cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Three-loop soft function for energetic electroweak boson production at hadron colliders
Creators: name: Liu, Ze Long
name: Stahlhofen, Maximilian
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We calculate the three-loop soft function for the production of an electroweak boson (Higgs, $γ$, $W^\pm$, $Z$) with large transverse momentum at a hadron collider. It is the first time a soft function for a three-parton process is computed at next-to-next-to-next-to-leading order (N$^3$LO). As a technical novelty, we perform the calculation in terms of forward-scattering-type loop diagrams rather than evaluating phase space integrals. Our three-loop result contains color-tripole contributions and explicitly confirms predictions on the universal infrared structure of QCD scattering amplitudes with three massless parton legs. The soft function is a central ingredient in the factorized cross section for electroweak boson production near the kinematic endpoint (threshold), where the invariant mass of the recoiling hadronic radiation is small compared to its transverse momentum. Our result is required for predictions of the near-threshold cross sections at N$^3$LO and for the resummation of threshold logarithms at primed next-to-next-to-next-to-leading logarithmic (N$^3$LL$^\prime$) accuracy.
description: 31 pages, 5 figures; v2: journal version
SENSITIVITY OF GROSS STATE PRODUCT TO CYCLICAL AND STRUCTURAL CHANGE
Creators: name: Maki, Wilbur R.
name: Jutila, Sakari T.
name: Maki, Wilbur R.
name: Jutila, Sakari T.
Publisher: name: Unknown
Year: 1988
Subjects: Community/Rural/Urban Development

description: The sensitivity of regional industry to business cycles has been widely documented. Responses of individual businesses and industries in a specific region or state to each phase of the business cycle has been less well analyzed and understood. Lacking in all the documentation, moreover, is reference to the impact of business cycles on interregional trade and regional interindustry structure and to the separation of these impacts from those due to business activity location and dislocation. To deal with these limitations, state-level location quotient and shift-share analyses of year-to-year changes in industry-specific contribution to gross state product are used in differentiating the varying degrees of cyclical sensitivity among industries and regions and then, in later studies, to account for these differences in parallel analyses of the structure of inter-regional trade and interindustry transactions among selected groups of states. A micro-to-macro analytical framework is offered, finally, for testing working hypotheses pertaining to the sensitivity of businesses, industries and regions to the business cycle and to structural dislocation.
Categorical models of Linear Logic with fixed points of formulas
Creators: name: Ehrhard, Thomas
name: Jafarrahmani, Farzad
Publisher: name: arXiv
Year: 2020
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: We develop a denotational semantics of muLL, a version of propositional Linear Logic with least and greatest fixed points extending David Baelde's propositional muMALL with exponentials. Our general categorical setting is based on the notion of Seely category and on strong functors acting on them. We exhibit two simple instances of this setting. In the first one, which is based on the category of sets and relations, least and greatest fixed points are interpreted in the same way. In the second one, based on a category of sets equipped with a notion of totality (non-uniform totality spaces) and relations preserving them, least and greatest fixed points have distinct interpretations. This latter model shows that muLL enjoys a denotational form of normalization of proofs.
description: arXiv admin note: text overlap with arXiv:1906.05593
General class of wormhole geometries in conformal Weyl gravity
Creators: name: Lobo, Francisco S. N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this work, a general class of wormhole geometries in conformal Weyl gravity is analyzed. A wide variety of exact solutions of asymptotically flat spacetimes is found, in which the stress energy tensor profile differs radically from its general relativistic counterpart. In particular, a class of geometries is constructed that satisfies the energy conditions in the throat neighborhood, which is in clear contrast to the general relativistic solutions.
description: 7 pages, Revtex4. V2: typos corrected. V3: 8 pages, section on the energy conditions added, version to appear in Class. Quant. Gravity
Design of high frequency inductive power transfer systems for integration into applications
Creators: name: Arteaga Saenz, Juan Manuel
Publisher: name: Imperial College London
Year: 2019

description: High frequency inductive power transfer (HF-IPT) is a technology with the potential of enabling wireless power to existing and emerging battery powered devices across multiple domains, such as consumer electronics, health-care, electric transport, security and defence. For over a decade, research groups around the world have managed to demonstrate HF-IPT as a proof of concept; however, the lack of presence of the technology in medium or high power commercial products highlights the difficulty of integrating it into real world scenarios. This thesis is concerned, primarily, with the interaction and trade-offs between the power conversion stages of HF-IPT systems, ranging from the mains to the battery. The system model is structured so that crucial features for commercial exploitation, such as tolerance to misalignment and tolerance to load variation, are considered at each individual stage. Firstly, existing and novel candidate high-frequency power converters are proposed and prototyped to deal with challenges that emerge depending in the application at hand. With these prototype converter blocks, experimental work at the system level includes achieving 88% DC-DC efficiency at 6.78MHz and an air-gap of one coil radius. This, to the author's knowledge is the highest end-to-end effciency achieved in HF-IPT under similar circumstances. Experiments also demonstrate a system architecture, introduced herein, where Class E and Class EF inverters are fed directly from the mains to eliminate one power conversion stage at the transmit side when the mains interface is taken into account. A technique for HF-IPT design is then introduced with the formulation of a probability-based model which include motion and spatial freedom as design variables, allowing not only for the system to be designed and assessed for variable coupling, but also to consider the motion profile of the device being charged in the system optimisation. Two HF-IPT systems powering an application are then demonstrated. The first consists of wireless power to a drone without a battery while it hovers over a charging-pad, and the second, wireless charging of an electric scooter. These demonstrations were made possible by implementing the main contributions of this work.
Continual Prototype Evolution: Learning Online from Non-Stationary Data Streams
Creators: name: De Lange, Matthias
name: Tuytelaars, Tinne
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Attaining prototypical features to represent class distributions is well established in representation learning. However, learning prototypes online from streaming data proves a challenging endeavor as they rapidly become outdated, caused by an ever-changing parameter space during the learning process. Additionally, continual learning does not assume the data stream to be stationary, typically resulting in catastrophic forgetting of previous knowledge. As a first, we introduce a system addressing both problems, where prototypes evolve continually in a shared latent space, enabling learning and prediction at any point in time. In contrast to the major body of work in continual learning, data streams are processed in an online fashion, without additional task-information, and an efficient memory scheme provides robustness to imbalanced data streams. Besides nearest neighbor based prediction, learning is facilitated by a novel objective function, encouraging cluster density about the class prototype and increased inter-class variance. Furthermore, the latent space quality is elevated by pseudo-prototypes in each batch, constituted by replay of exemplars from memory. As an additional contribution, we generalize the existing paradigms in continual learning to incorporate data incremental learning from data streams by formalizing a two-agent learner-evaluator framework. We obtain state-of-the-art performance by a significant margin on eight benchmarks, including three highly imbalanced data streams.
description: 10 pages, code publicly available
Dark Matter and The Anthropic Principle
Creators: name: Hellerman, Simeon
name: Walcher, Johannes
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We evaluate the problem of galaxy formation in the landscape approach to phenomenology of the axion sector. With other parameters of standard LambdaCDM cosmology held fixed, the density of cold dark matter is bounded below relative to the density of baryonic matter by the requirement that structure should form before the era of cosmological constant domination of the universe. Galaxies comparable to the Milky Way can only form if the ratio also satisfies an upper bound. The resulting constraint on the density of dark matter is too loose to select a low axion decay constant or small initial displacement angle on anthropic grounds.
description: 17 pages, 1 figure
title: Problemy dostępności budynków oświaty w województwie wielkopolskim na wybranych przykładach
Creators: name: Rakowicz, Matylda
name: Gawlak, Agata
Publisher: name: Publishing House of Poznan University of Technology
Year: 2023

description: Zeszyty Naukowe Politechniki Poznańskiej. Architektura, Urbanistyka, Architektura Wnętrz, 15, 363-386
The J1-J2 model: First order phase transition versus deconfinement of spinons
Creators: name: Sirker, J.
name: Weihong, Zheng
name: Sushkov, O. P.
name: Oitmaa, J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We revisit the phase transition from the Néel ordered to a valence bond solid (VBS) state in the two-dimensional $J_1-J_2$ antiferromagnetic Heisenberg model. In the first part we address the question whether or not this transition could be an example of a second order phase transition due to a deconfinement of spinons. We give arguments based on series expansion and spin-wave theory that this is not the case and the transition is most likely first order. The method proposed here to detect first order phase transitions seems to be very sensitive and might be useful in other models as well. In the second part we analyze possible VBS patterns in the magnetically disordered phase based on numerical data for different susceptibilities, obtained in the ordered phase, which test the breaking of lattice symmetries. We conclude that a columnar dimerization pattern is the most likely candidate.
description: 7 pages, 7 figures, small changes, references added
Ostenocaris Arduini, Pinna & Teruzzi 1984
Creators: name: Laville, Thomas
name: Forel, Marie-Béatrice
name: Charbonnier, Sylvain
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Ostenocarididae
Ostenocaris

description: Genus Ostenocaris Arduini, Pinna & Teruzzi, 1984
Type species
Ostenia cypriformis Arduini, Pinna & Teruzzi, 1980 by monotypy.
Diagnosis
Thylacocephalan with a sinuous anterior margin ending in a sharp antero-dorsal corner. Large oval eyes protruding from the anterior margin. Medio and dorso-lateral carina present on the shield. Large raptorial appendages bearing short spines.
Other included species
Ostenocaris ribeti (Secrétan, 1985) comb. nov. – Callovian, Middle Jurassic, France.
Remarks
Arduini et al (1980) did not provide a diagnosis for Ostenocaris. They just mentioned that the description of Ostenocaris was “coinciding with that of the type species” (Arduini et al. 1980: 362). Concerning the type species, they just described the original species without providing a proper diagnosis.
description: Published as part of Laville, Thomas, Forel, Marie-Béatrice & Charbonnier, Sylvain, 2023, Re-appraisal of thylacocephalans (Euarthropoda, Thylacocephala) from the Jurassic La Voulte-sur-Rhône Lagerstätte, pp. 1-61 in European Journal of Taxonomy 898 (1) on page 25, DOI: 10.5852/ejt.2023.898.2295, http://zenodo.org/record/8413500
Symmetry Breaking Differential Operators for Tensor Products of Spinorial Representations
Creators: name: Clerc, Jean-Louis
name: Koufany, Khalid
Publisher: name: arXiv
Year: 2020
Subjects: subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: Primary 43A85, Secondary 58J70, 33J45

description: Let $\mathbb S$ be a Clifford module for the complexified Clifford algebra $\mathbb{C}\ell(\mathbb R^n)$, $\mathbb S'$ its dual, $ρ$ and $ρ'$ be the corresponding representations of the spin group ${\rm Spin}(n)$. The group $G= {\rm Spin}(1,n+1)$ is a (twofold) covering of the conformal group of $\mathbb R^n$. For $λ, μ\in \mathbb C$, let $π_{ρ, λ}$ (resp. $π_{ρ',μ}$) be the spinorial representation of $G$ realized on a (subspace of) $C^\infty(\mathbb R^n,\mathbb S)$ (resp. $C^\infty(\mathbb R^n,\mathbb S')$). For $0\leq k\leq n$ and $m\in \mathbb N$, we construct a symmetry breaking differential operator $B_{k;λ,μ}^{(m)}$ from $C^\infty(\mathbb R^n \times \mathbb R^n,\mathbb{S}\,\otimes\, \mathbb{S}')$ into $C^\infty(\mathbb R^n, Λ^*_k(\mathbb R^n) \otimes \mathbb{C})$ which intertwines the representations $π_{ρ, λ}\otimes π_{ρ',μ} $ and $π_{τ^*_k,λ+μ+2m}$, where $τ^*_k$ is the representation of ${\rm Spin}(n)$ on the space $Λ^*_k(\mathbb R^n) \otimes \mathbb{C}$ of complex-valued alternating $k$-forms on $\mathbb{R}^n$.
Evolution of topological order in Xe films on a quasicrystal surface
Creators: name: Curtarolo, Stefano
name: Setyawan, Wahyu
name: Ferralis, Nicola
name: Diehl, Renee D.
name: Cole, Milton W.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We report results of the first computer simulation studies of a physically adsorbed gas on a quasicrystalline surface, Xe on decagonal Al-Ni-Co. The grand canonical Monte Carlo method is employed, using a semi-empirical gas-surface interaction, based on conventional combining rules, and the usual Lennard-Jones Xe-Xe interaction. The resulting adsorption isotherms and calculated structures are consistent with the results of LEED experimental data. The evolution of the bulk film begins in the second layer, while the low coverage behavior is epitaxial. This transition from 5-fold to 6-fold ordering is temperature dependent, occurring earlier (at lower coverage) for the higher temperatures.
THE CRANE LAKE CONNECTION
Creators: name: Blank, Uel
name: Larsen, Dayton
name: Simonson, Lawrence R.
name: Blank, Uel
name: Larsen, Dayton
name: Simonson, Lawrence R.
Publisher: name: Unknown
Year: 1977
Subjects: Resource /Energy Economics and Policy

description: The purpose of this report is two-fold: (1) to provide current estimates of the recreational activities, or uses in the newly-established Voyageurs National Park that are dependent upon Crane Lake as a means of access or source of supplies, (2) to examine Crane Lake as an operating community in relationship to its physical resource base, its service to the larger society, and to the public services and agencies with which it must interact.
Plane fronted gravitational waves in Lovelock-Yang-Mills theory
Creators: name: Gleiser, Reinaldo J.
name: Dotti, Gustavo
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We obtain plane fronted gravitational waves (PFGWs) in arbitrary dimension in Lovelock gravity, to any order in the Riemann tensor. We exhibit pure gravity as well as Lovelock-Yang-Mills PFGWs. Lovelock-Maxwell and $pp$ waves arise as particular cases. The electrovac solutions trivially satisfy the Lovelock-Born-Infeld field equations. The peculiarities that arise in degenerate Lovelock theories are also analyzed.
description: 11 pages
Interaction-induced topological phase transition and Majorana edge states in low-dimensional orbital-selective Mott insulators
Creators: name: Herbrych, J.
name: Środa, M.
name: Alvarez, G.
name: Mierzejewski, M.
name: Dagotto, E.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Topological phases of matter are among the most intriguing research directions in Condensed Matter Physics. It is known that superconductivity induced on a topological insulator's surface can lead to exotic Majorana modes, the main ingredient of many proposed quantum computation schemes. In this context, the iron-based high critical temperature superconductors are a promising platform to host such an exotic phenomenon in real condensed-matter compounds. The Coulomb interaction is commonly believed to be vital for the magnetic and superconducting properties of these systems. This work bridges these two perspectives and shows that the Coulomb interaction can also drive a canonical superconductor with orbital degrees of freedom into the topological state. Namely, we show that above a critical value of the Hubbard interaction the system simultaneously develops spiral spin order, a highly unusual triplet amplitude in superconductivity, and, remarkably, Majorana fermions at the edges of the system.
Do Taxes on Large Firms Impede Growth? Evidence from Ghana
Creators: name: Gollin, Douglas
name: Gollin, Douglas
Publisher: name: Unknown
Year: 1995
Subjects: Public Economics

description: Many developing countries pursue policies that treat large and small firms differently. For example, large firms may be subject to a value added tax while small firms are explicitly exempted. Moreover, governments often find it impractical to collect taxes from the smallest enterprises; this may increase the tax burden for larger firms, whose compliance can be enforced. Such policies clearly affect the size distribution of firms. But how great is the impact on macro variables? How large are the resulting inefficiencies? And what are the dynamic effects on capital accumulation and economic growth? This paper uses a dynamic general equilibrium variant of the Lucas (1978) span-of-control model to address such questions. The model is matched to data from the Ghanaian manufacturing sector. As a policy experiment, alternative tax and regulatory regimes are compared. The model shows that a policy disproportionately penalizing large firms can reduce output by nearly one-half, compared with an alternative policy regime in which all firms face the same taxes and regulatory costs.
QCD at High Temperature : Results from Lattice Simulations with an Imaginary mu
Creators: name: D'Elia, Massimo
name: Di Renzo, Francesco
name: Lombardo, Maria Paola
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We summarize our results on the phase diagram of QCD with emphasis on the high temperature regime. For $T \ge 1.5 T_c$ the results are compatible with a free field behavior, while for $T \simeq 1.1 T_c$ this is not the case, clearly exposing the strongly interacting nature of QCD in this region
description: 7 pages, 2 figures; To appear in the proceedings of QCD@Work 2005,International Workshop on Quantum Chromodynamics, Conversano, Bari, Italy, 16-20 Jun 2005
Nonlinearity accelerates the thermalization of the quartic FPUT model with stochastic baths
Creators: name: Schmid, Harald
name: Succi, Sauro
name: Ruffo, Stefano
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate the equilibration process of the strongly coupled quartic Fermi-Pasta-Ulam-Tsingou (FPUT) model by adding Langevin baths to the ends of the chain. The time evolution of the system is investigated by means of extensive numerical simulations and shown to match the results expected from equilibrium statistical mechanics in the time-asymptotic limit. Upon increasing the nonlinear coupling, the thermalization of the energy spectrum displays an increasing asymmetry in favour of small-scale, high-frequency modes, which relax significantly faster than the large-scale, low-frequency ones. The global equilibration time is found to scale linearly with system size and shown to exhibit a power-law decay with the strength of the nonlinearity and temperature. Nonlinear interaction adds to energy distribution among modes, thus speeding up the thermalization process.
Producer Behaviour Under Strict Rationing and Quai-Fixed Factors
Creators: name: Guyomard, Herve
name: Mahe, Louis Adrien Pascal
name: Guyomard, Herve
name: Mahe, Louis Adrien Pascal
Publisher: name: Unknown
Year: 1993
Subjects: Production Economics

description: The paper examines the effect of rationing outputs and inputs on producer behaviour. Full representation of the modified supply-demand system after rationing, including shadow prices for the constrained netputs, is derived from the unrestricted profit function before rationing, and vice-versa. Attention is focused on cross-price effects which have been less explored than own-price effects which obey to the Le Chatelier principle. The theoretical framework is applied to the EC agricultural sector in order to analyse the effects of output and input rationing on the production structure of the EC agricultural sector, with emphasis on the impact of the milk quota constraint on unrestricted output supplies and input demands.
Redeeming flesh : portrayals of women and sexuality in the work of four contemporary Catholic novelists
Creators: name: Baldwin, Ruth Margaret Anne
Publisher: name: University of British Columbia
Year: 2009

description: The last half of the twentieth century has seen a rapid increase in the process of secularization in both Britain and America, and this trend is nowhere more clearly evident than in the widespread relaxation of sexual mores. Within the Catholic Church a tension has arisen between liberal Catholics who argue for the right of Catholics to act according to the dictates of individual conscience, and traditionalists who champion the absolute moral authority of the Church. Liberal Catholics emphasize the Thomist view in which the flesh and its desires are seen as part of God's creation and, therefore, intrinsically good, while conservative Catholics lean toward an Augustinian/Jansenist view which equates sexual desire with the fallen nature of humankind. There has also been a great deal of unrest among Catholic women regarding continuing misogynistic tendencies within the male-dominated Church. This study focuses upon portrayals of women and sexuality in selected novels by four representative contemporary Catholic novelists, David Lodge, Mary Gordon, Piers Paul Read, and Anne Redmon. In their fiction, these writers pursue moral questions related to sexuality which preoccupy contemporary Catholics, reflecting in their work the empirical struggle of Catholics to reconcile Church law with their individual needs and desires. In their ratio to each other, these novelists represent in microcosm the spectrum of opinion among lay Catholics regarding sexual morality. Liberals David Lodge and Mary Gordon affirm in their fiction the goodness of the body and its desires, while Piers Paul Read argues for the orthodox view that the flesh must be rigidly controlled in the interests of spiritual health. Anne Redmon explores issues of women and sexuality without entering the debate between liberal and conservative Catholics. As this study makes clear, the contemporary Catholic novel provides an experientially based context for moral reflection on sexual behaviour parallel to and often in tension with the traditional teaching of the Church. The recent Catholic novel has also provided an important site for the exploration of women's sexual needs, desires, and moral thinking against the background of an all-male hierarchical Church, which has largely been silent in this area.
Some remarks on the angular momenta of galaxies, their clusters and superclusters
Creators: name: Godlowski, Wlodzimierz
name: Szydlowski, Marek
name: Flin, Piotr
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We discuss the relation between angular momenta and masses of galaxy structures base on the Li model of the universe with global rotation. In our previous paper (Godłowski et al 2002) it was shown that the model predicts the presence of a minimum in this relation. In the present paper we discuss observational evidence allowing us to verify this relation. We find null angular momentum J=0 for the masses corresponding to mass of galaxy grups and non-vanishing angular momenta for other galactic structures. We check these theoretical predictions analysing Tully's galaxy grups. The existing data comparing alignment in different galactic structure are consistent with obtained theoretical relation $J(M)$ if we interpret the groving alignment as the galactic increasing angular momenta in the galactic structure.
description: 20 pages 1 figure. GRG accepted
Gravitational Constraints on a Lightlike boundary
Creators: name: Canepa, Giovanni
name: Cattaneo, Alberto S.
name: Tecchiolli, Manuel
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mathematical Physics (math-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences
subject: 83C47, 83C05

description: We analyse the boundary structure of General Relativity in the coframe formalism in the case of a lightlike boundary, i.e., when the restriction of the induced Lorentzian metric to the boundary is degenerate. We describe the associated reduced phase space in terms of constraints on the symplectic space of boundary fields. We explicitly compute the Poisson brackets of the constraints and identify the first- and second-class ones. In particular, in the 3+1 dimensional case, we show that the reduced phase space has two local degrees of freedom, instead of the usual four in the non-degenerate case.
description: 42 pages, accepted for publication in Ann. Henri Poincar\'e. Improved version, added section about independence of the structure from the choices
Arundhati Roy führt Solidaritätsmarsch ins Narmada-Tal
Creators: name: Hörig, Rainer
Publisher: name: Südasien
Year: 2024

description: Südasien, Bd. 19 Nr. 5 (1999): Armutsbekämpfung und Weltfrieden: Die Südasienpolitik Deutschlands und der EU
One-loop Kubo estimations of the shear and bulk viscous coefficients for hot and magnetized Bosonic and Fermionic systems
Creators: name: Ghosh, Snigdha
name: Ghosh, Sabyasachi
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The expressions of the shear viscosity and the bulk viscosity components in the presence of an arbitrary external magnetic field for a system of hot charged scalar Bosons (spin-0) as well as for a system of hot charged Dirac Fermions (spin-$\frac{1}{2}$) have been derived by employing the one-loop Kubo Formalism. This is done by explicitly evaluating the thermo-magnetic spectral functions of the energy momentum tensors using the real time formalism of finite temperature field theory and the Schwinger proper time formalism. In the present work, a rich quantum field theoretical structure in the expressions of the viscous coefficients in non-zero magnetic field are found, which are different from their respective expressions obtained earlier via kinetic theory based calculations; though, in absence of magnetic field, the one-loop Kubo and the kinetic theory based expressions for the viscosities are known to be identical. We have identified that Kubo and kinetic theory based results of viscosity components follow similar kind of temperature and magnetic field dependency. The relaxation time and the synchrotron frequency in the kinetic theory formalism are realized to be connected respectively with the thermal width of propagator and the transitions among the Landau levels of the charged particles in the Kubo formalism. We believe that, the connection of latter quantities are quite new and probably the present work is the first time addressing this interpretation along with the new expressions of viscosity components, not seen in existing works.
description: Version published in Physical Review D
Structural Parameters of Thin and Thick Disks in Edge-On Disk Galaxies
Creators: name: Yoachim, Peter
name: Dalcanton, Julianne J.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We analyze the global structure of 34 late-type, edge-on, undisturbed, disk galaxies spanning a wide range of mass. We measure structural parameters for the galaxies using two-dimensional least-squares fitting to our $R$-band photometry. The fits require both a thick and a thin disk to adequately fit the data. The thick disks have larger scale heights and longer scale lengths than the embedded thin disks, by factors of ~2 and ~1.25, respectively. The observed structural parameters agree well with the properties of thick and thin disks derived from star counts in the Milky Way and from resolved stellar populations in nearby galaxies. We find that massive galaxies' luminosities are dominated by the thin disk. However, in low mass galaxies (Vc < 120 km/s), thick disk stars contribute nearly half of the luminosity and dominate the stellar mass. Thus, although low mass dwarf galaxies appear blue, the majority of their stars are probably quite old. Our data are most easily explained by a formation scenario where the thick disk is assembled through direct accretion of stellar material from merging satellites while the thin disk is formed from accreted gas. The baryonic fraction in the thin disk therefore constrains the gas-richness of the merging pre-galactic fragments. If we include the mass in HI as part of the thin disk, the thick disk contains <10% of the baryons in high mass galaxies, and ~25-30% of the baryons in low-mass galaxies. We discuss how our trends can be explained by supernova-driven outflow at early times as well as the possibilities for predicting abundance trends in thick disks, and for removing discrepancies between semi-analytic galaxy formation models and the observed colors of low mass galaxies. (abstract abridged)
description: 25 pages, 24 figures, accepted for publication in AJ
The GATT Negotiations and US/EC Agricultural Policies Solutions to Noncooperative Games
Creators: name: Johnson, Martin
name: Roe, Terry L.
name: Mahe, Louis Adrien Pascal
name: Johnson, Martin
name: Roe, Terry L.
name: Mahe, Louis Adrien Pascal
Publisher: name: Unknown
Year: 1989
Subjects: Agricultural and Food Policy
International Relations/Trade

description: Countries cooperate in negotiating treaties. However, treaty compliance is noncooperative; signatories comply with treaties only if compliance leaves them better off than noncompliance. US and EC agricultural policies of 1986 are modeled through a noncooperative game. Bilateral treaties, formalizations of Nash Equilibria, are presented which improve US and EC welfare.
Magnetic Compton profiles of Ni beyond the one-particle picture: numerically exact and perturbative solvers of dynamical mean-field theory
Creators: name: James, A. D. N.
name: Sekania, M.
name: Dugdale, S. B.
name: Chioncel, L.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We calculated the magnetic Compton profiles (MCPs) of Ni using density functional theory supplemented by electronic correlations treated within dynamical mean-field theory (DMFT). We present comparisons between the theoretical and experimental MCPs. The theoretical MCPs were calculated using the KKR method with the perturbative spin-polarized T-matrix fluctuation exchange approximation DMFT solver, as well as with the full potential linear augmented planewave method with the numerically exact continuous-time quantum Monte Carlo DMFT solver. We show that the total magnetic moment decreases with the intra-atomic Coulomb repulsion $U$, which is also reflected in the corresponding MCPs. The total magnetic moment obtained in experimental measurements can be reproduced by intermediate values of $U$. The spectral function reveals that the minority X$_2$ Fermi surface pocket shrinks and gets shallower with respect to the density functional theory calculations.
A Nested Sampling Algorithm for Cosmological Model Selection
Creators: name: Mukherjee, Pia
name: Parkinson, David
name: Liddle, Andrew R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The abundance of new cosmological data becoming available means that a wider range of cosmological models are testable than ever before. However, an important distinction must be made between parameter fitting and model selection. While parameter fitting simply determines how well a model fits the data, model selection statistics, such as the Bayesian Evidence, are now necessary to choose between these different models, and in particular to assess the need for new parameters. We implement a new evidence algorithm known as nested sampling, which combines accuracy, generality of application and computational feasibility, and apply it to some cosmological datasets and models. We find that a five-parameter model with Harrison-Zel'dovich initial spectrum is currently preferred.
description: 4 pages, 3 figures. Minor updates to match version accepted by Astrophys J Letters
On the usefulness of government spending in the EU area
Creators: name: Marattin, Luigi
name: Salotti, Simone
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: SECS-P/01 Economia politica

description: We investigate the effects of fiscal policy on private consumption and investment in the European Union. A certain consensus has aroused that fiscal impulses have expansionary Keynesian effects on the economic activity. However, the existing empirical literature has concentrated on few countries, mostly outside the EU. We check the validity of this result for the EU area, by using annual data and a panel vector auto-regression approach (PVAR). Our results show that increases in public spending lead to positive and significant effects on private consumption and private investment. According to our baseline estimate, a 1% increase in public spending produces a 0.36% on impact rise in private consumption, and a 0.79% impact rise in private investment. The effects are substantial, and die out slowly (faster in the case of private consumption). A further disaggregation between wage and non-wage components reveals different effects. As for the impact on private consumption, our results show that public salaries have a relatively stronger stimulating role, a result which is probably due to the importance of the public sector especially in continental Europe. On the other hand, the positive impact on private investment is mainly due to the non-wage component of government consumption.
Materials Science: Data to Drive Autonomy and Digital Twins
Creators: name: Elbert, David
Publisher: name: DataCite
Year: 2024
Subjects: Persistent Identifiers
Metadata
Instruments
Life Sciences
Astronomy
Metadata Game Changers

description: DataCite, in partnership with Metadata Game Changers, is excited to announce two community dialogue sessions designed to engage the broader Life Sciences and Astronomy communities in co-developing metadata enhancements supporting the development and use of persistent identifiers (PIDs) for instruments and projects. We would like to invite both metadata creators and users to join us and take an active role in advancing infrastructure solutions to identify, describe, discover, and track the impact of instruments and projects across domain communities.

The Persistent Identifiers for Instruments Community Dialogue will build on the work of the Persistent Identification of Instruments (PIDInst) group and the FAIR Facilities and Instruments Research Coordination Network.

Topics will include:

Ownership & provenance

Series & versioning

Replicability & reuse

Discoverability

Impact measurement

These dialogues represent the first phase of a larger project recently launched by DataCite. Generously funded by the Richard Lounsbery Foundation, this project aims to address present challenges in data accessibility, transparency, and reproducibility across the Life Science and Astronomy communities by fostering collaboration and developing transformative solutions. Insights, feedback, and proposed metadata enhancements gathered during these dialogues will directly inform subsequent prototype developments designed by DataCite.

Speaker: David Elbert (Johns Hopkins University)

A recording of the presentation can be found here: https://www.youtube.com/watch?v=fjR5VaBMIqc&t=1550s
On non-canonical degrees of freedom
Creators: name: Quinn, Eoin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Non-canonical degrees of freedom provide one of the most promising routes towards characterising a range of important phenomena in condensed matter physics. Potential candidates include the pseudogap regime of the cuprates, heavy-fermion behaviour, and also indeed magnetically ordered systems. Nevertheless it remains an open question whether non-canonical algebras can in fact provide legitimate quantum degrees of freedom. In this manuscript we survey progress made on this topic, complementing distinct approaches so as to obtain a unified description. In particular we obtain a novel closed-form expression for a self-energy-like object for non-canonical degrees of freedom. We further make a resummation of density correlations to obtain analogues of the RPA and GW approximations commonly employed for canonical degrees of freedom. We discuss difficulties related to generating higher-order approximations which are consistent with conservation laws, which represents an outstanding issue. We also discuss how the interplay between canonical and non-canonical degrees of freedom offers a useful paradigm for organising the phase diagram of correlated electronic behaviour.
description: Published version
On Endogenous Growth: The Implications of Environmental Externalities
Creators: name: Elbasha, Elamin H.
name: Roe, Terry L.
name: Elbasha, Elamin H.
name: Roe, Terry L.
Publisher: name: Unknown
Year: 1995
Subjects: Environmental Economics and Policy

description: This paper uses an endogenous growth model to examine the interaction between trade, economic growth, and the environment. We find that whether trade enhances or retards growth depends on the relation between factor intensities of exportable, importable, and R&D and the relative abundance of the factor R&D uses more intensively. Depending on the intertemporal elasticity of substitution, the long-run rate of economic growth changes with environmental externalities. Concerns about the environment can explain a significant part of cross-country difference in growth rates. For the empirically reported range of the elasticity of intertemporal substitution, countries which care more about the environment grow faster. The effects of trade on the environment and welfare depend on the elasticities of supply for the two traded goods, the terms of trade effect on growth, and pollution intensities. The decentralized and Pareto optimal growth rates are, in general, different. The market growth rate is bigger than the optimal rate the larger the degree of monopoly power in the innovation sector and the stronger the effects of environmental externalities. The policy implications of this divergence are discussed. We also consider numerical exercises to broaden the insights from the analytical results and allow for incorporating pollution abatement
High-energy Cu spin excitations in PrBa2Cu3O6+x
Creators: name: Boothroyd, A. T.
name: Andersen, N. H.
name: Larsen, B. H.
name: Zhokhov, A. A.
name: Frost, C. D.
name: Adroja, D. T.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: This paper describes high-energy neutron inelastic scattering measurements of propagating magnetic excitations in PrBa2Cu3O6+x (x approx 0.2 and 0.93). The measurements probe the acoustic and optic modes of the antiferromagnetically-ordered copper--oxygen bilayers in the energy range 50-150 meV. The observed magnon dispersion can be described satisfactorily in this energy range by a spin wave model including intra- and inter-layer nearest-neighbour exchange constants J_parallel and J_perp. We find J_parallel = 127 +/- 10 meV and J_perp = 5.5 +/- 0.9 meV. The value of J_parallel is virtually the same as that found in YBa2Cu3O6.2, but J_perp is a factor of two smaller. To within experimental error the values of J_parallel and J_perp for PrBa2Cu3O6+x do not vary with oxygen doping.
description: 6 pages, 5 figures. To be published in Phys. Rev. B
Putting a spin on metamaterials: Mechanical incompatibility as magnetic frustration
Creators: name: Pisanty, Ben
name: Oguz, Erdal C.
name: Nisoli, Cristiano
name: Shokef, Yair
Publisher: name: arXiv
Year: 2020
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Mechanical metamaterials present a promising platform for seemingly impossible mechanics. They often require incompatibility of their elementary building blocks, yet a comprehensive understanding of its role remains elusive. Relying on an analogy to ferromagnetic and antiferromagnetic binary spin interactions, we present a universal approach to identify and analyze topological mechanical defects for arbitrary building blocks. We underline differences between two- and three-dimensional metamaterials, and show how topological defects can steer stresses and strains in a controlled and non-trivial manner and can inspire the design of materials with hitherto unknown complex mechanical response.
Relationship-Specificity, Spatial Clustering and Production to Order Choice
Creators: name: Casaburi, Lorenzo
name: Minerva, G. Alfredo
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: SECS-P/02 Politica economica

description: We study the determinants of the firm-level choice to produce following an order placed by a downstream firm (production to order) or to produce in advance. We rationalize this choice through a simple theoretical model and apply it to a firm-level empirical analysis. Relying on a large dataset of Italian manufacturing firms, we show that two main variables affect this choice: the extent of spatial clustering of the industry, and the degree of product complexity and relationship-specificity of the goods that are traded. The sign of the impact of clustering on the choice of producing to order crucially depends on product complexity. If product complexity is high, production to order prevails when firms are clustered together. On the contrary, clustering is associated to production in advance for sectors where goods are standardized.
Microeconometric Models of Consumer and Producer Demand with Limited Dependent Variables
Creators: name: Lee, Lung-Fei
name: Pitt, Mark M.
name: Lee, Lung-Fei
name: Pitt, Mark M.
Publisher: name: Unknown
Year: 1984
Subjects: Demand and Price Analysis

description: The specification and estimation of models of consumer and producer demand with kink points are considered. The presence of kink points divides the demand or production schedule into different regimes. Our approach utilizes the concept of virtual prices. The virtual prices transform binding quantities into nonbinding ones and provide a rigorous justification for structural change in the observed demand functions across regimes. The comparison of virtual prices with market prices determines regime occurences. An application to energy demand in Indonesian manufacturing firms based on the translog cost function is provided.
Distortionary tax instruments and implementable monetary policy
Creators: name: Marattin, Luigi
name: Marzo, Massimiliano
name: Zagaglia, Paolo
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: SECS-P/01 Economia politica

description: We introduce distortionary taxes on consumption, labor and capital income into a New Keynesian model with Calvo pricing and nominal bonds. We study the relation between tax instruments and optimal monetary policy by computing simple rules for monetary and fiscal policy when one tax instrument at a time varies, while the other two are fixed at their steady-state level. The optimal rules maximize the second-order approximation to intertemporal utility. Three results emerge: (a) when prices are sticky, perfect inflation stabilization is optimal independently from the tax instrument adopted; (b) the optimal degree of responsiveness of monetary policy to output varies depending on which tax instrument induces fluctuations in the average tax rate; (c) when prices are flexible, fiscal rules that prescribe unexpected variations in the price level to support debt changes are always welfare-maximizing.
A New Thermodynamics from Nuclei to Stars III
Creators: name: Gross, D. H. E.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Astrophysics (astro-ph)
subject: Nuclear Theory (nucl-th)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: FOS: Physical sciences

description: Equilibrium statistics of Hamiltonian systems is correctly described by the microcanonical ensemble. Classically this is the manifold of all points in the $N-$body phase space with the given total energy. Due to Boltzmann's principle, $e^S=tr(δ(E-H))$, its geometrical size is related to the entropy $S(E,N,...)$. This definition does not invoke any information theory, no thermodynamic limit, no extensivity, and no homogeneity assumption, as are needed in conventional (canonical) thermo-statistics. Therefore, it describes the equilibrium statistics of extensive as well of non-extensive systems. Due to this fact it is the {\em fundamental} definition of any classical equilibrium statistics. It can address nuclei and astrophysical objects as well. All kind of phase transitions can be distinguished sharply and uniquely for even small systems. It is further shown that the second law is a natural consequence of the statistical nature of thermodynamics which describes all systems with the same -- redundant -- set of few control parameters simultaneously. It has nothing to do with the thermodynamic limit. It even works in systems which are by far {\em larger} than any thermodynamic "limit".
description: 22 pages, 11 figures, treatment of the second law included