cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Galilean symmetry in noncommutative Gravitational Quantum Well
Creators: name: Saha, Anirban
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A thorough analysis of Galilean symmetries for the gravitational well problem on a noncommutative plane is presented. A complete closure of the one-parameter centrally extended Galilean algebra is realised for the model. This implies that the field theoretic model constructed to describe noncommutative gravitational quantum well in \cite{ani} is indeed independent of the coordinate choice. Hence the energy spectrum predicted by the model can be associated with the experimental results to establish the upper-bound on time-space noncommutative parameter. Interestingly, noncommutativity is shown to increase the gravitational pull on the neutron trapped in the gravitational well.
description: 9 pages, Revtex, Section I and IV rewritten, Accepted for publication in Phys. Rev. D
Anisotropic susceptibility of the geometrically frustrated spin-chain compound Ca3Co2O6
Creators: name: Hardy, Vincent
name: Flahaut, Delphine
name: Fresard, Raymond
name: Maignan, Antoine
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Ca3Co2O6 is a system exhibiting a series of fascinating properties, including magnetization plateaus and remarkably slow dynamics at low-T. These properties are intimately related to the geometrical frustration, which results from a particular combination of features: (i) the chains are arranged on a triangular lattice; (ii) there is a large uniaxial anisotropy; (iii) the intrachain and interchain couplings are ferromagnetic and antiferromagnetic, respectively. The uniaxial anisotropy is thus an issue of crucial importance for the analysis of the physical properties of Ca3Co2O6. However, it turns out that no precise investigation of this magnetic anisotropy has been performed so far. On the basis of susceptibility data directly recorded on single crystals, the present study reports on quantitative information about the anisotropy of Ca3Co2O6.
description: 10 pages, 5 figures
2.5a_Duc: Experimental analysis of wind turbine blade loading when applying wind farm control strategies - Preliminary results from SMARTEOLE field tests
Creators: name: Duc, Thomas
name: Tagliatti, Federico
name: Alloin, Lucas
name: Girard, Nicolas
name: Giebel, Gregor
name: Meseguer, Albert
name: Andersen, Søren
name: Tuhfe Göçmen
Publisher: name: Zenodo
Year: 2019

description: Presentation from WESC 2019 in the session 2.5a "Wind farm control". Initial results from a master's thesis realized by Federico Tagliatti and co-supervised by Engie Green and DTU.
Coherent transport of cold atoms in angle-tuned optical lattices
Creators: name: Franzosi, Roberto
name: Cristiani, Matteo
name: Sias, Carlo
name: Arimondo, Ennio
Publisher: name: arXiv
Year: 2006
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Optical lattices with a large spacing between the minima of the optical potential can be created using the angle-tuned geometry where the 1-D periodic potential is generated by two propagating laser beams intersecting at an angle different from $π$. The present work analyzes the coherent transport for the case of this geometry. We show that the potential depth can be kept constant during the transport by choosing a magic value for the laser wavelength. This value agrees with that of the counterpropagating laser case, and the magic wavelength does not depend of the optical lattice geometry. Moreover, we find that this scheme can be used to implement controlled collision experiments under special geometric conditions. Finally we study the transport of hyperfine-Zeeman states of rubidium 87.
description: 8 pages, 5 figures, one section added, in press in Phys. Rev. A
Differential Modelling Systematics across the HR Diagram from Asteroseismic Surface Corrections
Creators: name: Ong, J. M. Joel
name: Basu, Sarbani
name: McKeever, Jean M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Localised modelling error in the near-surface layers of evolutionary stellar models causes the frequencies of their normal modes of oscillation to differ from those of actual stars with matching interior structures. These frequency differences are referred to as the asteroseismic surface term. Global stellar properties estimated via detailed constraints on individual mode frequencies have previously been shown to be robust with respect to different parameterisations of this surface term. It has also been suggested that this may be true of a broader class of nonparametric treatments. We examine systematic differences in inferred stellar properties with respect to different surface-term treatments, both for a statistically large sample of main-sequence stars, as well as for a sample of red giants, for which no such characterisation has previously been done. For main-sequence stars, we demonstrate that while masses and radii, and hence ages, are indeed robust to the choice of surface term, the inferred initial helium abundance $Y_0$ is sensitive to the choice of surface correction. This implies that helium-abundance estimates returned from detailed asteroseismology are methodology-dependent. On the other hand, for our red giant sample, nonparametric surface corrections return dramatically different inferred stellar properties than parametric ones. The nature of these differences suggests that such nonparametric methods should be preferred for evolved stars; this should be verified on a larger sample.
description: 18 pages, 12 figures. Accepted for publication in ApJ
The Stokes-Einstein Relation in Supercooled Aqueous Solutions of Glycerol
Creators: name: Chen, Bo
name: Sigmund, Eric E.
name: Halperin, W. P.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The diffusion of glycerol molecules decreases with decreasing temperature as its viscosity increases in a manner simply described by the Stokes-Einstein(SE) relation. Approaching the glass transition, this relation breaks down as it does with a number of other pure liquid glass formers. We have measured the diffusion coefficient for binary mixtures of glycerol and water and find that the Stokes-Einstein relation is restored with increasing water concentration. Our comparison with theory suggests that addition of water postpones the formation of frustration domains
description: 4 Pages and 3 Figures
J. Chr. Schythe - A Danish Chemist parts 1 and 2, The Greenland and Iceland Voyages.pdf
Creators: name: Wentrup, Curt
Publisher: name: figshare
Year: 2021
Subjects: subject: Geochemistry
subject: FOS: Earth and related environmental sciences
subject: 220206 History and Philosophy of Science (incl. Non-historical Philosophy of Science)
subject: FOS: Philosophy, ethics and religion

description: This paper describes Schythe's exploratory and prospecting travels to Greenland 1838 and to Iceland 1839-40.It will be published in the form of two articles in Dansk Kemi 2021, 102, Nr. 2 and 3. The augmented English version is presented here.Two further articles will follow in Nr. 4 (Schythe, the Agriculture and St. St. Blicher 1842-43) and Nr. 5 (Schythe's second Iceland-journey, the geochemical expedition to Hekla 1846).
Nursing students’ perceptions regarding effective interventions used by nurse educators in assisting students to cope with anxiety during the clinical learning experience
Creators: name: Burnstein, Cheryl Judith
Publisher: name: University of British Columbia
Year: 2009

description: Anxiety during the clinical learning experience is an ongoing challenge for nursing students during their education process. It has been demonstrated that nurse educators are poorly prepared to assist anxious students because of the paucity of research related to effective interventions that reduce student anxiety. The purpose of this study is to explore and describe nursing students' perceptions regarding effective interventions that nurse educators use in helping students cope with anxiety during the clinical learning experience. Lazarus and Folkman's (1984) transactional model of stress and coping was used to guide this study. An ethnographic design, using primarily interviewing for the purpose of data collection, was the research method used to conduct this study. The sample included six full-time nursing students from a diploma nursing program, and were recruited on a volunteer basis. Analysis of the data revealed that a significant amount of student anxiety related to personal feelings of inadequacy and lack of self-confidence, primarily due to their lack of knowledge and experience. Findings revealed that students perceived that they must perform perfectly, and they fear the instructor's presence because of the evaluative component associated with the instructor's role. Effective strategies used by nurse educators in helping students to cope with anxiety were directed primarily at developing a trusting relationship between teacher and student. When students perceived that they could trust instructors, they viewed instructors as more approachable and subsequently felt more comfortable to seek them out for help without fear of evaluation. The implications of the findings for nursing education and nursing research are discussed.
Machine Learning Gravitational Waves from Binary Black Hole Mergers
Creators: name: Schmidt, Stefano
name: Breschi, Matteo
name: Gamba, Rossella
name: Pagano, Giulia
name: Rettegno, Piero
name: Riemenschneider, Gunnar
name: Bernuzzi, Sebastiano
name: Nagar, Alessandro
name: Del Pozzo, Walter
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We apply machine learning methods to build a time-domain model for gravitational waveforms from binary black hole mergers, called mlgw. The dimensionality of the problem is handled by representing the waveform's amplitude and phase using a principal component analysis. We train mlgw on about $\mathcal{O}(10^3)$ TEOBResumS and SEOBNRv4 effective-one-body waveforms with mass ratios $q\in[1,20]$ and aligned dimensionless spins $s\in[-0.80,0.95]$. The resulting models are faithful to the training sets at the ${\sim}10^{-3}$ level (averaged on the parameter space). The speed up for a single waveform generation is a factor 10 to 50 (depending on the binary mass and initial frequency) for TEOBResumS and approximately an order of magnitude more for SEOBNRv4. Furthermore, mlgw provides a closed form expression for the waveform and its gradient with respect to the orbital parameters; such an information might be useful for future improvements in GW data analysis. As demonstration of the capabilities of mlgw to perform a full parameter estimation, we re-analyze the public data from the first GW transient catalog (GWTC-1). We find broadly consistent results with previous analyses at a fraction of the cost, although the analysis with spin aligned waveforms gives systematic larger values of the effective spins with respect to previous analyses with precessing waveforms. Since the generation time does not depend on the length of the signal, our model is particularly suitable for the analysis of the long signals that are expected to be detected by third-generation detectors. Future applications include the analysis of waveform systematics and model selection in parameter estimation.
description: 15 pages, 11 figures, submitted to Phys. Rev. D
On formulas for decoding binary cyclic codes
Creators: name: Augot, Daniel
name: Bardet, Magali
name: Faugère, Jean-Charles
Publisher: name: arXiv
Year: 2007
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: We adress the problem of the algebraic decoding of any cyclic code up to the true minimum distance. For this, we use the classical formulation of the problem, which is to find the error locator polynomial in terms of the syndroms of the received word. This is usually done with the Berlekamp-Massey algorithm in the case of BCH codes and related codes, but for the general case, there is no generic algorithm to decode cyclic codes. Even in the case of the quadratic residue codes, which are good codes with a very strong algebraic structure, there is no available general decoding algorithm. For this particular case of quadratic residue codes, several authors have worked out, by hand, formulas for the coefficients of the locator polynomial in terms of the syndroms, using the Newton identities. This work has to be done for each particular quadratic residue code, and is more and more difficult as the length is growing. Furthermore, it is error-prone. We propose to automate these computations, using elimination theory and Grbner bases. We prove that, by computing appropriate Grbner bases, one automatically recovers formulas for the coefficients of the locator polynomial, in terms of the syndroms.
Verification of bootstrap conditions for amplitudes with quark exchanges in QMRK
Creators: name: Bogdan, A. V.
name: Grabovsky, A. V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The compatibility of the multi--Regge form of QCD amplitudes in the quasi--multi--Regge kinematics (QMRK) and the s--channel unitarity imposes some constraints on the effective jet--production vertices. We demonstrate that these constraints known as bootstrap conditions are satisfied for the amplitudes with the Reggeized quark exchanges.
description: 25 pages, 1 figure, uses elsart.cls
Fabrication of $^{15}\textrm{NV}^{-}$ centers in diamond using a deterministic single ion implanter
Creators: name: Groot-Berning, K.
name: Jacob, G.
name: Osterkamp, C.
name: Jelezko, F.
name: Schmidt-Kaler, F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Nitrogen Vacancy (NV) centers in diamond are a platform for several important quantum technologies, including sensing, communication and elementary quantum processors. In this letter we demonstrate the creation of NV centers by implantation using a deterministic single ion source. For this we sympathetically laser-cool single $^{15}\textrm{N}_2^+$ molecular ions in a Paul trap and extract them at an energy of 5.9\,keV. Subsequently the ions are focused with a lateral resolution of 121(35)\,nm and are implanted into a diamond substrate without any spatial filtering by apertures or masks. After high-temperature annealing, we detect the NV centers in a confocal microscope and determine a conversion efficiency of about 0.6\,$\%$. The $^{15}\textrm{NV}$ centers are characterized by optically detected magnetic resonance (ODMR) on the hyperfine transition and coherence time.
description: 13 pages, 7 figures
blocks_3d: Software for general 3d conformal blocks
Creators: name: Erramilli, Rajeev S.
name: Iliesiu, Luca V.
name: Kravchuk, Petr
name: Landry, Walter
name: Poland, David
name: Simmons-Duffin, David
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We introduce the software blocks_3d for computing four-point conformal blocks of operators with arbitrary Lorentz representations in 3d CFTs. It uses Zamolodchikov-like recursion relations to numerically compute derivatives of blocks around a crossing-symmetric configuration. It is implemented as a heavily optimized, multithreaded, C++ application. We give performance benchmarks for correlators containing scalars, fermions, and stress tensors. As an example application, we recompute bootstrap bounds on four-point functions of fermions and study whether a previously observed sharp jump can be explained using the "fake primary" effect. We conclude that the fake primary effect cannot fully explain the jump and the possible existence of a "dead-end" CFT near the jump merits further study.
description: 33 pages + appendices
Commutators of contactomorphisms
Creators: name: Rybicki, Tomasz
Publisher: name: arXiv
Year: 2008
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 22E65, 57R50, 53D10

description: The group of volume preserving diffeomorphisms, the group of symplectomorphisms and the group of contactomorphisms constitute the classical groups of diffeomorphisms. The first homology groups of the compactly supported identity components of the first two groups have been computed by Thurston and Banyaga, respectively. In this paper we solve the long standing problem on the algebraic structure of the third classical diffeomorphism group, i.e. the contactomorphism group. Namely we show that the compactly supported identity component of the group of contactomorphisms is perfect and simple (if the underlying manifold is connected). The result could be applied in various ways.
description: revised version; 38 pages
Arp 116: Interacting System or Chance Alignment?
Creators: name: de Grijs, Richard
name: Robertson, Alasdair R. I.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Using high spatial resolution Hubble Space Telescope/Advanced Camera for Surveys archival imaging observations of Arp 116, centred on the elliptical galaxy NGC 4649, we explore the novel technique of pixel-by-pixel analysis of the galaxy's colour-magnitude diagramme to search for any evidence of recent enhanced star formation due to the apparent tidal interaction with its spiral companion, NGC 4647. From a detailed analysis of the system's geometry, and based on additional circumstantial evidence from extant multi-wavelength observations, we conclude that, while there may be grounds for the tidal-interaction assumption for this system, any interaction has thus far been of insufficient strength to trigger an enhanced level of recent star formation in the elliptical component, although close inspection of our colour images shows a faint excess of bluer pixels (a ~0.20 mag bluer "loop") in the elliptical galaxy on the side of the spiral companion. Given that there appears to be a moderate reservoir of available gas for ongoing star formation (although at low column density), this suggests that we are currently witnessing the onset of the tidal interaction between NGC 4647 and NGC 4649. In addition, the triggering of new star formation in NGC 4649 may be significantly impeded due to the much lower mass of the spiral component.
description: A&A, in press; 7 pages, including one postscript figure at reduced resolution
Causal effects of Circulating Lipid Traits on Epithelial Ovarian Cancer: A Two-sample Mendelian Randomization Study - Supplementary material.
Creators: name: Meng, Hongen
name: Jiang, Li
name: Wang, Rong
name: Alex, John
name: Wang, Fudi
Publisher: name: figshare
Year: 2021
Subjects: subject: 111203 Cancer Genetics
subject: FOS: Clinical medicine
subject: Diseases
subject: 110104 Medical Biochemistry: Lipids
subject: 110709 Tumour Immunology

description: Based on the Mendelian randomization (MR) approach, we evaluated the genetic causal effect of circulating apolipoproteins and lipoprotein lipids, including (Apolipoprotein A1 (APOA1), Apolipoprotein B (APOB), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), and triglycerides (TG)), on EOC progression.
Adapted SES Framework for AEFS and Guidelines for Assessing Sustainability of Agricultural Systems in Europe
Creators: name: Guisepelli, Emmanuel
name: Fleury, Philippe
name: Vincent, Audrey
name: Aalders, Inge
name: Prazan, Jaroslav
name: Vanni, Francesco
Publisher: name: Zenodo
Year: 2018

description: This report, Deliverable D2.1, explains the adapted SES framework for the sustainability assessment of agro-ecological farming systems and operationalises the framework by providing guidance for the analytical work packages (WP3, WP4, WP5, and WP6) and their collection of information and assessment of SES variables.
Decay of baryon inhomogeneities in an expanding universe
Creators: name: Das, Pratik K.
name: Sau, Sovan
name: Saha, Abhisek
name: Sanyal, Soma
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Baryon inhomogeneities can be generated very early in the universe. These inhomogeneities then decay by particle diffusion in an expanding universe. We study the decay of these baryon inhomogeneities in the early universe using the diffusion equation in the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric. We have studied the decay starting from the electroweak phase transition. We calculate the interaction cross section of the quarks with the neutrinos, the electrons and the muons and obtain the diffusion coefficients. The diffusion coefficients are temperature dependent. We find that the expansion of the universe causes the inhomogeneities to decay at a faster rate. We find that the baryon inhomogeneities generated at the electroweak epoch have very low amplitudes at the time of the quark hadron phase transition. So unless inhomogeneities are generated with a very high amplitude (greater than $10^5$ times the background density), they will have no effect on the quark hadron phase transition. After the quark hadron phase transition, we include the interaction of the muons with the neutrons and the protons till 100 MeV. We also find that large density inhomogeneities generated during the quark hadron transition with sizes of the order of 1 km must have amplitudes greater than $10^5 $ times the background density to survive upto the nucleosynthesis epoch in an expanding universe.
description: 20 pages and 7 figures
Accelerating random walks by disorder
Creators: name: Belik, Vitaly
name: Brockmann, Dirk
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate the dynamic impact of heterogeneous environments on superdiffusive random walks known as Lévy flights. We devote particular attention to the relative weight of source and target locations on the rates for spatial displacements of the random walk. Unlike ordinary random walks which are slowed down for all values of the relative weight of source and target, non-local superdiffusive processes show distinct regimes of attenuation and acceleration for increased source and target weight, respectively. Consequently, spatial inhomogeneities can facilitate the spread of superdiffusive processes, in contrast to common belief that external disorder generally slows down stochastic processes. Our results are based on a novel type of fractional Fokker-Planck equation which we investigate numerically and by perturbation theory for weak disorder.
description: 8 pages, 5 figures
Finding low-weight polynomial multiples using discrete logarithm
Creators: name: Didier, Frédéric
name: Laigle-Chapuy, Yann
Publisher: name: arXiv
Year: 2007
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: Finding low-weight multiples of a binary polynomial is a difficult problem arising in the context of stream ciphers cryptanalysis. The classical algorithm to solve this problem is based on a time memory trade-off. We will present an improvement to this approach using discrete logarithm rather than a direct representation of the involved polynomials. This gives an algorithm which improves the theoretical complexity, and is also very flexible in practice.
If sex is your work-- : Reflections on collaborative research in Thailand
Creators: name: Demusz, Kerry Lee
Publisher: name: University of British Columbia
Year: 2009

description: This thesis is a discussion of collaborative research methodologies devised for undertaking research within an organizational context with sex workers in Thailand's northern city of Chiangmai. It is a discussion of how the strategies were derived, the context they were derived for and how they played themselves out, "on the ground." It provides an overview of the literature on the commercial sex industry in Thailand and a more detailed account of the current situation in Chiangmai. It also provides details about how the collaborative partner in this research, a Thai non-governmental organization called EMPOWER, seeks to work within this context. The main discussion in the thesis revolves around how the issues of voice, consent and power melded together to act as a brake on the research process. It also highlights the importance of these issues in terms of undertaking research with women in this setting. Within this context, considerations for collaborative research projects with sex workers are outlined, the tensions between research and activism and elicited and how the issues of consent, voice and power played themselves out on the ground, is discussed. Rather than simply criticizing the process of speaking about "others" and working collaboratively, suggestions for possible future projects are offered as a base from which to move forward. ii It is my hope that this document will add to the expanding literature on women's experience of doing research in the field and their considerations in doing research on not only an academic level but also on an emotive level, in order that the research process can be better understood as well as more considerate of it's "subjects."
The Information Catastrophe
Creators: name: Vopson, Melvin M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Popular Physics (physics.pop-ph)
subject: FOS: Physical sciences
subject: H.3.2
subject: N/A

description: Currently we produce 10 to power 21 digital bits of information annually on Earth. Assuming 20 percent annual growth rate, we estimate that 350 years from now, the number of bits produced will exceed the number of all atoms on Earth, or 10 to power 50. After 250 years, the power required to sustain this digital production will exceed 18.5 TW, or the total planetary power consumption today, and 500 years from now the digital content will account for more than half of the Earths mass, according to the mass energy information equivalence principle. Besides the existing global challenges such as climate, environment, population, food, health, energy and security, our estimates here point to another singularity event for our planet, called the Information Catastrophe.
description: 4 pages
Using acoustic waves to induce high-frequency current oscillations in superlattices
Creators: name: Greenaway, M. T.
name: Balanov, A. G.
name: Fowler, D.
name: Kent, A. J.
name: Fromhold, T. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show that GHz acoustic waves in semiconductor superlattices can induce THz electron dynamics that depend critically on the wave amplitude. Below a threshold amplitude, the acoustic wave drags electrons through the superlattice with a peak drift velocity overshooting that produced by a static electric field. In this regime, single electrons perform drifting orbits with THz frequency components. When the wave amplitude exceeds the critical threshold, an abrupt onset of Bloch-like oscillations causes negative differential velocity. The acoustic wave also affects the collective behavior of the electrons by causing the formation of localised electron accumulation and depletion regions, which propagate through the superlattice, thereby producing self-sustained current oscillations even for very small wave amplitudes. We show that the underlying single-electron dynamics, in particular the transition between the acoustic wave dragging and Bloch oscillation regimes, strongly influence the spatial distribution of the electrons and the form of the current oscillations. In particular, the amplitude of the current oscillations depends non-monotonically on the strength of the acoustic wave, reflecting the variation of the single-electron drift velocity.
description: 10 pages, 8 figures
Coincident onset of charge order and pseudogap in a homogeneous high-temperature superconductor
Creators: name: Betto, D.
name: Nakata, S.
name: Pisani, F.
name: Liu, Y.
name: Hameed, S.
name: Knauft, M.
name: Lin, C.
name: Sant, R.
name: Kummer, K.
name: Yakhou, F.
name: Brookes, N. B.
name: Keimer, B.
name: Minola, M.
Publisher: name: arXiv
Year: 2025
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Understanding high-temperature superconductivity in cuprates requires knowledge of the metallic phase it evolves from, particularly the pseudogap profoundly affecting the electronic properties at low carrier densities. A key question is the influence of chemical disorder, which is ubiquitous but exceedingly difficult to model. Using resonant x-ray scattering, we identified two-dimensional charge order in stoichiometric YBa$_2$Cu$_4$O$_8$ ($T_c$ = 80 K), which is nearly free of chemical disorder. The charge order amplitude shows a concave temperature dependence and vanishes sharply at $T^*$ = 200 K, the onset of a prominent pseudogap previously determined by spectroscopy, suggesting a causal link between these phenomena. The gradual onset of charge order in other cuprates is thus likely attributable to an inhomogeneous distribution of charge ordering temperatures due to disorder induced by chemical substitution. The relationship between the pseudogap and the disorder-induced gradual freeze-out of charge carriers remains a central issue in research on high-$T_c$ superconductors.
description: D. Betto and S. Nakata contributed equally. (21 pages, 12 figures)
First results from a Dark Matter search with liquid Argon at 87 K in the Gran Sasso Underground Laboratory
Creators: name: Benetti, P.
name: Acciarri, R.
name: Adamo, F.
name: Baibussinov, B.
name: Baldo-Ceolin, M.
name: Belluco, M.
name: Calaprice, F.
name: Calligarich, E.
name: Cambiaghi, M.
name: Carbonara, F.
name: Cavanna, F.
name: Centro, S.
name: Cocco, A. G.
name: Di Pompeo, F.
name: Ferrari, N.
name: Fiorillo, G.
name: Galbiati, C.
name: Gallo, V.
name: Grandi, L.
name: Ianni, A.
name: Mangano, G.
name: Meng, G.
name: Montanari, C.
name: Palamara, O.
name: Pandola, L.
name: Pietropaolo, F.
name: Raselli, G. L.
name: Rossella, M.
name: Rubbia, C.
name: Szelc, A. M.
name: Ventura, S.
name: Vignoli, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A new method of searching for dark matter in the form of weakly interacting massive particles (WIMP) has been developed with the direct detection of the low energy nuclear recoils observed in a massive target (ultimately many tons) of ultra pure Liquid Argon at 87 K. A high selectivity for Argon recoils is achieved by the simultaneous observation of both the VUV scintillation luminescence and of the electron signal surviving columnar recombination, extracted through the liquid-gas boundary by an electric field. First physics results from this method are reported, based on a small 2.3 litre test chamber filled with natural Argon and an accumulated fiducial exposure of about 100 kg x day, supporting the future validity of this method with isotopically purified 40Ar and for a much larger unit presently under construction with correspondingly increased sensitivities.
description: 26 pages, 8 figures, submitted to astroparticle physics
Accelerating Number Theoretic Transformations for Bootstrappable Homomorphic Encryption on GPUs
Creators: name: Kim, Sangpyo
name: Jung, Wonkyung
name: Park, Jaiyoung
name: Ahn, Jung Ho
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cryptography and Security (cs.CR)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Homomorphic encryption (HE) draws huge attention as it provides a way of privacy-preserving computations on encrypted messages. Number Theoretic Transform (NTT), a specialized form of Discrete Fourier Transform (DFT) in the finite field of integers, is the key algorithm that enables fast computation on encrypted ciphertexts in HE. Prior works have accelerated NTT and its inverse transformation on a popular parallel processing platform, GPU, by leveraging DFT optimization techniques. However, these GPU-based studies lack a comprehensive analysis of the primary differences between NTT and DFT or only consider small HE parameters that have tight constraints in the number of arithmetic operations that can be performed without decryption. In this paper, we analyze the algorithmic characteristics of NTT and DFT and assess the performance of NTT when we apply the optimizations that are commonly applicable to both DFT and NTT on modern GPUs. From the analysis, we identify that NTT suffers from severe main-memory bandwidth bottleneck on large HE parameter sets. To tackle the main-memory bandwidth issue, we propose a novel NTT-specific on-the-fly root generation scheme dubbed on-the-fly twiddling (OT). Compared to the baseline radix-2 NTT implementation, after applying all the optimizations, including OT, we achieve 4.2x speedup on a modern GPU.
description: 12 pages, 13 figures, to appear in IISWC 2020
On the ground state energy of a gas of interacting polarons in a magnetic field
Creators: name: Putteneers, K.
name: Brosens, F.
name: Klimin, S. N.
name: Devreese, J. T.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The ground-state energy of a three-dimensional polaron gas in a magnetic field is investigated. An upper bound for the ground-state energy is derived within a variational approach which is based on a many-body generalization of the Lee-Low-Pines transformation. The basic contributing ingredients found are the ground-state energy and the static structure factor of the homogeneous electron gas in a magnetic field. Both these quantities are derived in the Hartree-Fock approximation. The resulting ground-state energy of the polaron gas is analyzed as a function of the electron density and of the magnetic field strength.
description: 10 pages, 3 figures
Spectroscopy of 9C via resonance scattering of protons on 8B
Creators: name: Rogachev, G. V.
name: Kolata, J. J.
name: Volya, A. S.
name: Becchetti, F. D.
name: Chen, Y.
name: DeYoung, P. A.
name: Lupton, J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The structure of the neutron-deficient 9C isotope was studied via elastic scattering of radioactive 8B on protons. An excitation function for resonance elastic scattering was measured in the energy range from 0.5 to 3.2 MeV in the center-of-momentum system. A new excited state in 9C was observed at an excitation energy of 3.6 MeV. An R-matrix analysis indicates spin-parity 5/2- for the new state. The results of this experiment are compared with Continuum Shell Model calculations.
description: 9 pages, 8 figures, 3 tables
title: Population-based cancer survival in Kuwait
Creators: name: Alawadhi, E
Publisher: name: London School of Hygiene & Tropical Medicine
Year: 2021

description: Population-based cancer survival is a key measure of the effectiveness of health systems in managing cancer. Monitoring survival over time and between countries is also crucial to assess inequalities and drive policies for cancer control. In this thesis, I use data from the Kuwait Cancer Registry (KCR) to produce a comprehensive profile of population-based cancer survival in Kuwait, to enable evaluation of cancer care in the country. In order to produce robust population-based net survival estimates, it is necessary to have the full date of both the cancer diagnosis and the last known vital status for all patients. All deaths must be included, irrespective of the cause of death. A new approach to obtain followup data on the vital status of all registered Kuwaiti cancer patients was implemented. This enabled the estimation of population-based cancer survival in Kuwait for the first time, using robust and unbiased methods that allow comparisons to be made over time and between different populations. Further analyses of survival by stage at diagnosis were also performed, to provide a deeper understanding of cancer survival in Kuwait. Finally, an overall assessment of progress against cancer was performed, using the three main cancer control metrics: incidence, survival and mortality. The findings demonstrate that survival has improved for many cancers in Kuwait during 2000-2013. However, further research is required to help dissect the underlying causes of the differences in survival between Kuwait and other countries with comparable income and health systems. It also highlighted the importance of more complete collection of stage data, the necessity of improving early detection, and the need for systematic production and assessment of cancer control measures in Kuwait. The findings should assist policymakers and practitioners investing in the Kuwaiti healthcare system to achieve optimal outcomes and provide guidance towards future research in the country.
Comment on ``A quantum-classical bracket that satisfies the Jacobi identity'' [J. Chem. Phys. 124, 201104 (2006)]
Creators: name: Salcedo, L. L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: It shown that the quantum-classical dynamical bracket recently proposed in J. Chem. Phys. 124, 201104 (2006) fails to satisfy the Jacobi identity.
description: 2 pages, no figures
Electronic structure and optical properties of quantum crystals from first principles calculations in the Born-Oppenheimer approximation
Creators: name: Gorelov, Vitaly
name: Ceperley, David M.
name: Holzmann, Markus
name: Pierleoni, Carlo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We develop a formalism to accurately account for the renormalization of electronic structure due to quantum and thermal nuclear motions within the Born-Oppenheimer approximation. We focus on the fundamental energy gap obtained from electronic addition and removal energies from Quantum Monte Carlo calculations in either the canonical or grand canonical ensembles. The formalism applies as well to effective single electron theories such as those based on Density Functional Theory. We show that electronic (Bloch) crystal momentum can be restored by marginalizing the total electron-ion wave function with respect to the nuclear equilibrium distribution, and we describe an explicit procedure to establish the band structure of electronic excitations for quantum crystals within the Born-Oppenheimer approximation. Based on the Kubo-Greenwood equation, we discuss the effects of nuclear motion on optical conductivity. Our methodology applies to the low temperature regime where nuclear motion is quantized and in general differs from the semi-classical approximation. We apply our method to study the electronic structure of C2/c-24 crystalline hydrogen at 200K and 250 GPa and discuss the optical absorption profile of hydrogen crystal at 200K and carbon diamond at 297K.
Ill-Behaved Convergence of a Model of the Gd3Ga5O12 Garnet Antiferromagnet with Truncated Magnetic Dipole-Dipole Interactions
Creators: name: Yavors'kii, Taras
name: Gingras, Michel J. P.
name: Enjalran, Matthew
Publisher: name: arXiv
Year: 2006
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Previous studies have found that calculations which consider long-range magnetic dipolar interactions truncated at a finite cut-off distance Rc predict spurious (unphysical) long-range ordered phases for Ising and Heisenberg systems on the pyrochlore lattice. In this paper we show that, similar to these two cases, calculations that use truncated dipolar interactions to model the Gd3Ga5O12 garnet antiferromagnet also predict unphysical phases with incommensurate ordering wave vector q_ord that is very sensitive to the dipolar cut-off distance Rc.
description: 7 pages, 2 color figures; Proceedings of the HFM2006 conference, to appear in a special issue of J. Phys.: Condens. Matter
Dispersion total photoproduction sum rules for nucleons and few-body nuclei revisited
Creators: name: Gerasimov, S. B.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The questions on the presense and quantitative role of the constant terms in the real part of the high-energy photon-nucleon and photon-nucleus amplitudes representing the contribution of the non-Regge (the fixed j=0-pole) singularities in the finite-energy sum rules (FESR) for the photoabsorption cross sections on nucleons and the lightest atomic nuclei are discussed and new testable relations are presented for relevant combinations of the Compton scattering amplitudes.
description: 8 pages, Latex; The report presented at Advanced Studies Institute: Symmetries and Spin (SPIN-Praha-2006), Prague, Czech Republic, 19-26 Jul 2006
Automated Artefact Relevancy Determination from Artefact Metadata and Associated Timeline Events
Creators: name: Du, Xiaoyu
name: Le, Quan
name: Scanlon, Mark
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cryptography and Security (cs.CR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Case-hindering, multi-year digital forensic evidence backlogs have become commonplace in law enforcement agencies throughout the world. This is due to an ever-growing number of cases requiring digital forensic investigation coupled with the growing volume of data to be processed per case. Leveraging previously processed digital forensic cases and their component artefact relevancy classifications can facilitate an opportunity for training automated artificial intelligence based evidence processing systems. These can significantly aid investigators in the discovery and prioritisation of evidence. This paper presents one approach for file artefact relevancy determination building on the growing trend towards a centralised, Digital Forensics as a Service (DFaaS) paradigm. This approach enables the use of previously encountered pertinent files to classify newly discovered files in an investigation. Trained models can aid in the detection of these files during the acquisition stage, i.e., during their upload to a DFaaS system. The technique generates a relevancy score for file similarity using each artefact's filesystem metadata and associated timeline events. The approach presented is validated against three experimental usage scenarios.
Immigration Document Classification and Automated Response Generation
Creators: name: Mukherjee, Sourav
name: Oates, Tim
name: DiMascio, Vince
name: Jean, Huguens
name: Ares, Rob
name: Widmark, David
name: Harder, Jaclyn
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: In this paper, we consider the problem of organizing supporting documents vital to U.S. work visa petitions, as well as responding to Requests For Evidence (RFE) issued by the U.S.~Citizenship and Immigration Services (USCIS). Typically, both processes require a significant amount of repetitive manual effort. To reduce the burden of mechanical work, we apply machine learning methods to automate these processes, with humans in the loop to review and edit output for submission. In particular, we use an ensemble of image and text classifiers to categorize supporting documents. We also use a text classifier to automatically identify the types of evidence being requested in an RFE, and used the identified types in conjunction with response templates and extracted fields to assemble draft responses. Empirical results suggest that our approach achieves considerable accuracy while significantly reducing processing time.
description: To appear in ICDM 2020 workshop: MLLD-2020
Quasi-equilibrium models of high-redshift disc galaxy evolution
Creators: name: Furlanetto, Steven R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In recent years, simple models of galaxy formation have been shown to provide reasonably good matches to available data on high-redshift luminosity functions. However, these prescriptions are primarily phenomenological, with only crude connections to the physics of galaxy evolution. Here we introduce a set of galaxy models that are based on a simple physical framework but incorporate more sophisticated models of feedback, star formation, and other processes. We apply these models to the high-redshift regime, showing that most of the generic predictions of the simplest models remain valid. In particular, the stellar mass--halo mass relation depends almost entirely on the physics of feedback (and is thus independent of the details of small-scale star formation) and the specific star formation rate is a simple multiple of the cosmological accretion rate. We also show that, in contrast, the galaxy's gas mass is sensitive to the physics of star formation, although the inclusion of feedback-driven star formation laws significantly changes the naive expectations. While these models are far from detailed enough to describe every aspect of galaxy formation, they inform our understanding of galaxy formation by illustrating several generic aspects of that process, and they provide a physically-grounded basis for extrapolating predictions to faint galaxies and high redshifts currently out of reach of observations. If observations show violations from these simple trends, they would indicate new physics occurring inside the earliest generations of galaxies.
description: 20 pages, 13 figures, in press at MNRAS
Hubble Space Telescope Observations of SV Cam: II. First Derivative Lightcurve Modelling using PHOENIX and ATLAS Model Atmospheres
Creators: name: Jeffers, S. V.
name: Aufdenberg, J. P.
name: Hussain, G. A. J.
name: Cameron, A. Collier
name: Holzwarth, V. R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The variation of the specific intensity across the stellar disc is essential input parameter in surface brightness reconstruction techniques such as Doppler imaging, where the relative intensity contributions of different surface elements are important in detecting starspots. We use PHOENIX and ATLAS model atmospheres to model lightcurves derived from high precision (S/N ~ 5000) HST data of the eclipsing binary SV Cam (F9V + K4V), where the variation of specific intensity across the stellar disc will determine the contact points of the binary system lightcurve. For the first time we use chi^2 comparison fits to the first derivative profiles to determine the best-fitting model atmosphere. We show the wavelength dependence of the limb darkening and that the first derivative profile is sensitive to the limb-darkening profile very close to the limb of the primary star. It is concluded that there is only a marginal difference (< 1sigma) between the chi^2 comparison fits of the two model atmospheres to the HST lightcurve at all wavelengths. The usefulness of the second derivative of the light-curve for measuring the sharpness of the primary's limb is investigated, but we find that the data are too noisy to permit a quantitative analysis.
description: 10 pages, 20 figures, accepted by MNRAS