cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Hubble expansion and structure formation in the "running FLRW model" of the cosmic evolution
Creators: name: Grande, Javier
name: Sola, Joan
name: Basilakos, Spyros
name: Plionis, Manolis
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A new class of FLRW cosmological models with time-evolving fundamental parameters should emerge naturally from a description of the expansion of the universe based on the first principles of quantum field theory and string theory. Within this general paradigm, one expects that both the gravitational Newton's coupling, G, and the cosmological term, Lambda, should not be strictly constant but appear rather as smooth functions of the Hubble rate. This scenario ("running FLRW model") predicts, in a natural way, the existence of dynamical dark energy without invoking the participation of extraneous scalar fields. In this paper, we perform a detailed study of these models in the light of the latest cosmological data, which serves to illustrate the phenomenological viability of the new dark energy paradigm as a serious alternative to the traditional scalar field approaches. By performing a joint likelihood analysis of the recent SNIa data, the CMB shift parameter, and the BAOs traced by the Sloan Digital Sky Survey, we put tight constraints on the main cosmological parameters. Furthermore, we derive the theoretically predicted dark-matter halo mass function and the corresponding redshift distribution of cluster-size halos for the "running" models studied. Despite the fact that these models closely reproduce the standard LCDM Hubble expansion, their normalization of the perturbation's power-spectrum varies, imposing, in many cases, a significantly different cluster-size halo redshift distribution. This fact indicates that it should be relatively easy to distinguish between the "running" models and the LCDM cosmology using realistic future X-ray and Sunyaev-Zeldovich cluster surveys.
description: Version published in JCAP 08 (2011) 007: 1+41 pages, 6 Figures, 1 Table. Typos corrected. Extended discussion on the computation of the linearly extrapolated density threshold above which structures collapse in time-varying vacuum models. One appendix, a few references and one figure added
A macro-realism inequality for opto-electro-mechanical systems
Creators: name: Lambert, Neill
name: Johansson, Robert
name: Nori, Franco
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show how to apply the Leggett-Garg inequality to opto-electro-mechanical systems near their quantum ground state. We find that by using a dichotomic quantum non-demolition measurement (via, e.g., an additional circuit-QED measurement device) either on the cavity or on the nanomechanical system itself, the Leggett-Garg inequality is violated. We argue that only measurements on the mechanical system itself give a truly unambigous violation of the Leggett-Garg inequality for the mechanical system. In this case, a violation of the Leggett-Garg inequality indicates physics beyond that of "macroscopic realism" is occurring in the mechanical system. Finally, we discuss the difficulties in using unbound non-dichotomic observables with the Leggett-Garg inequality.
description: 9 pages, 2 figures. Added additional figure (2b), and associated content
Abordagens Em Empreendedorismo E Biotecnologia: Relato De Experiência Nanogreen
Creators: name: Da Cruz, Nayara Soares
name: Da Silva, Pedro Patrique Ferreira
name: Orlandi, Ana Carolina de Andrade Lima
name: CARMO, Talita Souza
Publisher: name: figshare
Year: 2021
Subjects: Biotechnology

description: Abordagens Em Empreendedorismo E Biotecnologia: Relato De Experiência Nanogreen
O Papel Da Extensão Universitária na Redução das Desigualdades: Uma Abordagem Pedagógica No Ensino De Ciências Em Escolas Públicas Do DF
Creators: name: Brandalise, Eduardo Franco
Publisher: name: figshare
Year: 2021
Subjects: Biotechnology

description: O Papel Da Extensão Universitária na Redução das Desigualdades: Uma Abordagem Pedagógica No Ensino De Ciências Em Escolas Públicas Do DF
Shear channel correlators from hot charged black holes
Creators: name: Brattan, Daniel K.
name: Gentle, Simon A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We compute numerically the full retarded Green's functions for conserved currents in the shear channel of a (2+1)-dimensional field theory at non-zero temperature and density. This theory is assumed to be holographically dual to a non-extremal, electric Reissner-Nordstr\om AdS4 black hole with planar horizon. Using the holographic description we obtain results for arbitrary frequencies and momenta and survey the detailed structure of these correlators. In particular, we demonstrate the `repulsion' and `clover-leaf crossing' of their poles and stress the importance of the residues at the poles beyond the hydrodynamic regime. As a consistency check, we show that our results agree precisely with existing literature for the appropriate quasinormal frequencies of the bulk theory.
description: 16 pages, 8 figures. Animations available from http://www.maths.dur.ac.uk/~rcqn58/research.html . v2: references added. v3: published version, appendices added
Bactérias simbiontes de artrópodes terrestres como fonte de compostos antimicrobianos
Creators: name: Réus, Maurício Magagnin
name: Nandi, Ana Julia Ricardo
name: Vieira, Michelly Maciel Longo
name: Feliciano, Luiz Felipe de Albuquerque
name: Rigon Zimmer, Karine
name: Seixas, Adriana
name: Fraga, Fernando Bueno Ferreira Fonseca de
Publisher: name: figshare
Year: 2021
Subjects: Biotechnology

description: Bactérias simbiontes de artrópodes terrestres como fonte de compostos antimicrobianos
Phase transitions in the distribution of the Andreev conductance of superconductor-metal junctions with multiple transverse modes
Creators: name: Damle, Kedar
name: Majumdar, Satya N.
name: Tripathi, Vikram
name: Vivo, Pierpaolo
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We compute analytically the full distribution of Andreev conductance $G_{\mathrm{NS}}$ of a metal-superconductor interface with a large number $N_c$ of transverse modes, using a random matrix approach. The probability distribution $\mathcal{P}(G_{\mathrm{NS}},N_c)$ in the limit of large $N_c$ displays a Gaussian behavior near the average value $= (2-\sqrt{2}) N_c$ and asymmetric power-law tails in the two limits of very small and very large $G_{\mathrm{NS}}$. In addition, we find a novel third regime sandwiched between the central Gaussian peak and the power law tail for large $G_{\mathrm{NS}}$. Weakly non-analytic points separate these four regimes---these are shown to be consequences of three phase transitions in an associated Coulomb gas problem.
description: 4 pages, 1 fig. Minor changes. Published version
Quantum Geons and Noncommutative Spacetimes
Creators: name: Balachandran, A. P.
name: Ibort, A.
name: Marmo, G.
name: Martone, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Physical considerations strongly indicate that spacetime at Planck scales is noncommutative. A popular model for such a spacetime is the Moyal plane. The Poincarè group algebra acts on it with a Drinfel'd-twisted coproduct. But the latter is not appropriate for more complicated spacetimes such as those containing the Friedman-Sorkin (topological) geons. They have rich diffeomorphism groups and in particular mapping class groups, so that the statistics groups for N identical geons is strikingly different from the permutation group $S_N$. We generalise the Drinfel'd twist to (essentially) generic groups including to finite and discrete ones and use it to modify the commutative spacetime algebras of geons as well to noncommutative algebras. The latter support twisted actions of diffeos of geon spacetimes and associated twisted statistics. The notion of covariant fields for geons is formulated and their twisted versions are constructed from their untwisted versions. Non-associative spacetime algebras arise naturally in our analysis. Physical consequences, such as the violation of Pauli principle, seem to be the outcomes of such nonassociativity. The richness of the statistics groups of identical geons comes from the nontrivial fundamental groups of their spatial slices. As discussed long ago, extended objects like rings and D-branes also have similar rich fundamental groups. This work is recalled and its relevance to the present quantum geon context is pointed out.
description: 41 pages
On quasi-local charges and Newman--Penrose type quantities in Yang--Mills theories
Creators: name: Farkas, Réka
name: Szabados, László B
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We generalize the notion of quasi-local charges, introduced by P. Tod for Yang--Mills fields with unitary groups, to non-Abelian gauge theories with arbitrary gauge group, and calculate its small sphere and large sphere limits both at spatial and null infinity. We show that for semisimple gauge groups no reasonable definition yield conserved total charges and Newman--Penrose (NP) type quantities at null infinity in generic, radiative configurations. The conditions of their conservation, both in terms of the field configurations and the structure of the gauge group, are clarified. We also calculate the NP quantities for stationary, asymptotic solutions of the field equations with vanishing magnetic charges, and illustrate these by explicit solutions with various gauge groups.
description: 22 pages, typos corrected, appearing in Classical and Quantum Gravity
Collider signatures of the SO(5) x U(1) gauge-Higgs unification
Creators: name: Hosotani, Yutaka
name: Tanaka, Minoru
name: Uekusa, Nobuhiro
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Collider signatures of the $SO(5) \times U(1)$ gauge-Higgs unification model in the Randall-Sundrum warped space are explored. Gauge couplings of quarks and leptons receive small corrections from the fifth dimension whose effects are tested by the precision data. It is found that the forward-backward asymmetries in $e^+e^-$ collisions on the $Z$ pole are well explained in a wide range of the warp factor $z_L$, but the model is consistent with the branching fractions of $Z$ decay only for large $z_L \simg 10^{15}$. Kaluza-Klein (KK) spectra of gauge bosons, quarks, and leptons as well as gauge and Higgs couplings of low-lying KK excited states are determined. Right-handed quarks and leptons have larger couplings to the KK gauge bosons than left-handed ones. Production rates of Higgs bosons and KK states at Tevatron, LHC and ILC are evaluated. The first KK $Z$ has a mass 1130 GeV with a width 422 GeV for $z_L = 10^{15}$. The current limit on the $Z'$ production at Tevatron and LHC indicates $z_L >10^{15}$. A large effect of parity violation appears in the difference between the rapidity distributions of $e^+$ and $e^-$ in the decay of the first KK $Z$. The first KK gauge bosons decay into light and heavy quarks evenly.
description: 45 pages, 6 figures. Contributions from the first KK photon are taken into account
Effects of adhesive z-connections on the properties of a model wood composite
Creators: name: He, Wenchang
Publisher: name: University of British Columbia
Year: 2017

description: Adhesive is a costly and critical component of wood composites. The relationship between adhesive distribution and properties of wood composites has been explored, but few studies have attempted to alter the distribution of adhesive in wood composites as a way of improving their properties. In this thesis, I hypothesize that creating a 3-dimensionally inter-connected adhesive network by introducing adhesive Z-connections will improve two key properties of wood composites (thickness swelling and fracture toughness). Both experiments and computer simulation (finite element analysis) were carried out to test this hypothesis. I developed a methodology to precisely perforate veneer to facilitate the creation of adhesive Z-connections when the composite was pressed. Adhesive Z-connections are defined as the cured adhesive distributed in the Z- (thickness) direction (in addition to the X-Y directions) of the laminated wood composite due to the perforation in veneer. I examined factors affecting the ability of Z-connections to improve dimensional stability and fracture toughness of a model wood composite. I visualized the adhesive distribution in the composite in 2D and 3D using macro-photography, X-ray micro-computed tomography and scanning electron microscopy. Significant improvements in dimensional stability and fracture toughness of some of the composites were observed. Key parameters affecting the ability of adhesive Z-connections to reduce thickness swelling were diameter and spatial arrangement of Z-connections, adhesive level and wood species used to make the composite. Key parameters affecting the ability of adhesive to increase the fracture toughness of a model wood composite were area-density of Z-connections and reinforcement of the adhesive in the composite. I conclude that introducing adhesive Z-connections can reduce thickness swelling and enhance fracture toughness of wood composites, but the effectiveness of such an approach is affected by wood species, area-density and spatial arrangement of the Z-connections. I discuss the implications of my findings for the development of wood composites with enhanced dimensional stability and fracture toughness and further research needed to capitalize on the concept of creating an inter-connected 3D adhesive network in wood composites by introducing adhesive Z-connections.
Symmetry-breaking transitions in networks of nonlinear circuit elements
Creators: name: Heinrich, Martin
name: Dahms, Thomas
name: Flunkert, Valentin
name: Teitsworth, Stephen W.
name: Schöll, Eckehard
Publisher: name: arXiv
Year: 2010
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We investigate a nonlinear circuit consisting of N tunnel diodes in series, which shows close similarities to a semiconductor superlattice or to a neural network. Each tunnel diode is modeled by a three-variable FitzHugh-Nagumo-like system. The tunnel diodes are coupled globally through a load resistor. We find complex bifurcation scenarios with symmetry-breaking transitions that generate multiple fixed points off the synchronization manifold. We show that multiply degenerate zero-eigenvalue bifurcations occur, which lead to multistable current branches, and that these bifurcations are also degenerate with a Hopf bifurcation. These predicted scenarios of multiple branches and degenerate bifurcations are also found experimentally.
description: 32 pages, 11 figures, 7 movies available as ancillary files
A importância das empresas juniores para incentivar o empreendedorismo durante a formação acadêmica no curso de biotecnologia
Creators: name: Martins, Natália Ornelas
name: Moreira, Eduarda Lara Mendonça
name: Dos Santos, Jhenyfer Benício
name: De Oliveira, Tiago Batista Tomaz
Publisher: name: figshare
Year: 2021
Subjects: Biotechnology

description: Artigo de Opinião: A importância das empresas juniores para incentivar o empreendedorismo durante a formação acadêmica no curso de biotecnologia
The Magellanic Quasars Survey. II. Confirmation of 144 New Active Galactic Nuclei Behind the Southern Edge of the Large Magellanic Cloud
Creators: name: Kozlowski, Szymon
name: Kochanek, C. S.
name: Jacyszyn, A. M.
name: Udalski, A.
name: Szymanski, M. K.
name: Poleski, R.
name: Kubiak, M.
name: Soszynski, I.
name: Pietrzynski, G.
name: Wyrzykowski, L.
name: Ulaczyk, K.
name: Pietrukowicz, P.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We quadruple the number of quasars known behind the Large Magellanic Cloud (LMC) from 55 (42 in the LMC fields of the third phase of the Optical Gravitational Lensing Experiment (OGLE)) to 200 by spectroscopically confirming 169 (144 new) quasars from a sample of 845 observed candidates in four ~3 deg^2 Anglo-Australian Telescope/AAOmega fields south of the LMC center. The candidates were selected based on their Spitzer mid-infrared colors, X-ray emission, and/or optical variability properties in the database of the OGLE microlensing survey. The contaminating sources can be divided into 115 young stellar objects (YSOs), 17 planetary nebulae (PNe), 39 Be and 24 blue stars, 68 red stars, and 12 objects classed as either YSO/PN or blue star/YSO. There are also 402 targets with either featureless spectra or too low signal-to-noise ratio for source classification. Our quasar sample is 50% (30%) complete at I = 18.6 mag (19.3 mag). The newly discovered active galactic nuclei (AGNs) provide many additional reference points for proper motion studies of the LMC, and the sample includes 10 bright AGNs (I < 18 mag) potentially suitable for absorption line studies. Their primary use, however, is for detailed studies of quasar variability, as they all have long-term, high cadence, continuously growing light curves from the microlensing surveys of the LMC. Completing the existing Magellanic Quasars Survey fields in the LMC and Small Magellanic Cloud should yield a sample of ~700 well-monitored AGNs, and expanding it to the larger regions covered by the OGLE-IV survey should yield a sample of ~3600 AGNs.
description: Accepted for publication in ApJ; 15 emulated ApJ pages, 12 figures, 5 tables (1 ASCII table included in the source file); corrected version according to the referee's comments
A flexible inference method for an autoregressive stochastic volatility model with an application to risk management
Creators: name: Xie, Yijun
Publisher: name: University of British Columbia
Year: 2017

description: The Autoregressive Stochastic Volatility (ARSV) model is a discrete-time stochastic volatility model that can model the financial returns time series and volatilities. This model is relevant for risk management. However, existing inference methods have various limitations on model assumptions. In this report we discuss a new inference method that allows flexible model assumption for innovation of the ARSV model. We also present the application of ARSV model to risk management, and compare the ARSV model with another commonly used model for financial time series, namely the GARCH model.
Einstein spacetimes with weak regularity
Creators: name: LeFloch, Philippe G.
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Analysis of PDEs (math.AP)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We review recent work on the Einstein equations of general relativity when the curvature is defined in a weak sense. Weakly regular spacetimes are constructed, in which impulsive gravitational waves, as well as shock waves, propagate.
description: 15 pages
On the infrared behaviour of 3d Chern-Simons theories in N=2 superspace
Creators: name: Leoni, Matias
name: Mauri, Andrea
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss the problem of infrared divergences in the N=2 superspace approach to classically marginal three-dimensional Chern-Simons-matter theories. Considering the specific case of ABJM theory, we describe the origin of such divergences and offer a prescription to eliminate them by introducing non-trivial gauge-fixing terms in the action. We also comment on the extension of our procedure to higher loop order and to general three-dimensional Chern-Simons-matter models.
description: 26 pages, 6 figures, JHEP3; v2: minor corrections and references added; v3: introduction expanded, presentation of section 3.3.1 improved, references added, version to appear in JHEP
Academic identities of international students in a pathway program: perceptions of students and teachers
Creators: name: Kaktins, Louise
Publisher: name: Macquarie University
Year: 2024
Subjects: classificationCode: 399999
subject: Other education not elsewhere classified

description: This dissertation presents a case study exploring the development of academic identities of international students who are non-native-English speakers (NNES) in a for-profit pathway program in Australia designed to facilitate the transition of such students into mainstream university. While the term academic identity is usually interpreted as the identity of academics within the research literature, this thesis applies a different lens to focus on how international students start to develop a sense of their academic self at the outset of their academic studies. The conceptual framework features Social Identity Theory (Tajfel, 1974, 1978; Tajfel & Turner, 1979; Turner et al., 1987) which proposes members in a group acquire status as a consequence of intergroup comparison on the basis of their taking on the positive prototypical preferences of their ingroup, thereby facilitating the acquisition of a robust self-concept or social (academic) identity. The dissertation draws on three lines of empirical data using a mixed methods approach: student surveys, student focus groups, and one-on-one interviews with teachers. Thematic analysis has been applied to qualitative data, and Excel and SPSS software utilised for quantitative data. The dissertation argues that the commercialised framework of the pathway program has specific consequences that can potentially jeopardise the development of an authentic academic identity as students tentatively segue from a learner identity to a more sophisticated academic one. 
The significance of the research is its focus on an under-researched area of the international students’ academic journey, namely the pre-university pathway program which is often their first exposure to a Western style academic environment. As such, it is a defining, high-risk transition period that impacts their future academic success. On a broader level, this dissertation contributes another discrete category of International Student Mobility (ISM) – pre-university mobility – to seminal research in this area (Cairns, 2014a, 2014b, 2015, 2017) to complement already identified categories such as diploma mobility and post-diploma mobility.
“Preparation for Oxidative Stress” a Case of Physiological Conditioning Hormesis?, 2018. Frontiers in psychology
Creators: name: Dos Santos, Jhenyfer Benício
Publisher: name: figshare
Year: 2021
Subjects: Biotechnology

description: “Preparation for Oxidative Stress” a Case of Physiological Conditioning Hormesis?, 2018. Frontiers in psychology.Artigo original escrito por Marcus F. Oliveira, Marcio A. Geihs, Thiago FA França, Daniel C. Moreira, Marcelo Hermes Lima.
Testing the Warm Dark Matter paradigm with large-scale structures
Creators: name: Smith, Robert E.
name: Markovic, Katarina
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We explore the impact of a LWDM cosmological scenario on the clustering properties of large-scale structure in the Universe. We do this by extending the halo model. The new development is that we consider two components to the mass density: one arising from mass in collapsed haloes, and the second from a smooth component of uncollapsed mass. Assuming that the nonlinear clustering of dark matter haloes can be understood, then from conservation arguments one can precisely calculate the clustering properties of the smooth component and its cross-correlation with haloes. We then explore how the three main ingredients of the halo calculations, the mass function, bias and density profiles are affected by WDM. We show that, relative to CDM: the mass function is suppressed by ~50%, for masses ~100 times the free-streaming mass-scale; the bias of low mass haloes can be boosted by up to 20%; core densities of haloes can be suppressed. We also examine the impact of relic thermal velocities on the density profiles, and find that these effects are constrained to scales r<1 kpc/h, and hence of little importance for dark matter tests, owing to uncertainties in the baryonic physics. We use our modified halo model to calculate the non-linear matter power spectrum, and find significant small-scale power in the model. However, relative to the CDM case, the power is suppressed. We then calculate the expected signal and noise that our set of LWDM models would give for a future weak lensing mission. We show that the models should in principle be separable at high significance. Finally, using the Fisher matrix formalism we forecast the limit on the WDM particle mass for a future full-sky weak lensing mission like Euclid or LSST. With Planck priors and using multipoles l<5000, we find that a lower limit of 2.6 keV should be easily achievable.
description: Replaced with version accepted for publication in PRD. Inclusion of: new figure showing dependence of predictions on cut-off mass; new discussion of mass function; updated refs. 18 pages, 10 Figures
On the choice of scoring functions for forecast comparisons
Creators: name: Agyeman, Jonathan
Publisher: name: University of British Columbia
Year: 2017

description: Forecasting of risk measures is an important part of risk management for financial institutions. Value-at-Risk and Expected Shortfall are two commonly used risk measures and accurately predicting these risk measures enables financial institutions to plan adequately for possible losses. Point forecasts from different methods can be compared using consistent scoring functions, provided the underlying functional to be forecasted is elicitable. It has been shown that the choice of a scoring function from the family of consistent scoring functions does not influence the ranking of forecasting methods as long as the underlying model is correctly specified and nested information sets are used. However, in practice, these conditions do not hold, which may lead to discrepancies in the ranking of methods under different scoring functions. We investigate the choice of scoring functions in the face of model misspecification, parameter estimation error and nonnested information sets. We concentrate on the family of homogeneous consistent scoring functions for Value-at-Risk and the pair of Value-at-Risk and Expected Shortfall and identify conditions required for existence of the expectation of these scoring functions. We also assess the finite-sample properties of the Diebold-Mario Test, as well as examine how these scoring functions penalize for over-prediction and under-prediction with the aid of simulation studies.
Doing Phenomenology
Creators: name: Persaud, Balraj
Publisher: name: University of Guelph
Year: 2016
Subjects: subject: Philosophy
subject: FOS: Philosophy, ethics and religion
subject: Contemporary philosophy

description: This Masters thesis is an investigation of the method of phenomenology. Phenomenology is defined and the role of phenomenological description explored. The experience of the method of phenomenology is then explored, followed by a consideration of the role of language in phenomenological description, demonstrating its ability to disturb existing perceptual practices. The thesis concludes by noting the critical capacity and political function of the descriptive method of phenomenology.
Upsilon Production as a Probe for Early State Dynamics in High Energy Nuclear Collisions at RHIC
Creators: name: Liu, Yunpeng
name: Chen, Baoyi
name: Xu, Nu
name: Zhuang, Pengfei
Publisher: name: arXiv
Year: 2010
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Upsilon production in heavy ion collisions at RHIC energy is investigated. While the transverse momentum spectra of the ground state Upsilon(1s) are controlled by the initial state Cronin effect, the excited $b\bar b$ states are characterized by the competition between the cold and hot nuclear matter effects and sensitive to the dissociation temperatures determined by the heavy quark potential. We emphasize that it is necessary to measure the excited heavy quark states in order to extract the early stage information in high energy nuclear collisions at RHIC.
description: 10 pages, 5 figures
Towards a Systematic Construction of Realistic D-brane Models on a del Pezzo Singularity
Creators: name: Dolan, Matthew J.
name: Krippendorf, Sven
name: Quevedo, Fernando
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A systematic approach is followed in order to identify realistic D-brane models at toric del Pezzo singularities. Requiring quark and lepton spectrum and Yukawas from D3 branes and massless hypercharge, we are led to Pati-Salam extensions of the Standard Model. Hierarchies of masses, flavour mixings and control of couplings select higher order del Pezzo singularities, minimising the Higgs sector prefers toric del Pezzos with dP3 providing the most successful compromise. Then a supersymmetric local string model is presented with the following properties at low energies: (i) the MSSM spectrum plus a local B-L gauge field or additional Higgs fields depending on the breaking pattern, (ii) a realistic hierarchy of quark and lepton masses and (iii) realistic flavour mixing between quark and lepton families with computable CKM and PMNS matrices, and CP violation consistent with observations. In this construction, kinetic terms are diagonal and under calculational control suppressing standard FCNC contributions. Proton decay operators of dimension 4, 5, 6 are suppressed, and gauge couplings can unify depending on the breaking scales from string scales at energies in the range 10^{12}-10^{16} GeV, consistent with TeV soft-masses from moduli mediated supersymmetry breaking. The GUT scale model corresponds to D3 branes at dP3 with two copies of the Pati-Salam gauge symmetry SU(4)\timesSU(2)R\timesSU(2)L. D-brane instantons generate a non-vanishing mu-term. Right handed sneutrinos can break the B-L symmetry and induce a see-saw mechanism of neutrino masses and R-parity violating operators with observable low-energy implications.
description: 27 pages plus 5 appendices (42 pages total), 9 figures. v3: equation refs and citation corrected
Quasicircles and Bounded Turning Circles Modulo bi-Lipschitz Maps
Creators: name: Herron, David A.
name: Meyer, Daniel
Publisher: name: arXiv
Year: 2010
Subjects: subject: Complex Variables (math.CV)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 30L10

description: We construct a catalog, of snowflake type metric circles, that describes all metric quasicircles up to \bl\ equivalence. This is a metric space analog of a result due to Rohde. Our construction also works for all bounded turning metric circles; these need not be doubling. As a byproduct, we show that a metric quasicircle with Assouad dimension strictly less than two is bi-Lipschitz equivalent to a planar quasicircle.
description: 30 pages, 3 figures, to appear in Rev. Mat. Iberoamericana
The Proto-Magnetar Model for Gamma-Ray Bursts
Creators: name: Metzger, B. D.
name: Giannios, D.
name: Thompson, T. A.
name: Bucciantini, N.
name: Quataert, E.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Long duration Gamma-Ray Bursts (GRBs) originate from the core collapse of massive stars, but the identity of the central engine remains elusive. Previous work has shown that rapidly spinning, strongly magnetized proto-neutron stars (`millisecond proto-magnetars') produce outflows with energies, timescales, and magnetizations sigma_0 (maximum Lorentz factor) that are consistent with those required to produce long GRBs. Here we extend this work in order to construct a self-consistent model that directly connects the properties of the central engine to the observed prompt emission. Just after the launch of the supernova shock, a wind heated by neutrinos is driven from the proto-magnetar. The outflow is collimated into a bipolar jet by its interaction with the star. As the magnetar cools, the wind becomes ultra-relativistic and Poynting-flux dominated (sigma_0 >> 1) on a timescale comparable to that required for the jet to clear a cavity through the star. Although the site and mechanism of the prompt emission are debated, we calculate the emission predicted by two models: magnetic dissipation and internal shocks. Our results favor the magnetic dissipation model in part because it predicts a relatively constant `Band' spectral peak energy E_peak with time during the GRB. The jet baryon loading decreases abruptly when the neutron star becomes transparent to neutrinos at t ~ 10-100 seconds. Jets with ultra-high magnetization cannot effectively accelerate and dissipate their energy, suggesting this transition ends the prompt emission and may explain the steep decay phase that follows. We assess several phenomena potentially related to magnetar birth, including low luminosity GRBs, thermal-rich GRBs/X-ray Flashes, very luminous supernovae, and short duration GRBs with extended emission.
description: 21 pages (plus 2 appendices), 21 figures, 1 table, now accepted to MNRAS
DB pairs and vanishing theorems
Creators: name: Kovács, Sándor J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14J17

description: The main purpose of this article is to define the notion of DuBois singularities for pairs and proving a vanishing theorem using this new notion. The main vanishing theorem specializes to a new vanishing theorem for resolutions of log canonial singularities.
description: To appear in the Nagata memorial volume of the Kyoto Journal of Mathematics
Weighing of trapped ion crystals and its applications
Creators: name: Sheridan, Kevin
name: Keller, Matthias
Publisher: name: arXiv
Year: 2011
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We have developed a novel scheme to measure the secular motion of trapped ions. Employing pulsed excitation and analysis of the fluorescence of laser cooled ions, we have measured the centre-of-mass mode frequency of single as well as entire ion crystals with a frequency precision better than 5e-4 within an interrogation time on the order of seconds, limited only by the fluorescence collection efficiency and the background noise. We have used this method to measure the mass of ions and observed charge exchange collisions between trapped calcium isotopes.
description: 24 pages, 15 figures
Luminosity Distribution of Gamma-Ray Burst Host Galaxies at redshift z=1 in Cosmological Smoothed Particle Hydrodynamic Simulations: Implications for the Metallicity Dependence of GRBs
Creators: name: Niino, Yuu
name: Choi, Jun-Hwan
name: Kobayashi, Masakazu A. R.
name: Nagamine, Kentaro
name: Totani, Tomonori
name: Zhang, Bing
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study the relationship between the metallicity of gamma-ray burst (GRB) progenitors and the probability distribution function (PDF) of GRB host galaxies as a function of luminosity using cosmological hydrodynamic simulations of galaxy formation. We impose a maximum limit to the gas metallicity in which GRBs can occur, and examine how the predicted luminosity PDF of GRB host galaxies changes in the simulation. We perform the Kolmogorov-Smirnov test, and show that the result from our simulation agrees with the observed luminosity PDF of core-collapse supernovae (SNe) host galaxies when we assume that the core-collapse SNe trace star formation. When we assume that GRBs occur only in a low-metallicity environment with $Z\lesssim 0.1 \Zsun$, GRBs occur in lower luminosity galaxies, and the simulated luminosity PDF becomes quantitatively consistent with the observed luminosity PDF. The observational bias against the host galaxies of optically dark GRBs owing to dust extinction may be another reason for the lower luminosities of GRB host galaxies, but the observed luminosity PDF of GRB host galaxies cannot be reproduced solely by the dust bias in our simulation.
description: 11 pages, 14 figures, minor revisions, one added figure, accepted for publication in ApJ
A genetic basis of adaptation to high pH in Rainbow Trout
Creators: name: McBryan, Tara Lynn
Publisher: name: University of British Columbia
Year: 2017

description: Exposure to high environmental pH is physiologically stressful for fish. In British Columbia, this has led to low survivorship among Rainbow Trout stocked into alkaline lakes. Early studies have shown promising results for stocking the progeny of brood stock collected in high pH lakes into similar alkaline environments. Here I follow up by characterizing the high pH tolerance of fish with parents collected from an alkaline lake, Stump Lake. I also look at the effects of acclimation and rearing fish at pH 8.8 on subsequent pH 9.5 tolerance. I found that this population had a short time to loss of equilibrium, with only 10% of fish remaining after a 3 day exposure to pH 9.5. Acclimation resulted in significant improvements to tolerance and rearing resulted in almost none of the fish losing equilibrium over a 3 day exposure. A genome wide association study on non-acclimated and acclimated individuals did not show any significant genetic marker associations with high pH tolerance. However this analysis did identify some potential SNPs associated with genes involved in acid-base regulation, muscle function, neural signaling, and DNA transcription in the non-acclimated fish. The pH 8.8 acclimated fish only showed association with genes involved in neural signaling and DNA transcription. These data suggest that acclimation may remove limitations associated with some of these other processes. Overall the Stump Lake population does not appear to have genetic adaptations that improve tolerance to high pH exposure, but can improve tolerance through acclimation to moderately high pH.
Capacitive interaction model for Aharonov-Bohm effects of a quantum Hall antidot
Creators: name: Lee, W. -R.
name: Sim, H. -S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We derive a general capacitive interaction model for an antidot-based interferometer in the integer quantum Hall regime, and study Aharonov-Bohm resonances in a single antidot with multiple bound modes, as a function of the external magnetic field or the gate voltage applied to the antidot. The pattern of Aharonov-Bohm resonances is significantly different from the case of noninteracting electrons. The origin of the difference includes charging effects of excess charges, charge relaxation between the bound modes, the capacitive interaction between the bound modes and the extended edge channels nearby the antidot, and the competition between the single-particle level spacing and the charging energy of the antidot. We analyze the patterns for the case that the number of the bound modes is 2, 3, or 4. The results agree with recent experimental data.
description: 9 pages, 6 figures
Water balance of metal mining tailings management facilities : influence of climate conditions and tailings management options
Creators: name: Solgi, Narjes
Publisher: name: University of British Columbia
Year: 2017

description: The objective of this research was done to review and compare available methods for Tailings Management Facilities (TMFs) water balance; to develop deterministic and probabilistic models; and to compare the impacts of different tailings management options and climate conditions. The developed models were spreadsheet based. Mount Polley operational data were used. Water balance models were created for lined and unlined impoundments in both wet and dry climates. Wet condition climate data were extracted from ClimateBC (a University of British Columbia Software Program) using the location of the Kerr-Sulphurets-Mitchell (KSM) project in British Columbia. Climatic data from the Cerro Negro mine site in Argentina were used to simulate the dry condition. After developing a deterministic model, Monte Carlo simulation computational algorithm was used to develop the probabilistic evaluations. Simulations were carried out using the Oracle Crystal Ball Excel add-in. Evaluations were done on four management options (slurry, thickened, paste, and filtered tailings) by changing the tailings solids content. Results confirmed that entrainment and evaporation were the biggest water losses in TMF. For slurry tailings, entrainment loss was more than 80% of the total water loss in the wet condition and more than 50% of the total water loss in the dry condition. The reported average mine water consumption for slurry tailings in arid climate is between 0.4 and 0.7 m³/tonne. The estimated mean required make up water from the developed model in this reaserch was 0.70 m³/tonne. Water withdrawal in dry climate conditions can decrease to 0.18m³/tonne when a filtered tailings option is implemented. The average water surplus in wet climate conditions for an unlined impoundment varied between 0.83 and 1.12 m³/tonne for solids contents between 45% (slurry tailings) and 80% (filtered tailings). The corresponding values for a lined impoundment were 0.86 and 1.16 m³/tonne. Implementing dewatered tailings is not recommended in wet climates. In contrast, paste tailings and filtered tailings are good options in arid areas for proper-size operations. TMFs are site-specific complex systems. Results presented here are only examples to outline how the mining industry can work toward reducing water losses by using dewatering and tailings management technologies.
Hadronic contribution to the muon g-2: a theoretical determination
Creators: name: Bodenstein, S.
name: Dominguez, C. A.
name: Schilcher, K.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The leading order hadronic contribution to the muon g-2, $a_μ^{HAD}$, is determined entirely from theory using an approach based on Cauchy's theorem in the complex squared energy s-plane. This is possible after fitting the integration kernel in $a_μ^{HAD}$ with a simpler function of $s$. The integral determining $a_μ^{HAD}$ in the light-quark region is then split into a low energy and a high energy part, the latter given by perturbative QCD (PQCD). The low energy integral involving the fit function to the integration kernel is determined by derivatives of the vector correlator at the origin, plus a contour integral around a circle calculable in PQCD. These derivatives are calculated using hadronic models in the light-quark sector. A similar procedure is used in the heavy-quark sector, except that now everything is calculable in PQCD, thus becoming the first entirely theoretical calculation of this contribution. Using the dual resonance model realization of Large $N_{c}$ QCD to compute the derivatives of the correlator leads to agreement with the experimental value of $a_μ$. Accuracy, though, is currently limited by the model dependent calculation of derivatives of the vector correlator at the origin. Future improvements should come from more accurate chiral perturbation theory and/or lattice QCD information on these derivatives, allowing for this method to be used to determine $a_μ^{HAD}$ accurately entirely from theory, independently of any hadronic model.
description: Several additional clarifying paragraphs have been added. 1/N_c corrections have been estimated. No change in results
Spectral degeneracy and escape dynamics for intermittent maps with a hole
Creators: name: Froyland, Gary
name: Murray, Rua
name: Stancevic, Ognjen
Publisher: name: arXiv
Year: 2010
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 37E05, 37M25, 37D25

description: We study intermittent maps from the point of view of metastability. Small neighbourhoods of an intermittent fixed point and their complements form pairs of almost-invariant sets. Treating the small neighbourhood as a hole, we first show that the absolutely continuous conditional invariant measures (ACCIMs) converge to the ACIM as the length of the small neighbourhood shrinks to zero. We then quantify how the escape dynamics from these almost-invariant sets are connected with the second eigenfunctions of Perron-Frobenius (transfer) operators when a small perturbation is applied near the intermittent fixed point. In particular, we describe precisely the scaling of the second eigenvalue with the perturbation size, provide upper and lower bounds, and demonstrate $L^1$ convergence of the positive part of the second eigenfunction to the ACIM as the perturbation goes to zero. This perturbation and associated eigenvalue scalings and convergence results are all compatible with Ulam's method and provide a formal explanation for the numerical behaviour of Ulam's method in this nonuniformly hyperbolic setting. The main results of the paper are illustrated with numerical computations.
description: 34 pages
Non-equilibrium phase transition in a periodically driven XY spin chain
Creators: name: Prosen, Tomaz
name: Ilievski, Enej
Publisher: name: arXiv
Year: 2011
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a general formulation of Floquet states of periodically time-dependent open Markovian quasi-free fermionic many-body systems in terms of a discrete Lyapunov equation. Illustrating the technique, we analyze periodically kicekd XY spin 1/2 chain which is coupled to a pair of Lindblad reservoirs at its ends. A complex phase diagram is reported with re-entrant phases of long range and exponentially decaying spin-spin correlations as some of the system's parameters are varied. The structure of phase diagram is reproduced in terms of counting non-trivial stationary points of Floquet quasi-particle dispersion relation.
description: 5 pages in RevTex 4-1, with 3 figures (2 in png and 1 in pdf format) and 1 page of supplementary material
Efimov physics in bosonic atom-trimer scattering
Creators: name: Deltuva, A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Nuclear Theory (nucl-th)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Bosonic atom-trimer scattering is studied in the unitary limit using momentum-space equations for four-particle transition operators. The impact of the Efimov effect on the atom-trimer scattering observables is explored and a number of universal relations is established. Positions and widths of tetramer resonances are determined. Trimer relaxation rate constant is calculated.
description: Added results for the trimer relaxation rate constant