cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Superselection Sectors and General Covariance.I
Creators: name: Brunetti, Romeo
name: Ruzzi, Giuseppe
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: This paper is devoted to the analysis of charged superselection sectors in the framework of the locally covariant quantum field theories. We shall analize sharply localizable charges, and use net-cohomology of J.E. Roberts as a main tool. We show that to any 4-dimensional globally hyperbolic spacetime it is attached a unique, up to equivalence, symmetric tensor $\Crm^*-$category with conjugates (in case of finite statistics); to any embedding between different spacetimes, the corresponding categories can be embedded, contravariantly, in such a way that all the charged quantum numbers of sectors are preserved. This entails that to any spacetime is associated a unique gauge group, up to isomorphisms, and that to any embedding between two spacetimes there corresponds a group morphism between the related gauge groups. This form of covariance between sectors also brings to light the issue whether local and global sectors are the same. We conjecture this holds that at least on simply connected spacetimes. It is argued that the possible failure might be related to the presence of topological charges. Our analysis seems to describe theories which have a well defined short-distance asymptotic behaviour.
description: 66 pages
Local Seed Markets and the Determinants of Crop Variety Diversity in Marginal Environments: The Case of Millet in Semi-Arid India
Creators: name: Nagarajan, Latha
name: Smale, Melinda
name: Glewwe, Paul
name: Nagarajan, Latha
name: Smale, Melinda
name: Glewwe, Paul
Publisher: name: Unknown
Year: 2005
Subjects: Crop Production/Industries

description: The purpose of the research paper is to characterize biological diversity related to millets in the semi-arid regions of India at various spatial scales of analysis (e.g., farm household versus community levels) and place that evidence in a broader seed systems (includes both formal and informal) context. An important finding of this research is that producer access to millet genetic resources is affected by the extent to which seed is traded via formal markets or through other social institutions, along with farm and household characteristics. Findings also underscore the need for an enhanced theoretical understanding of local seed markets in analyzing crop variety choices and the diversity of materials grown in less favored environments.
Constraints on beta functions in field theories
Creators: name: Ma, Han
name: Lee, Sung-Sik
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The $β$-functions describe how couplings run under the renormalization group flow in field theories. In general, all couplings that respect the symmetry and locality are generated under the renormalization group flow, and the exact renormalization group flow is characterized by the $β$-functions defined in the infinite dimensional space of couplings. In this paper, we show that the renormalization group flow is highly constrained so that the $β$-functions defined in a measure zero subspace of couplings completely determine the $β$-functions in the entire space of couplings. We provide a quantum renormalization group-based algorithm for reconstructing the full $β$-functions from the $β$-functions defined in the subspace. As examples, we derive the full $β$-functions for the $O(N)$ vector model and the $O_L(N) \times O_R(N)$ matrix model entirely from the $β$-functions defined in the subspace of single-trace couplings.
description: 75 pages, 12 figures, minor changes
Lejeunea gradsteiniana Pócs
Creators: name: Söderström, Lars
name: Hagborg, Anders
name: Konrat, Matt Von
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Bryophyta
Jungermanniopsida
Porellales
Lejeuneaceae
Lejeunea
Lejeunea gradsteiniana

description: Lejeunea gradsteiniana Pócs,
Acta Biol.Pl.Agr. 1: 55, 2010 [2011] (see Pócs 2010b). NOM. NOV. PRO Ceratolejeunea aberrans Steph., Sp. Hepat. (Stephani) 6: 399, 1923 (see Stephani 1923). BLOCKING NAME: Lejeunea aberrans Lindenb. et Gottsche, Syn. Hepat. 5: 751. 1847 (see Gottsche et al. 1847).
description: Published as part of Söderström, Lars, Hagborg, Anders & Konrat, Matt Von, 2014, Early Land Plants Today: Index of Liverworts & Hornworts 2011 - 2012, pp. 61-85 in Phytotaxa 170 (2) on page 70, DOI: 10.11646/phytotaxa.170.2.1, http://zenodo.org/record/4779611
Existence of principal values of some singular integrals on Cantor sets, and Hausdorff dimension
Creators: name: Cufí, J.
name: Donaire, J. J.
name: Mattila, P.
name: Verdera, J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 42B20 (primary), 30E20 (secondary), 60F17 (secondary)

description: Consider a standard Cantor set in the plane of Hausdorff dimension 1. If the linear density of the associated measure $μ$ vanishes, then the set of points where the principal value of the Cauchy singular integral of $μ$ exists has Hausdorff dimension 1. The result is extended to Cantor sets in $\mathbb{R}^d$ of Hausdorff dimension $α$ and Riesz singular integrals of homogeneity $-α$, 0 < $α$ < d : the set of points where the principal value of the Riesz singular integral of $μ$ exists has Hausdorff dimension $α$. A martingale associated with the singular integral is introduced to support the proof.
description: 14 pages, minor revision after the referee's report, to appear in Pacific J. of Math
Who Participates in EQIP?
Creators: name: McCann, Laura M.J.
name: Nunez, Jennifer
name: McCann, Laura M.J.
name: Nunez, Jennifer
Publisher: name: Unknown
Year: 2005
Subjects: subject: Environmental Economics and Policy
subject: EQIP
subject: adoption
subject: farm size

description: The Environmental Quality Incentive Program is designed to improve environmental stewardship of crop and livestock production. Funds requested through the program greatly exceed the supply. Recent changes make the program more attractive for larger farmers. A survey of farmers in Missouri and Iowa found that larger farmers (in terms of farm sales) and those without a personal concern for water quality in their county are significantly more likely to be aware of EQIP. Those who plan to expand in the next five years, and those who use and trust public information sources, are more likely to be aware of the program and also to participate in EQIP. Age and education variables were not significant.
Static and dynamic critical behaviour of 3d random site Ising model: different Monte Carlo algorithms
Creators: name: Ivaneyko, D.
name: Ilnytskyi, J.
name: Berche, B.
name: Holovatch, Yu.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We perform numerical simulations to study static and dynamic critical behaviour of the 3d random-site Ising model. A distinct feature of our approach is a combination of the Metropolis, Swendsen-Wang, and Wolff Monte Carlo algorithms. For the static critical behaviour, these approaches are the complementary ones, whereas in dynamics they correspond to three different types of relaxation, being a particular subject of our study.
description: Submitted to the Proceedings of the 3rd International Conference "Physics of Liquid Matter: Modern Problems", May 27-31, 2005, Kyiv, Ukraine
Deformed PP-waves from the Lunin-Maldacena Background
Creators: name: Koch, Robert de Mello
name: Murugan, Jeff
name: Smolic, Jelena
name: Smolic, Milena
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this article we study a pp-wave limit of the Lunin-Maldacena background. We show that the relevant string theory background is a homogeneous pp-wave. We obtain the string spectrum. The dual field theory is a deformation of N=4 super Yang-Mills theory. We have shown that, for a class of operators, at O(g_{YM}^2) and at leading order in N, all contributions to the anomalous dimension come from F-terms. We are able to identify the operator in the deformed super Yang-Mills which is dual to the lowest string mode. By studying the undeformed theory we are able to provide some evidence, directly in the field theory, that a small set of nearly protected operators decouple. We make some comments on operators in the Yang-Mills theory that are dual to excited string modes.
description: 22 pages, 1 figure; Final version to appear in JHEP
[Brev til DKNVS]
Creators: name: Riber, Else Marie
name: Det Kongelige Norske Videnskabers Selskab (DKNVS)
Publisher: name: Unknown
Year: 1806

description: Ber om at henne tilkommende renter etter justisråd Hammer blir utbetalt
description: Hun var Hammers husholderske. Polydoc nr. 1: 1039. Polydoc nr. 2: 433.
Epitaxial thin films of binary Eu-compounds close to a valence transition
Creators: name: Kölsch, Sebastian
name: Schuck, Alfons Georg
name: Huth, Michael
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Intermetallic binary compounds of europium reveal a variety of interesting phenomena due to the interconnection between two different magnetic and 4f electronic (valence) states, which are particularly close in energy. The valence states or magnetic properties are thus particularly sensitive to strain-tuning in these materials. Consequently, we grew epitaxial EuPd$_2$ (magnetic Eu$^{2+}$) and EuPd$_3$ (nonmagnetic Eu$^{3+}$) thin films on MgO(001) substrates using molecular beam epitaxy. Ambient X-ray diffraction confirms an epitaxial relationship of cubic Laves-type (C15) EuPd$_2$ with an (111)-out-of-plane orientation, whereby eight distinct in-plane crystallographic domains develop. For simple cubic EuPd$_3$ two different out-of-plane orientations can be obtained by changing the substrate annealing temperature under ultra-high vacuum conditions from 600 °C to 1000 °C for one hour. A small resistance minimum evolves for EuPd$_3$ thin films grown with low temperature substrate annealing, which was previously found even in single crystals of EuPd$_3$ and might be attributed to a Kondo or weak localization effect. Absence of influence of an applied magnetic fields and magnetotransport measurements suggest a nonmagnetic ground state for EuPd$_3$ thin films, i. e., a purely trivalent Eu valence, as found in EuPd$_3$ single crystals. For EuPd$_2$ magnetic ordering below ~72 K is observed, quite similar to single crystal behavior. Field dependent measurements of the magnetoresistance and the Hall effect show hysteresis effects below ~0.4 T and an anomalous Hall effect below ~70 K, which saturates around 1.4 T, thus proving a ferromagnetic ground state of the divalent Eu.
From the voices of experience, the road to recovery
Creators: name: Carson, Joanna Patricia
Publisher: name: University of British Columbia
Year: 2009

description: The individualization and medicalization of the emotional distress of those given psychiatric diagnoses deny the social, political, and economic context in which the presenting behaviours arose and leads away from making changes to society. Some people who are psychiatrically labelled join in groups for solidarity in the face of being stigmatized. In these groups the members can resist the disempowerment and helplessness learned in the psychiatric system. With co-researchers from a self-help group this study gives expression to the usually silenced voices of psychiatrized people. Feminist and standpoint theories, co-cultural and living systems theories form a framework for this narrative study. A structural narrative method is used to analyze the stories, found in the transcripts of six individual interviews, told by the co-researchers about their experiences in psychiatric services and in the recovery process. The stories reveal how the ideology and practices of psychiatry use stigma, oppression and the creation of the identity of psychiatric patient for control and management. The stories also reveal the reality of hope for recovery through the support of peers and from the role models of those who have significantly recovered their mental health. Two focus group interviews were conducted with members of the self-help group where suggestions for programs were developed to address issues raised within the groups and in the individual interviews. The findings of the research will be reported to the self-help group who will use the study to back proposals for the funding of recovery-oriented programs. When social workers and other mental health professsionals recognize the importance of supporting the process of recovery, consumer/survivor-run programs will be acknowledged as effective and integral parts of any mental health system
Statistical Models for the Analysis of Optimization Algorithms with Benchmark Functions
Creators: name: Mattos, David Issa
name: Bosch, Jan
name: Olsson, Helena Holmström
Publisher: name: arXiv
Year: 2020
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Frequentist statistical methods, such as hypothesis testing, are standard practice in papers that provide benchmark comparisons. Unfortunately, these methods have often been misused, e.g., without testing for their statistical test assumptions or without controlling for family-wise errors in multiple group comparisons, among several other problems. Bayesian Data Analysis (BDA) addresses many of the previously mentioned shortcomings but its use is not widely spread in the analysis of empirical data in the evolutionary computing community. This paper provides three main contributions. First, we motivate the need for utilizing Bayesian data analysis and provide an overview of this topic. Second, we discuss the practical aspects of BDA to ensure that our models are valid and the results transparent. Finally, we provide five statistical models that can be used to answer multiple research questions. The online appendix provides a step-by-step guide on how to perform the analysis of the models discussed in this paper, including the code for the statistical models, the data transformations and the discussed tables and figures.
Intrinsic ferroelectric properties of strained tetragonal PbZr0.2Ti0.8O3 obtained on layer-by-layer grown, defect-free single crystalline films
Creators: name: Vrejoiu, Ionela
name: Rhun, Gwenael Le
name: Pintilie, Lucian
name: Hesse, Dietrich
name: Alexe, Marin
name: Goesele, Ulrich
Publisher: name: arXiv
Year: 2006
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: PbZrxTi1-xO3 (PZT) is one of the technologically most important ferroelectric materials. Bulk single-domain single crystals of PZT have never been synthesized for a significant compositional range across the solid-solution phase diagram. This leaves the fundamental properties of PZT under debate. Synthesis of defect-free single crystalline films enables us to unambiguously determine the intrinsic quantities that describe ferroelectric materials, such as spontaneous polarization and dielectric constant. Defect-free single crystalline, strained PbZr0.2Ti0.8O3 thin films were grown by pulsed-laser deposition (PLD) onto vicinal SrTiO3 (001) single crystal substrates. Single crystalline SrRuO3 films fabricated by PLD were employed as bottom electrode. The PZT films have square shape hysteresis loops and remnant polarization values of up to Pr= 110 micro C/cm2, which is considerably higher than the theoretical value predicted for (unstrained) bulk single crystalline PZT of the investigated composition. The films have a dielectric constant eps33= 90 and a piezoelectric coefficient d33= 50 pm/V.
description: 15 pages, 3 figures
Gauge theories and quantum gravity in a finite interval of time, on a compact space manifold
Creators: name: Anselmi, Damiano
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study gauge theories and quantum gravity in a finite interval of time $τ$, on a compact space manifold $Ω$. The initial, final and boundary conditions are formulated in gauge invariant and general covariant ways by means of purely virtual extensions of the theories, which allow us to "trivialize" the local symmetries and switch to invariant fields (the invariant metric tensor, invariant quark and gluon fields, etc.). The evolution operator $U(t_{\text{f}},t_{\text{i}})$ is worked out diagrammatically for arbitrary initial and final states, as well as boundary conditions on $\partial Ω$, and shown to be well defined and unitary for arbitrary $τ=t_{\text{f}}-t_{\text{i}}<\infty $. We illustrate the basic properties in Yang-Mills theory on the cylinder.
description: 52 pages; PRD
EFFICIENCY LOSS AND TRADABLE PERMITS
Creators: name: Liao, Chao-Ning
name: Onal, Hayri
name: Liao, Chao-Ning
name: Onal, Hayri
Publisher: name: Unknown
Year: 2005
Subjects: Environmental Economics and Policy

description: This research presents a price endogenous mathematical programming model that incorporates the independent, optimizing behavior of individual participants to estimate the possible efficiency loss of a newly developed permit trading market for nitrogen oxides (NOx) control in southern Taiwan. The result shows that when control equipment decisions are indivisible, an efficiency loss may arise due to over-investment. The efficiency loss found here is not because of a bilateral trading process and/or insufficient information for finding trading partners, but it is due to not having full control ability of the installed equipment.
Do recent supernovae Ia observations tend to rule out all the cosmologies?
Creators: name: Vishwakarma, Ram Gopal
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Dark energy and the accelerated expansion of the universe have been the direct predictions of the distant supernovae Ia observations which are also supported, indirectly, by the observations of the CMB anisotropies, gravitational lensing and the studies of galaxy clusters. Today these results are accommodated in what has become the `concordance cosmology': a universe with flat spatial sections t=constant with about 70% of its energy in the form of Einstein's cosmological constant Λ. However, we find that as more and more supernovae Ia are observed, more accurately and towards higher redshift, the probability that the data are well explained by the cosmological models decreases alarmingly, finally ruling out the concordance model at more than 95% confidence level. This raises doubts against the `standard candle'-hypothesis of the supernovae Ia and their use to constrain the cosmological models. We need a better understanding of the entire SN Ia phenomenon in order to have cosmological consequences from them.
description: Replaced with published version
Product rigidity in von Neumann and C$^*$-algebras via s-malleable deformations
Creators: name: Drimbe, Daniel
Publisher: name: arXiv
Year: 2020
Subjects: subject: Operator Algebras (math.OA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: We provide a new large class of countable icc groups $\mathcal A$ for which the product rigidity result from [CdSS15] holds: if $Γ_1,\dots,Γ_n\in\mathcal A$ and $Λ$ is any group such that $L(Γ_1\times\dots\timesΓ_n)\cong L(Λ)$, then there exists a product decomposition $Λ=Λ_1\times\dots\times Λ_n$ such that $L(Λ_i)$ is stably isomorphic to $L(Γ_i)$, for any $1\leq i\leq n$. Class $\mathcal A$ consists of groups $Γ$ for which $L(Γ)$ admits an s-malleable deformation in the sense of Sorin Popa and it includes all non-amenable groups $Γ$ such that either (a) $Γ$ admits an unbounded 1-cocycle into its left regular representation, or (b) $Γ$ is an arbitrary wreath product group with amenable base. As a byproduct of these results, we obtain new examples of W$^*$-superrigid groups and new rigidity results in the C$^*$-algebra theory.
description: To appear as such in Communications in Mathematical Physics
Natural Language Processing Specialization: Formula Sheet
Creators: name: Ebeid, Fady Morris Milad
Publisher: name: Zenodo
Year: 2020
Subjects: mathematics
natural language processing
word embeddings
autocorrect
minimum edit distance
hidden markov models
viterbi algorithm
naive bayes
machine learning

description: This is a formula sheet for "Coursera Natural Language Processing Specialization". Natural Language Processing (NLP) uses algorithms to understand and manipulate human language. This technology is one of the most broadly applied areas of machine learning.
On the second homotopy group of spaces of commuting elements in Lie groups
Creators: name: Adem, Alejandro
name: Gómez, José Manuel
name: Gritschacher, Simon
Publisher: name: arXiv
Year: 2020
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics

description: Let $G$ be a compact connected Lie group and $n\geqslant 1$ an integer. Consider the space of ordered commuting $n$-tuples in $G$, $Hom(\mathbb{Z}^n,G)$, and its quotient under the adjoint action, $Rep(\mathbb{Z}^n,G):=Hom(\mathbb{Z}^n,G)/G$. In this article we study and in many cases compute the homotopy groups $π_2(Hom(\mathbb{Z}^n,G))$. For $G$ simply--connected and simple we show that $π_2(Hom(\mathbb{Z}^2,G))\cong \mathbb{Z}$ and $π_2(Rep(\mathbb{Z}^2,G))\cong \mathbb{Z}$, and that on these groups the quotient map $Hom(\mathbb{Z}^2,G)\to Rep(\mathbb{Z}^2,G)$ induces multiplication by the Dynkin index of $G$. More generally we show that if $G$ is simple and $Hom(\mathbb{Z}^2,G)_{1}\subseteq Hom(\mathbb{Z}^2,G)$ is the path--component of the trivial homomorphism, then $H_2(Hom(\mathbb{Z}^2,G)_{1};\mathbb{Z})$ is an extension of the Schur multiplier of $π_1(G)^2$ by $\mathbb{Z}$. We apply our computations to prove that if $B_{com}G_{1}$ is the classifying space for commutativity at the identity component, then $π_4(B_{com}G_{1})\cong \mathbb{Z}\oplus \mathbb{Z}$, and we construct examples of non-trivial transitionally commutative structures on the trivial principal $G$-bundle over the sphere $\mathbb{S}^{4}$.
description: Final version accepted for publication (open access CC-BY) in Int. Math. Res. Not. IMRN
Managing Irrigation Risk with Inflow-Based Derivatives: The Case of Rio Mayo Irrigation District in Sonora, Mexico
Creators: name: Leiva, Akssell J.
name: Skees, Jerry R.
name: Leiva, Akssell J.
name: Skees, Jerry R.
Publisher: name: Unknown
Year: 2005
Subjects: Risk and Uncertainty

description: Uncertain reservoir inflows represent a major source of risk for irrigated agriculture. A derivative instrument that uses reservoir inflows as the underlying variable is designed and tested with a recursive stochastic simulation of the Rio Mayo irrigations system. The results indicate that the instrument effectively protects against downside risk.
Lejeunea gradsteinii G. E. Lee, Damanhuri et Latiff
Creators: name: Söderström, Lars
name: Hagborg, Anders
name: Konrat, Matt Von
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Bryophyta
Jungermanniopsida
Porellales
Lejeuneaceae
Lejeunea
Lejeunea gradsteinii

description: Lejeunea gradsteinii G.E.Lee, Damanhuri et Latiff,
Acta Biol. Pl. Agr. 1: 29, 2010 [2011] (see Lee et al. 2010).
TYPE: “ Malaysia, Sabah, Mt. Kinabalu, trail from Mempening shelter to Layang-Layang staff quarters, montane forest, on tree trunk, 2500–2800 m alt., 12 November 2010, G.E. Lee 1891 (holotype, UKMB; isotype, PC)”.
description: Published as part of Söderström, Lars, Hagborg, Anders & Konrat, Matt Von, 2014, Early Land Plants Today: Index of Liverworts & Hornworts 2011 - 2012, pp. 61-85 in Phytotaxa 170 (2) on page 70, DOI: 10.11646/phytotaxa.170.2.1, http://zenodo.org/record/4779611
Compendium of Remarks, Senior Section Organized Symposium: Opportunities for Economists in Agricultural, Natural Resource, and Rural Development
Creators: name: Farrell, Kenneth R.
name: Farrell, Kenneth R.
Publisher: name: Unknown
Year: 2005
Subjects: Community/Rural/Urban Development

description: Contents Include: Economists in the Development Process: Roles and Responsibilities, by G. Edward Schuh; Agricultural Economists and Rural Economic Development: Some Comments, by Richard P. Taub; Millennium Challenge Corporation: Food Systems, a Framework for Agricultural and Rural Sector Analysis; The Roles of Economists in the Process of Growth: Insights from the Chilean Growth Experience as Seen from the Eyes of a Bolivian, by M. Julio Barragan Arce; Some Thoughts on the Market for Development Jobs, by Nicole Ballenger
The Ellis wormhole with `tachyon matter'
Creators: name: Das, A.
name: Kar, Sayan
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The Ellis wormhole is known to be an exact solution of the Einstein--scalar system where the scalar field has negative kinetic energy (phantom). We show here that the same geometry (in 3+1 dimensions) can also be obtained with `tachyon matter' as a source term in the field equations and a positive cosmological constant. The kink--like tachyon field profile and the nature of the tachyon potential are analyzed. It is shown that the field configuration and the spacetime are stable against linear scalar perturbations. Finally, we comment on extensions of the 3+1 dimensional Ellis wormhole (with tachyon matter source) in diverse dimensions (d=2+1 and d>4).
description: 12 pages, 3 figures, content slightly modified, typos corrected and references added
The Primakoff effect on a proton target
Creators: name: Laget, J. M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Primakoff effect offers us with a way to determine the radiative decay width of pseudo-scalar mesons when they are photo-produced in the electromagnetic field of hadronic systems. Taking advantage of recent developments in the Regge description of the production of mesons in the strong hadronic field, this paper evaluates the relative importance of the electromagnetic and the strong amplitudes, and assesses the possibilities which become opened by modern experimental facilities.
description: 4 pages; 5 Figures
[Brev til DKNVS]
Creators: name: Balhald, E.
name: Det Kongelige Norske Videnskabers Selskab (DKNVS)
Publisher: name: Unknown
Year: 1806

description: Oversender to mynter
description: Transkribsjon vedlagt. Polydoc nr. 1: 1625. Polydoc nr. 2: 1034.
Induced Innovation or a Paradox of Environmental Regulation?
Creators: name: Benson, Aaron
name: Shumway, C. Richard
name: Benson, Aaron
name: Shumway, C. Richard
Publisher: name: Unknown
Year: 2005
Subjects: Environmental Economics and Policy

description: In a seeming paradox, bluegrass seed production in the State of Washington increased following imposition of a statewide ban on stubble burning in 1996. Despite forecasts that alternative production practices would increase the cost of producing bluegrass seed so much that the industry would be driven from the state, production in the years 1997-2003 was higher than in any seven-year period in recorded history. This study seeks to explain why this occurred. Several hypotheses are put forward and systematically tested. The final hypothesis, induced innovation, cannot be formally tested because of data limitations, but it is examined by an assessment of innovations that occurred contemporaneously with the ban and by corroborative statistical evidence. The evidence is consistent with this hypothesis as a plausible explanation.
Sequence Dependence of Electronic Transport in DNA
Creators: name: Rodriguez, Antonio
name: Roemer, Rudolf A.
name: Turner, Matthew S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Genomics (q-bio.GN)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: We study electronic transport in long DNA chains using the tight-binding approach for a ladder-like model of DNA. We find insulating behavior with localizaton lengths xi ~ 25 in units of average base-pair seperation. Furthermore, we observe small, but significant differences between lambda-DNA, centromeric DNA, promoter sequences as well as random-ATGC DNA.
description: 4 pages, 1 figure, Proceedings of "Transport in Interacting and Disordered Systems (TIDS11)", accepted for publication in phys. stat. sol. (b/c), including pss style files
Lejeunea grolleana R. L. Zhu et W. Ye, J. Syst. Evol.
Creators: name: Söderström, Lars
name: Hagborg, Anders
name: Konrat, Matt Von
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Bryophyta
Jungermanniopsida
Porellales
Lejeuneaceae
Lejeunea
Lejeunea grolleana

description: Lejeunea grolleana (Bernecker) R.L.Zhu et W.Ye,
J. Syst. Evol. 51 (4): 472, 2013 [2012] (see Ye et al. 2013). BASIONYM: Oryzolejeunea grolleana Bernecker, Haussknechtia, Beih. 9: 37, 1999 (see Bernecker-Lücking 1999). NOTE: The combination was invalidly published twice prior to the valid publication (Zhu et al. 2011b: 46, Ye & Zhu 2012: 83, non vidi).
description: Published as part of Söderström, Lars, Hagborg, Anders & Konrat, Matt Von, 2014, Early Land Plants Today: Index of Liverworts & Hornworts 2011 - 2012, pp. 61-85 in Phytotaxa 170 (2) on page 70, DOI: 10.11646/phytotaxa.170.2.1, http://zenodo.org/record/4779611
A proof of Brouwer's toughness conjecture
Creators: name: Gu, Xiaofeng
Publisher: name: arXiv
Year: 2020
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05C42, 05C50

description: The toughness $t(G)$ of a connected graph $G$ is defined as $t(G)=\min\{\frac{|S|}{c(G-S)}\}$, in which the minimum is taken over all proper subsets $S\subset V(G)$ such that $c(G-S)>1$, where $c(G-S)$ denotes the number of components of $G-S$. Let $λ$ denote the second largest absolute eigenvalue of the adjacency matrix of a graph. For any connected $d$-regular graph $G$, it has been shown by Alon that $t(G)>\frac{1}{3}(\frac{d^2}{dλ+λ^2}-1)$, through which, Alon was able to show that for every $t$ and $g$ there are $t$-tough graphs of girth strictly greater than $g$, and thus disproved in a strong sense a conjecture of Chvátal on pancyclicity. Brouwer independently discovered a better bound $t(G)>\frac{d}λ-2$ for any connected $d$-regular graph $G$, while he also conjectured that the lower bound can be improved to $t(G)\ge \frac{d}λ - 1$. We confirm this conjecture.
QFactor: A Domain-Specific Optimizer for Quantum Circuit Instantiation
Creators: name: Kukliansky, Alon
name: Younis, Ed
name: Cincio, Lukasz
name: Iancu, Costin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce a domain-specific algorithm for numerical optimization operations used by quantum circuit instantiation, synthesis, and compilation methods. QFactor uses a tensor network formulation together with analytic methods and an iterative local optimization algorithm to reduce the number of problem parameters. Besides tailoring the optimization process, the formulation is amenable to portable parallelization across CPU and GPU architectures, which is usually challenging in general purpose optimizers (GPO). Compared with several GPOs, our algorithm achieves exponential memory and performance savings with similar optimization success rates. While GPOs can handle directly circuits of up to six qubits, QFactor can process circuits with more than 12 qubits. Within the BQSKit optimization framework, we enable optimizations of 100+ qubit circuits using gate deletion algorithms to scale out linearly with the hardware resources allocated for compilation in GPU environments.
description: 11 pages, 8 figures
Micro-evaporators for kinetic exploration of phase diagrams
Creators: name: Leng, Jacques
name: Lonetti, Barbara
name: Tabeling, Patrick
name: Joanicot, Mathieu
name: Ajdari, Armand
Publisher: name: arXiv
Year: 2006
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We use pervaporation-based microfluidic devices to concentrate species in aqueous solutions with spatial and temporal control of the process. Using experiments and modelling, we quantitatively describe the advection-diffusion behavior of the concentration field of various solutions (electrolytes, colloids, etc) and demonstrate the potential of these devices as universal tools for the kinetic exploration of the phases and textures that form upon concentration.
Undecidability in quantum thermalization
Creators: name: Shiraishi, Naoto
name: Matsumoto, Keiji
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The investigation of thermalization in isolated quantum many-body systems has a long history, dating back to the time of developing statistical mechanics. Most quantum many-body systems in nature are considered to thermalize, while some never achieve thermal equilibrium. The central problem is to clarify whether a given system thermalizes, which has been addressed previously, but not resolved. Here, we show that this problem is undecidable. The resulting undecidability even applies when the system is restricted to one-dimensional shift-invariant systems with nearest-neighbour interaction, and the initial state is a fixed product state. We construct a family of Hamiltonians encoding dynamics of a reversible universal Turing machine, where the fate of a relaxation process changes considerably depending on whether the Turing machine halts. Our result indicates that there is no general theorem, algorithm, or systematic procedure determining the presence or absence of thermalization in any given Hamiltonian.
description: 6 pages, 3 figures. See our long companion paper arXiv:2012.13890 )
Pseudo-$C_\ell$ estimators which do not mix E and B modes
Creators: name: Smith, Kendrick M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Pseudo-$C_\ell$ quadratic estimators for CMB temperature and polarization power spectra have been used in the analysis pipelines of many CMB experiments, such as WMAP and Boomerang. In the polarization case, these estimators mix E and B modes, in the sense that the estimated B-mode power is nonzero for a noiseless CMB realization which contains only E-modes. Recently, Challinor & Chon showed that for moderately sized surveys ($f_{sky} \sim 0.01$), this mixing limits the gravity wave B-mode signal which can be detected using pseudo-$C_\ell$ estimators to $T/S \sim 0.05$. We modify the pseudo-$C_\ell$ construction, defining ``pure'' pseudo-$C_\ell$ estimators, which do not mix E and B modes in this sense. We study these estimators in detail for a survey geometry similar to that which has been proposed for the QUIET experiment, for a variety of noise levels, and both homogeneous and inhomogeneous noise. For noise levels $\simle 20$ $μ$K-arcmin, our modification significantly improves the B-mode power spectrum errors obtained using pseudo-$C_\ell$ estimators. In the homogeneous case, we compute optimal power spectrum errors using a Fisher matrix approach, and show that our pure pseudo-$C_\ell$ estimators are roughly 80% of optimal, across a wide range of noise levels. There is no limit, imposed by the estimators alone, to the value of $T/S$ which can be detected.
description: 23 pages, 7 figures, PRD submitted
[Brev til DKNVS]
Creators: name: Schimmelmann, Ernst Heinrich
name: Det Kongelige Norske Videnskabers Selskab (DKNVS)
Publisher: name: Unknown
Year: 1806

description: Schimmelmann svarer på VS brev av 18/3 1806 og beklager at pengene til premier ikke er sendt tidligere grunnet dødsboets oppgjør
description: Også undertegnet av Christian Cold. Polydoc nr. 1: 1054. Polydoc nr. 2: 448.
Resistivity tensor of vortex-lattice states in Josephson junction arrays
Creators: name: Penner, Alexander-Georg
name: Flensberg, Karsten
name: Glazman, Leonid I.
name: von Oppen, Felix
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Two-dimensional Josephson junction arrays frustrated by a perpendicular magnetic field are predicted to form a cascade of distinct vortex lattice states. Here, we show that the resistivity tensor provides both structural and dynamical information on the vortex-lattice states and intervening phase transitions, which allows for experimental identification of these symmetry-breaking ground states. We illustrate our general approach by a microscopic theory of the resistivity tensor for a range of magnetic fields exhibiting a rich set of vortex lattices as well as transitions to liquid-crystalline vortex states.
description: 5+3 pages, 5 figures
THE RISE AND DECLINE OF RENT-SEEKING ACTIVITY IN THE BRAZILIAN COFFEE SECTOR: LESSONS FROM THE IMPOSITION AND REMOVAL OF COFFEE EXPORT QUOTAS
Creators: name: Jarvis, Lovell S.
name: Jarvis, Lovell S.
Publisher: name: Unknown
Year: 2004
Subjects: subject: International Relations/Trade
subject: South America
subject: Brazil
subject: International Coffee Agreement
subject: rent seeking
subject: export tax rebates

description: Brazil, the world's largest coffee exporter, encouraged efforts in the 1960s to form the International Coffee Agreement (ICA), which restricted total coffee exports via country export quotas. The quotas led to significant domestic quota rents in producing countries. This paper analyzes the effects of rent seeking in Brazil. The Brazilian Institute of Coffee (IBC), which was responsible for coffee policy, was the focus of rent seeking. The paper models the policy instruments used by the IBC, shows how rent seeking affected policy, industry efficiency and the distribution of rents, explains the causes and effects of IBC reforms in the late 1980s, and draws lessons from the experience.
[Brev til DKNVS]
Creators: name: Danske Kanselli
name: Det Kongelige Norske Videnskabers Selskab (DKNVS)
Publisher: name: Unknown
Year: 1806

description: Kanselliet besvarer VS' skriv av 25/3 1806 vedr. pengeproblemene i VS
description: Undertegnet av Cold, Berner og to andre. Polydoc nr. 1: 1055. Polydoc nr. 2: 449.
COMPARATIVE STATICS OF MONEY-GOODS SPECIFICATIONS OF THE UTILITY FUNCTION
Creators: name: Paris, Quirino
name: Caputo, Michael R.
name: Paris, Quirino
name: Caputo, Michael R.
Publisher: name: Unknown
Year: 2001
Subjects: Research Methods/ Statistical Methods

description: The introduction of real-cash balances into the neoclassical model of the consumer wrecks havoc, in general, on the empirically observable refutable comparative statics properties of the model. We provide the most general solution of this problem to date by deriving a symmetric and negative semidefinite generalized Slutsky matrix that is empirically observable and which contains all other such comparative statics results as a special case. In addition, we clarify and correct two aspects of Samuelson and Sato's (1984) treatment of this problem.
Stickiness in mushroom billiards
Creators: name: Altmann, Eduardo G.
name: Motter, Adilson E.
name: Kantz, Holger
Publisher: name: arXiv
Year: 2005
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate dynamical properties of chaotic trajectories in mushroom billiards. These billiards present a well-defined simple border between a single regular region and a single chaotic component. We find that the stickiness of chaotic trajectories near the border of the regular region occurs through an infinite number of marginally unstable periodic orbits. These orbits have zero measure, thus not affecting the ergodicity of the chaotic region. Notwithstanding, they govern the main dynamical properties of the system. In particular, we show that the marginally unstable periodic orbits explain the periodicity and the power-law behavior with exponent $γ=2$ observed in the distribution of recurrence times.
description: 7 pages, 6 figures (corrected version with a new figure)
Undecidability of the fate of relaxation in one-dimensional quantum systems
Creators: name: Shiraishi, Naoto
name: Matsumoto, Keiji
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the relaxation dynamics in an isolated quantum many-body system. The stationary value of an observable after relaxation is a topic of researches in the field of quantum thermalization, since thermalization is a relaxation phenomena where this stationary value coincides with the equilibrium value. Therefore, computing the stationary value in quantum many-body systems is regarded as an important problem. We, however, prove that the stationary value in quantum many-body systems is incomputable. More precisely, we show that whether the stationary value is in the vicinity of a given value or not is an undecidable problem. Our undecidable result is still satisfied when we restrict our system to a one-dimensional shift-invariant system with nearest-neighbor interaction, our initial state to a product state of a state on a single site, and our observable to a shift-sum of a one-body observable. This result clearly shows that there is no general theorem or procedure to decide the presence or absence of thermalization in a given quantum many-body system.
description: 41 pages, 8 figures. See our shorter companion paper arXiv:2012.13889
Assessment of the structure and function of kainate-type glutamate receptors GluR6
Creators: name: Mohammadi, Shahin
Publisher: name: University of British Columbia
Year: 2009

description: Glutamate is the main excitatory neurotransmitter in the brain and is essential in most physiological processes. Recent evidence .indicates that the structure of ionotropic glutamate receptors (GluRs) is unique among the ligand-gated ion channel superfamily. The C-terminus of GluR is intra- rather than extracellular and the pore forming segment (M2) forms a hairpin structure in the membrane. In addition, several studies indicate that the M3-M4 loop (the segment connecting transmembrane 3 and 4) is extracellular. However, other studies suggest that residues within the M3-M4 loop are sites of phosphorylation and modulation of channel function by intracellular protein kinases, and therefore the loop is intracellular. To reconcile these conflicting data, we hypothesized that GluR may have a dynamic structure in which, upon agonist binding to and activation of the channel, a portion of the M3-M4 loop containing putative phosphorylation sites translocates across the membrane to the cytosolic side. In order to test this hypothesis, we used site directed mutagenesis to mutate a putative PKA phosphorylation site located in M3-M4 loop of GluR6 (Ser684) to Cys, allowing further modification of this residue by Cys-specific reagents. Using a combined biochemical and electrophysiological approach, we determined that in the Hgand-unbound state of GluR6(S684C), Cys-684 is accessible from the extracellular side to modification by a Cys-specific biotinylating reagent as well as by streptavidin. In addition, we found that this residue becomes inaccessible for biotinylation upon agonist binding and activation of the channel. However, our electrophysiological data indicate that translocation of C684 to the cytoplasmic side is unlikely. The results of our biochemical and electrophysiological experiments indicate that residue 684 in the M3-M4 loop is located extracellularly in the channel's ligand unbound, closed state, as well as ligand-bound, activated or desensitized state. In addition, we analyzed the role of cysteine residues in the normal function of GluR6 receptors. Cys-residues have been shown to be important in the function of several ligand-gated ion channels. Our data indicate that cysteine residues within the M3-M4 loop and N-terminal region contribute to the function and pharmacological properties of GluR6 receptors. Mutation of GluR6 Cys-719 to serine or threonine (C719S, C719T) resulted in a change in the EC50 for glutamate and slowed desensitization of the channel. Other mutations (C773S, C316S and C719S/C773S) resulted in loss of protein expression. Moreover, our data suggest that Cys-719 and Cys-65 form disulfide bonds with other cysteine residues in the M3-M4 loop and N-terminal part of the receptor. These results increase our understanding of the structure and function of glutamate receptors and may prove useful in development of drugs specific for glutamate receptor subunits.
Lejeunea hawaikiana M. A. M. Renner et de Lange
Creators: name: Söderström, Lars
name: Hagborg, Anders
name: Konrat, Matt Von
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Bryophyta
Jungermanniopsida
Porellales
Lejeuneaceae
Lejeunea
Lejeunea hawaikiana

description: Lejeunea hawaikiana M.A.M.Renner et de Lange,
New Zealand J. Bot. 49 (3): 431, 2011 (see Renner & de Lange 2011). NOM. NOV. PRO Stenolejeunea acuminata R.M.Schust., J. Hattori Bot. Lab. 89: 156, 2000 (see Schuster 2000).
description: Published as part of Söderström, Lars, Hagborg, Anders & Konrat, Matt Von, 2014, Early Land Plants Today: Index of Liverworts & Hornworts 2011 - 2012, pp. 61-85 in Phytotaxa 170 (2) on page 70, DOI: 10.11646/phytotaxa.170.2.1, http://zenodo.org/record/4779611
Dynamic properties of cyclic cosmologies
Creators: name: Pavlović, Petar
name: Sossich, Marko
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Our first goal in this work is to study general and model-independent properties of cyclic cosmologies. The large number of studies of bouncing cosmologies and different cyclic scenarios published recently calls for a proper understanding of the universal properties of cyclic models. We thus first review and further elaborate the common physical and geometrical properties of various classes of cyclic models and then discuss how cyclic Universe can be treated as a dynamic system. We then discuss how two theorems from dynamic systems analysis can be used to ensure the existence of cyclic cosmological solutions under certain conditions on the field equations. After this we proceed towards our second goal which is the application of the obtained results to different frameworks of modified gravity theories: $f(R)$ gravity, dynamic dark energy and $f(T)$ gravity. We discuss the general requirements for the existence of cyclic solutions in these theories and also obtain various examples of cyclic cosmologies, while discussing their basic properties.
description: 45 pages, 6 figures