decay into ultrarelativistic fermions before the waterfall field particles decay in the right-handed neutrino, leaving a thermalized bath where the transference of the leptonic asymmetry can be achieved.
description: 8 pages, 1 figure. Prepared for the AIP Conference Proceedings of the III International Meeting on Gravitation and Cosmology, Morelia, Mexico, May 26-30, 2008
Spatio-temporal modelling of extreme temperature events on the Greenland ice sheet
Creators: name: Clarkson, Daniel
Publisher: name: Lancaster University
Year: 2023
Subjects: Extreme value analysis
Gaussian process
Mixture modelling
Greenland Ice Sheet

description: The Greenland ice sheet has experienced significant melt over the past six decades, with rare extreme melt events covering large areas of the ice sheet. Melt events are typically analysed using summary statistics from satellite data, but the nature and characteristics of the events themselves are less frequently analysed. In this thesis, we take MODIS satellite temperature data and develop a series of models to build a detailed understanding of temperature, melt, and extreme temperature events on the ice sheet. A core aim of the modelling work is to create and use models that are statistically robust that also strongly consider the scientific context of the variables and processes being modelled. We first develop a statistical model for temperatures at a single location on the ice sheet. We define a novel method of identifying melt observations using a Gaussian mixture model to capture the distribution of temperatures across the ice sheet in a consistent format. In the next chapter, we begin to examine the spatial trends in the data by examining the mixture model’s parameters in a spatial setting. We use a regression model to predict the mixture model parameters for a given location based only on geographic spatial variables, allowing us to estimate the distribution of temperatures for any location using only a set of coordinates and information derived from them. We then examine spatial dependence between locations using a Gaussian process. Using the mixture model as a marginal model and insights from the regression model, we quantify the spatial dependence in the data and simulate temperature realisations for the entire ice sheet. Finally, we use the spatial conditional extremes model to model extreme temperature events. Using the model, we can describe the characteristics of extreme temperature events and simulate and predict them.
Surrogate-Assisted Genetic Algorithm for Wrapper Feature Selection
Creators: name: Altarabichi, Mohammed Ghaith
name: Nowaczyk, Sławomir
name: Pashami, Sepideh
name: Mashhad, Peyman Sheikholharam
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: Feature selection is an intractable problem, therefore practical algorithms often trade off the solution accuracy against the computation time. In this paper, we propose a novel multi-stage feature selection framework utilizing multiple levels of approximations, or surrogates. Such a framework allows for using wrapper approaches in a much more computationally efficient way, significantly increasing the quality of feature selection solutions achievable, especially on large datasets. We design and evaluate a Surrogate-Assisted Genetic Algorithm (SAGA) which utilizes this concept to guide the evolutionary search during the early phase of exploration. SAGA only switches to evaluating the original function at the final exploitation phase. We prove that the run-time upper bound of SAGA surrogate-assisted stage is at worse equal to the wrapper GA, and it scales better for induction algorithms of high order of complexity in number of instances. We demonstrate, using 14 datasets from the UCI ML repository, that in practice SAGA significantly reduces the computation time compared to a baseline wrapper Genetic Algorithm (GA), while converging to solutions of significantly higher accuracy. Our experiments show that SAGA can arrive at near-optimal solutions three times faster than a wrapper GA, on average. We also showcase the importance of evolution control approach designed to prevent surrogates from misleading the evolutionary search towards false optima.
Deneb's Variability as Viewed by BRITE Constellation and the Solar Mass Ejection Imager
Creators: name: Guzik, Joyce A.
Publisher: name: Zenodo
Year: 2024

description: Deneb, the prototype alpha Cygni variable, is a bright A2 Ia supergiant that shows irregular variability, presumed to be pulsations, with a 12-day quasi-period. Analyses of radial velocity and photometry data from 1930 to the present (Abt et al. PASP 2023; Guzik et al. 112th Annual AAVSO meeting 2023) suggested that larger amplitude 12-day variations appear to resume abruptly and at an arbitrary phase, and damp out after several cycles, with an interval of around 70 days between these resumptions. The photometric data included observations from the ground-based campaign of Richardson et al. (2011) taken between 1997 and 2001, data from the American Association of Variable Star Observers database (Kloppenborg, AAVSO, 2023) taken between 2021 and 2023, and three 27-day sector observations by the TESS spacecraft. These analyses raised several unanswered questions, among them: How exact and regular is the apparent time interval of ~70 days between resumption of higher amplitude pulsations with period ~12 days? Do these higher amplitude pulsation resumptions occur abruptly at an arbitrary phase in the pulsation cycle? For the above-mentioned data sets, the time between data points was too long, or the time series was too short to answer these questions definitively. However, we have begun analysis of an 8.6-year photometric data set from the Solar Mass Ejection Imager taken between 2003 and 2011, with cadence 1.7 hours. We will also examine BRITE data for Deneb, taken June-November 2014 and June-November 2015. We hope that these studies will answer the questions raised, and lead to a better understanding of the origin of the variability and the evolutionary state of Deneb and the alpha Cyg variables.
A microscopic model for current-induced switching of magnetization for half-metallic leads
Creators: name: Sandschneider, N.
name: Nolting, W.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the behaviour of the magnetization in a half-metallic ferromagnet/nonmagnetic insulator/ferromagnetic metal/paramagnetic metal (FM1/NI/FM2/PM) tunnel junction. It is calculated self-consistently within the nonequilibrium Keldysh formalism. The magnetic regions are treated as band ferromagnets and are described by the single-band Hubbard model. We developed a nonequilibrium spectral density approach to solve the Hubbard model approximately in the switching magnet. By applying a voltage to the junction it is possible to switch between antiparallel (AP) and parallel (P) alignment of the magnetizations of the two ferromagnets. The transition from AP to P occurs for positive voltages while the inverse transition from P to AP can be induced by negative voltages only. This behaviour is in agreement with the Slonczewski model of current-induced switching and appears self-consistently within the model, i.e. without using half-classical methods like the Landau-Lifshitz-Gilbert equation.
description: accepted for publication in PRB
The non-linear q-voter model
Creators: name: Castellano, C.
name: Munoz, M. A.
name: Pastor-Satorras, R.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We introduce a non-linear variant of the voter model, the q-voter model, in which q neighbors (with possible repetition) are consulted for a voter to change opinion. If the q neighbors agree, the voter takes their opinion; if they do not have an unanimous opinion, still a voter can flip its state with probability $ε$. We solve the model on a fully connected network (i.e. in mean-field) and compute the exit probability as well as the average time to reach consensus. We analyze the results in the perspective of a recently proposed Langevin equation aimed at describing generic phase transitions in systems with two ($Z_2$ symmetric) absorbing states. We find that in mean-field the q-voter model exhibits a disordered phase for high $ε$ and an ordered one for low $ε$ with three possible ways to go from one to the other: (i) a unique (generalized voter-like) transition, (ii) a series of two consecutive Ising-like and directed percolation transition, and (iii) a series of two transitions, including an intermediate regime in which the final state depends on initial conditions. This third (so far unexplored) scenario, in which a new type of ordering dynamics emerges, is rationalized and found to be specific of mean-field, i.e. fluctuations are explicitly shown to wash it out in spatially extended systems.
description: 9 pages, 7 figures
Cross-lingual Low Resource Speaker Adaptation Using Phonological Features
Creators: name: Maniati, Georgia
name: Ellinas, Nikolaos
name: Markopoulos, Konstantinos
name: Vamvoukakis, Georgios
name: Sung, June Sig
name: Park, Hyoungmin
name: Chalamandaris, Aimilios
name: Tsiakoulis, Pirros
Publisher: name: arXiv
Year: 2021
Subjects: subject: Sound (cs.SD)
subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The idea of using phonological features instead of phonemes as input to sequence-to-sequence TTS has been recently proposed for zero-shot multilingual speech synthesis. This approach is useful for code-switching, as it facilitates the seamless uttering of foreign text embedded in a stream of native text. In our work, we train a language-agnostic multispeaker model conditioned on a set of phonologically derived features common across different languages, with the goal of achieving cross-lingual speaker adaptation. We first experiment with the effect of language phonological similarity on cross-lingual TTS of several source-target language combinations. Subsequently, we fine-tune the model with very limited data of a new speaker's voice in either a seen or an unseen language, and achieve synthetic speech of equal quality, while preserving the target speaker's identity. With as few as 32 and 8 utterances of target speaker data, we obtain high speaker similarity scores and naturalness comparable to the corresponding literature. In the extreme case of only 2 available adaptation utterances, we find that our model behaves as a few-shot learner, as the performance is similar in both the seen and unseen adaptation language scenarios.
description: Proceedings of INTERSPEECH 2021
ds01.zip
Creators: name: White, Oliver
Publisher: name: figshare
Year: 2021
Subjects: Uncategorized

description: ArcGIS shape files and auxiliary files for the eight mapped tectonic systems, the depressions of the ridge-trough system, the boundary of Sputnik Planitia, and the approximate topographic rim of the Sputnik basin (as shown in Figs. 1 and 2 of the paper).
Leading twist nuclear shadowing, nuclear generalized parton distributions and nuclear DVCS at small x
Creators: name: Goeke, K.
name: Guzey, V.
name: Siddikov, M.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We generalize the leading twist theory of nuclear shadowing and calculate quark and gluon generalized parton distributions (GPDs) of spinless nuclei. We predict very large nuclear shadowing for nuclear GPDs. In the limit of the purely transverse momentum transfer, our nuclear GPDs become impact-parameter-dependent nuclear parton distributions (PDFs). Nuclear shadowing induces nontrivial correlations between the impact parameter b and the light-cone fraction x. We make predictions for the deeply virtual Compton scattering (DVCS) amplitude and the DVCS cross section on Pb-208 at high energies. We calculate the cross section of the Bethe-Heitler (BH) process and address the issue of the extraction of the DVCS signal from the e A \to e γA cross section. We find that the e A \to e γA differential cross section is dominated by DVCS at the momentum transfer t near the minima of the nuclear form factor. We also find that nuclear shadowing leads to dramatic oscillations of the DVCS beam-spin asymmetry, A_{LU}, as a function of t. The position of the points where A_{LU} changes sign is directly related to the magnitude of nuclear shadowing.
description: 37 pages, 12 figures. Matches the published version, Phys. Rev. 79, 035210 (2009)
Implied Correlation for Pricing multi-FX options
Creators: name: Shevchenko, Pavel V.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Pricing of Securities (q-fin.PR)
subject: FOS: Economics and business

description: Option written on several foreign exchange rates (FXRs) depends on correlation between the rates. To evaluate the option, historical estimates for correlations can be used but usually they are not stable. More significantly, pricing of the option using these estimates is usually inconsistent to the traded vanilla contracts. To price options written on several FXRs with the same denominating currency, financial practitioners and traders often use implied correlations calculated from implied volatilities of FXRs that form "currency triangles". However, some options may have underlying FXRs with different denominating currencies. In this paper, we present the formula for the implied correlations between such FXRs. These can be used for valuation, for example, barrier option on two FXRs with different denominating currencies where one FXR determines how much the option is in or out of the money at maturity while another FXR is related to the barrier. Other relevant options are straightforward.
LeMMINGs IV: The X-ray properties of a statistically-complete sample of the nuclei in active and inactive galaxies from the Palomar sample
Creators: name: Williams, D. R. A.
name: Pahari, M.
name: Baldi, R. D.
name: McHardy, I. M.
name: Mathur, S.
name: Beswick, R. J.
name: Beri, A.
name: Boorman, P.
name: Aalto, S.
name: Alberdi, A.
name: Argo, M. K.
name: Dullo, B. T.
name: Fenech, D. M.
name: Green, D. A.
name: Knapen, J. H.
name: Martí-Vidal, I.
name: Moldon, J.
name: Mundell, C. G.
name: Muxlow, T. W. B.
name: Panessa, F.
name: Pérez-Torres, M.
name: Saikia, P.
name: Shankar, F.
name: Stevens, I. R.
name: Uttley, P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: All 280 of the statistically-complete Palomar sample of nearby (<120 Mpc) galaxies dec > 20 degrees have been observed at 1.5 GHz as part of the LeMMINGs e-MERLIN legacy survey. Here, we present Chandra X-ray observations of the nuclei of 213 of these galaxies, including a statistically-complete sub-set of 113 galaxies in the declination range 40 degrees to 65 degrees. We observed galaxies of all optical spectral types, including 'active' galaxies (e.g., LINERs and Seyferts) and 'inactive' galaxies like HII galaxies and absorption line galaxies (ALG). The X-ray flux limit of our survey is 1.65$\times$10$^{-14}$~erg s$^{-1}$ cm$^{-2}$ (0.3$-$10 keV). We detect X-ray emission coincident within 2-arcsec of the nucleus in 150/213 galaxies, including 13/14 Seyferts, 68/77 LINERs, 13/22 ALGs and 56/100 HII galaxies, but cannot completely rule out contamination from non-AGN processes in sources with nuclear luminosities <10$^{39}$ erg s$^{-1}$. We construct an X-ray Luminosity function (XLF) and find that the local galaxy XLF, when including all AGN types, can be represented as a single power-law of slope $-0.54 \pm 0.06$. The Eddington ratio of the Seyferts is usually 2-4 decades higher than that of the LINERs, ALGs and HII galaxies, which are mostly detected with Eddington ratios <10$^{-3}$. Using [O III] line measurements and BH masses from the literature, we show that LINERs, HII galaxies and ALGs follow similar correlations to low luminosities, suggesting that some 'inactive' galaxies may harbour AGN.
description: 20 pages + 42 pages of online supplementary material 15 figures, 7 tables (additional 150 figures and 6 tables in online supplementary material) Accepted for publication in MNRAS, 15th November 2021
Quantum Monte Carlo study of a magnetic-field-driven 2D superconductor-insulator transition
Creators: name: Kim, Kwangmoo
name: Stroud, David
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We numerically study the superconductor-insulator phase transition in a model disordered 2D superconductor as a function of applied magnetic field. The calculation involves quantum Monte Carlo calculations of the (2+1)D XY model in the presence of both disorder and magnetic field. The XY coupling is assumed to have the form -J\cos(θ_i-θ_j-A_{ij}), where A_{ij} has a mean of zero and a standard deviation ΔA_{ij}. In a real system, such a model would be approximately realized by a 2D array of small Josephson-coupled grains with slight spatial disorder and a uniform applied magnetic field. The different values ΔA_{ij} then corresponds to an applied field such that the average number of flux quanta per plaquette has various integer values N: larger N corresponds to larger ΔA_{ij}. For any value of ΔA_{ij}, there appears to be a critical coupling constant K_c(ΔA_{ij})=\sqrt{[J/(2U)]_c}, where U is the charging energy, above which the system is a Mott insulator; there is also a corresponding critical conductivity σ^*(ΔA_{ij}) at the transition. For ΔA_{ij}=\infty, the order parameter of the transition is a renormalized coupling constant g. Using a numerical technique appropriate for disordered systems, we show that the transition at this value of ΔA_{ij} takes place from an insulating (I) phase to a Bose glass (BG) phase, and that the dynamical critical exponent characterizing this transition is z \sim 1.3. By contrast, z=1 for this model at ΔA_{ij}=0. We suggest that the superconductor to insulator transition is actually of this I to BG class at all nonzero ΔA_{ij}'s, and we support this interpretation by both numerical evidence and an analytical argument based on the Harris criterion.
description: 17 pages, 23 figures, accepted for publication in Phys. Rev. B
Theoretical prediction of Xe-containing polymer
Creators: name: Zhao, Rui
name: Sheng, Li
name: Gao, Kunqi
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Biophysics
subject: Biochemistry
subject: Physical Sciences not elsewhere classified
subject: Cell Biology
subject: Physiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Immunology
subject: FOS: Clinical medicine
subject: Cancer

description: Density functional theory (DFT) calculation has been performed to investigate the C5N4H10XeH2 molecule and Xe-containing polymer CH2Y(XeY)nCH2 (Y = C4N4H8, n = 1∼6). The topological properties at the bond critical point and the electron localisation function analysis show that the Xe-N bond in C5N4H10XeH2 is covalent. Two dissociation channels have been predicted to investigate the stability of C5N4H10XeH2, in which the products of the two-body dissociation channel are Xe and C5N4H12, and the energy barrier is 5.2 kcal mol−1. We also study the CH2Y(XeY)nCH2 polymer, in which Xe is on the one dimensional extension chain. Besides, two one-dimensional chains joined together by Xe associatione, further form two-dimensional network structures. And two network structures with Xe as the skeleton have been optimised by DFT calculation, each of which contains multiple Xe atoms.
Lifshitz Point in the Phase Diagram of Resonantly Interacting $^6Li$-$^{40}K$ Mixtures
Creators: name: Gubbels, K. B.
name: Baarsma, J. E.
name: Stoof, H. T. C.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We consider a strongly interacting ${}^{6}$Li-${}^{40}$K mixture, which is imbalanced both in the masses and the densities of the two fermionic species. At present, it is the experimentalist's favorite for reaching the superfluid regime. We construct an effective thermodynamic potential that leads to excellent agreement with Monte Carlo results for the normal state. We use it to determine the universal phase diagram of the mixture in the unitarity limit, where we find, in contrast to the mass-balanced case, the presence of a Lifshitz point. This point is characterized by the effective mass of the Cooper pairs becoming negative, which signals an instability towards a supersolid phase.
description: Replaced with published version
Axions and the pulsation periods of variable white dwarfs revisited
Creators: name: Isern, J.
name: García-Berro, E.
name: Althaus, L. G.
name: Córsico, A. H.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Axions are the natural consequence of the introduction of the Peccei-Quinn symmetry to solve the strong CP problem. All the efforts to detect such elusive particles have failed up to now. Nevertheless, it has been recently shown that the luminosity function of white dwarfs is best fitted if axions with a mass of a few meV are included in the evolutionary calculations. Our aim is to show that variable white dwarfs can provide additional and independent evidence about the existence of axions. The evolution of a white dwarf is a slow cooling process that translates into a secular increase of the pulsation periods of some variable white dwarfs, the so-called DAV and DBV types. Since axions can freely escape from such stars, their existence would increase the cooling rate and, consequently, the rate of change of the periods as compared with the standard ones. The present values of the rate of change of the pulsation period of G117-B15A are compatible with the existence of axions with the masses suggested by the luminosity function of white dwarfs, in contrast with previous estimations. Furthermore, it is shown that if such axions indeed exist, the drift of the periods of pulsation of DBV stars would be noticeably perturbed.
description: Accepted for publication in Astronomy & Astrophysics
Auxiliary field method for the square root potential
Creators: name: Silvestre-Brac, Bernard
name: Semay, Claude
name: Buisseret, Fabien
Publisher: name: arXiv
Year: 2009
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Using the auxiliary field method, we give an analytical expression for the eigenenergies of a system composed of two non-relativistic particles interacting via a potential of type $\sqrt{a^2 r^2 + b}$. This situation is usual in the case of hybrid mesons in which the quark-antiquark pair evolves in an excited gluonic field. Asymptotic expressions are proposed and the approximate results are compared to the exact ones. It is shown that the accuracy is excellent.
description: 2 figures
On modeling the scalar meson dynamics with Resonance Chiral Theory
Creators: name: Ivashyn, S.
name: Korchin, A.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The features of the Resonance Chiral Theory (RChT) related to the description of the lightest scalar resonances, sigma, f0(980) and a0(980), are discussed. Major attention is paid to the fits of the invariant mass distributions in the radiative decays of the phi(1020) meson. The study of the scalar sector in RChT is motivated by the success of the theory predictive power in numerous processes with other types of resonances. We conclude that RChT is sufficiently flexible to describe these decays, however the further quantitative improvement is required. The technical work-outs and related important questions are outlined.
description: 7 pages, 1 figure, 1 table. To appear in the proceedings of EFT'09, International Workshop on Effective Field Theories: from the Pion to the Upsilon, 1-6 February 2009, Valencia (Spain)
Compactification of IIB Theory with Fluxes and Axion-Dilaton String Cosmology
Creators: name: Konishi, Eiji
name: Maharana, Jnanadeva
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Compactification of type IIB theory on torus, in the presence of fluxes, is considered. The reduced effective action is expressed in manifestly S-duality invariant form. Cosmological solutions of the model are discussed in several cases in the Pre-Big Bang scenario.
description: 22 pages