cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Optimal control of the COVID-19 pandemic: controlled sanitary deconfinement in Portugal
Creators: name: Silva, Cristiana J.
name: Cruz, Carla
name: Torres, Delfim F. M.
name: Munuzuri, Alberto P.
name: Carballosa, Alejandro
name: Area, Ivan
name: Nieto, Juan J.
name: Fonseca-Pinto, Rui
name: da Fonseca, Rui Passadouro
name: Santos, Estevao Soares dos
name: Abreu, Wilson
name: Mira, Jorge
Publisher: name: arXiv
Year: 2020
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Optimization and Control (math.OC)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: FOS: Biological sciences

description: The COVID-19 pandemic has forced policy makers to decree urgent confinements to stop a rapid and massive contagion. However, after that stage, societies are being forced to find an equilibrium between the need to reduce contagion rates and the need to reopen their economies. The experience hitherto lived has provided data on the evolution of the pandemic, in particular the population dynamics as a result of the public health measures enacted. This allows the formulation of forecasting mathematical models to anticipate the consequences of political decisions. Here we propose a model to do so and apply it to the case of Portugal. With a mathematical deterministic model, described by a system of ordinary differential equations, we fit the real evolution of COVID-19 in this country. After identification of the population readiness to follow social restrictions, by analyzing the social media, we incorporate this effect in a version of the model that allow us to check different scenarios. This is realized by considering a Monte Carlo discrete version of the previous model coupled via a complex network. Then, we apply optimal control theory to maximize the number of people returning to "normal life" and minimizing the number of active infected individuals with minimal economical costs while warranting a low level of hospitalizations. This work allows testing various scenarios of pandemic management (closure of sectors of the economy, partial/total compliance with protection measures by citizens, number of beds in intensive care units, etc.), ensuring the responsiveness of the health system, thus being a public health decision support tool.
description: Paper whose final and definite form is published Open Access by 'Scientific Reports', ISSN 2045-2322, Springer Nature. Submitted 01/Sept/2020; Revised 16/Dec/2020; Accepted 27/Jan/2021; Published by [www.nature.com/scientificreports], see [https://doi.org/10.1038/s41598-021-83075-6]
Do Eating Patterns Follow a Cohort or Change Over a Lifetime? Answers Emerging from the Literature
Creators: name: Wendt, Minh
name: Kinsey, Jean D.
name: Wendt, Minh
name: Kinsey, Jean D.
Publisher: name: Unknown
Year: 2007
Subjects: subject: Food Consumption/Nutrition/Food Safety
subject: Food consumption
subject: cohort
subject: age effect

description: With the rapidly increasing American elderly population, food companies, healthcare workers, and policy makers alike are asking whether the dietary habits and food consumption patterns of this growing segment of the U.S. population will follow those of current and past elderly people or whether their cohort will eat like they did when they were younger. The purpose of this report is to review what is known about changes in nutritional intake and food consumption patterns that are associated with cohorts (generational) and with the aging process in the U.S. population. Recent literature on cohort and aging effects related to food consumption indicates that the aging effect is greater than the cohort effect. That is, diets change as people age, due to factors such as food availability, new information, new cumulative experiences, and physiological changes as bodies mature. Cohort effect is more likely due to changes in income, i.e., each succeeding cohort realizing higher real per capita income. Variation in findings is likely due to different data sources and analytic methods. Information on data sources and common databases used in these types of studies are also reviewed.
Efficient solvability of Hamiltonians and limits on the power of some quantum computational models
Creators: name: Somma, Rolando
name: Barnum, Howard
name: Ortiz, Gerardo
name: Knill, Emanuel
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We consider quantum computational models defined via a Lie-algebraic theory. In these models, specified initial states are acted on by Lie-algebraic quantum gates and the expectation values of Lie algebra elements are measured at the end. We show that these models can be efficiently simulated on a classical computer in time polynomial in the dimension of the algebra, regardless of the dimension of the Hilbert space where the algebra acts. Similar results hold for the computation of the expectation value of operators implemented by a gate-sequence. We introduce a Lie-algebraic notion of generalized mean-field Hamiltonians and show that they are efficiently ("exactly") solvable by means of a Jacobi-like diagonalization method. Our results generalize earlier ones on fermionic linear optics computation and provide insight into the source of the power of the conventional model of quantum computation.
description: 6 pages; no figures
Architectural History of the Bangladesh Region as Background of Louis Kahn's Dacca Project
Creators: name: Ali, Meer Mobashsher
Publisher: name: The University of Texas at Austin
Year: 0
Subjects: Kahn, Louis I., 1901-1974
Bangladesh
India
Burma
Dhaka (Bangladesh)
stupas
Tagore, Rabîndranâth, 1861-1941
Shankar, Ravi, 1920-2012.
Rāmakrishna 1836-1886
stepped pyramids
Geometry in architecture
terra-cotta
Panam Nagar
Buddhism
Hinduism
mandala
Architectural practice
motifs
columns
Islamic domes
ruins
Brickwork
Arches
Imperialism
Architecture, Mogul Empire
Indo-Islamic architecture
Great Britain
Pakistan
self
culture
cultural heritage
regionalism
Architectural design
Le Corbusier, 1887-1965
Light in architecture
Scully, Vincent, Jr., 1920-
Harmony (Aesthetics)
secularism
religious architecture
Democracy and architecture

description: Architectural projects and/or sites mentioned: Somapura Mahavihara (8th century AD) (Paharpur, Bangladesh) ; Jatiya Sangsad Bhaban (Dhaka) (Louis Kahn, 12th century ) (Dhaka, Bangladesh) ; Angkor Wat (deserted settlement) (Suryavarman II , Jăyvarmăn VII, 1985-87) (Krong Siem Reap, Cambodia) ; Borobudur (Gunadharma, 9th century) (Central Java, Indonesia) ; Eklakhi Mausoleum (1425) (Pandua, West Bengal, India) ; Shait Gambuj Mosque (Khan Jahan Ali, 15th century) (Bagerhat, Bangladesh) ; Taj Mahal (Ustad Ahmad Lahauri, 1632-53) (Agra, India) ; Kamalapur Railway Station (Robert Boughey, 1961-64) (Dhaka, Bangladesh)
description: Audio files are EID restricted. Individuals without an EID should send an email request to apl-aaa@lib.utexas.edu.
From colored gravity to electromagnetism
Creators: name: Monjo, Robert
name: Rodríguez-Abella, Álvaro
name: Campoamor-Stursberg, Rutwig
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences
subject: 31E05, 81V10, 81V17, 81V22, 83C22, 83C50

description: The gauge formalism in \textit{telepalallel gravity} provides an interesting viewpoint to describe interactions according to an anholonomic observer's tetrad basis. Without going into assessing the complete viability of quantization in an early stage, this paper explores classical gravity within the framework of a classical-to-quantum bridge between the SU$(1, 3)$ Yang--Mills gauge formalism and the gauge-like treatment of teleparallel gravity. Specifically, the perturbed spacetime algebra with Weitzenböck connection can be assimilated to a local complexification based on the SU$(1,3)$ Yang--Mills theory, what we call hypercolor or, simply, color. The formulation of the hypercolor dynamics is build by a translational gauge, as in the teleparallel gravities. In particular, this work analyses small perturbations of a metric decomposition related to the Wilson line and the Kaluza--Klein metric, but obtaining electrodynamics in four dimensions. The spacetime coordinates are now matrices that represent elements of the $\mathfrak{su}(1,3)$ algebra. To make compatible the formulation of a colored gravity with the Lorentz force and the Maxwell equations, it is enough to define every energy potential origin as 0 in the event horizon instead of the classic zero potential at infinity. Under the colored gravity framework, standard electromagnetism can be obtained as a particular abelian case.
description: 44 pages, no figures
Frustration induced incommensurate solids in the extended Bose-Hubbard model
Creators: name: Ng, Kwai-Kong
name: Yang, Min-Fong
Publisher: name: arXiv
Year: 2020
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We study the extended Bose-Hubbard model with nearest-neighbor and next-nearest-neighbor $(V, V')$ repulsive interactions on a square lattice by using the quantum Monte Carlo method. Unlike the case of strong $V'$ where the ground states can be striped solids or striped supersolids, we focus on weak $V' < V/2$ and small hoppings and find that, in the thermodynamic limit, incommensurate solids of fractional densities varying from 1/4 to 1/2 can be stabilized. We also show that the incommensurate solids, which are characterized by a continuous set of wave vectors changing from $(π,π/2)$ (or $(π/2,π)$) to $(π,π)$, can be understood by a mechanism of domain wall formation. The related ground-state phase diagram and thermal phase transitions are also discussed.
description: 7 pages, 7 figures
Edward Allen Construction Lecture
Creators: name: Allen, Edward
Publisher: name: The University of Texas at Austin
Year: 1987
Subjects: Allen, Edward, 1938-
Massachusetts institute of technology
Building materials
Moore, Charles Willard, 1925-1993
University of California, Berkeley
bricks
Brickwork
corbels
mortar
Masonry
Vaults (Architecture)
Tensile architecture
Decoration and ornament, Architectural
Botta, Mario, 1943-
Boston (Mass.)
Back Bay (Boston, Mass.)
keystones
Jefferson, Thomas, 1743-1826
University of Virginia
minarets
Kahn, Louis I., 1901-1974
buttresses
Stacks (Naval architecture)
Terra-cotta
herringbone
Arches
barrel vaults
groined vaults
parabola
Khalili, Nader, 1936-2008
domes
earthen architecture
San Antonio (Tex.)
Ford, O'Neil, 1905-1982
pitched-brick vaults
Gaudí, Antoni, 1852-1926
Barcelona (Spain)
columns
ribbed vaults
Organic architecture
Meier, Richard, 1934-
Bridges--design and construction
Architecture--Aesthetics
Architectural design

description: Architectural projects and/or sites mentioned: Great Mosque of Samarra (851 CE) (Samarra, Iraq) ; Cathédrale Sainte-Cécile d'Albi (1282 - 1480) (Albi, France) ; V.C. Morris Gift Shop (Frank Lloyd Wright , 1948) (San Francisco, California) ; La Pedrera (Antoni Gaudí, 1906 - 1914) (Barcelona, Spain) ; Church of Colònia Güell (Antoni Gaudí, 1898 - 1914) (Santa Coloma de Cervelló, Spain)
description: Audio files are EID restricted. Individuals without an EID should send an email request to apl-aaa@lib.utexas.edu.
AJAE Appendix: Challenges to the Development of a Dedicated Energy Crop
Creators: name: Epplin, Francis M.
name: Clark, Christopher D.
name: Roberts, Roland K.
name: Hwang, Seonghuyk
name: Epplin, Francis M.
name: Clark, Christopher D.
name: Roberts, Roland K.
name: Hwang, Seonghuyk
Publisher: name: Unknown
Year: 2007
Subjects: Crop Production/Industries
Research and Development/Tech Change/Emerging Technologies

description: The material contained herein is supplementary to the article named in the title and published in the American Journal of Agricultural Economics, Volume 89, Number 5, December 2007.
Dyson's Equations for Quantum Gravity in the Hartree-Fock Approximation
Creators: name: Hamber, Herbert W.
name: Yu, Lu Heng Sunny
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Unlike scalar and gauge field theories in four dimensions, gravity is not perturbatively renormalizable and as a result perturbation theory is badly divergent. Often the method of choice for investigating nonperturbative effects has been the lattice formulation, and in the case of gravity the Regge-Wheeler lattice path integral lends itself well for that purpose. Nevertheless, lattice methods ultimately rely on extensive numerical calculations, leaving a desire for alternate calculations that can be done analytically. In this work we outline the Hartree-Fock approximation to quantum gravity, along lines which are analogous to what is done for scalar fields and gauge theories. The starting point is Dyson's equations, a closed set of integral equations which relate various physical amplitudes involving graviton propagators, vertex functions and proper self-energies. Such equations are in general difficult to solve, and as a result not very useful in practice, but nevertheless provide a basis for subsequent approximations. This is where the Hartree-Fock approximation comes in, whereby lowest order diagrams get partially dressed by the use of fully interacting Green's function and self-energies, which then lead to a set of self-consistent integral equations. Specifically, for quantum gravity one finds a nontrivial ultraviolet fixed point in Newton's constant G for spacetime dimensions greater than two, and nontrivial scaling dimensions between d=2 and d=4, above which one obtains Gaussian exponents. In addition, the Hartree-Fock approximation gives an explicit analytic expression for the renormalization group running of Newton's constant, suggesting gravitational antiscreening with Newton's G slowly increasing on cosmological scales.
description: 71 pages, 21 figures. More typos fixed, references added
Phenomenology of Higgsless Models at the LHC and the ILC
Creators: name: Birkedal, Andreas
name: Matchev, Konstantin T.
name: Perelstein, Maxim
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We investigate the signatures of the recently proposed Higgsless models at future colliders. We focus on tests of the mechanism of partial unitarity restoration in the longitudinal vector boson scattering, which do not depend on any Higgsless model-building details. We study the LHC discovery reach for charged massive vector boson resonances and show that all of the preferred parameter space will be probed with $100 {\rm fb}^{-1}$ of LHC data. We also discuss the prospects for experimental verification of the Higgsless nature of the model at the LHC. In addition, in this talk we present new results relevant for the discovery potential of Higgsless models at the International Linear Collider (ILC).
description: 6 pages, 6 figures, to appear in the proceedings of the 2005 International Linear Collider Workshop, Stanford, USA
Non-parametric Dark Energy Degeneracies
Creators: name: Hlozek, Renée
name: Cortês, Marina
name: Clarkson, Chris
name: Bassett, Bruce
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study the degeneracies between dark energy dynamics, dark matter and curvature using a non-parametric and non-perturbative approach. This allows us to examine the knock-on bias induced in the reconstructed dark energy equation of state, w(z), when there is a bias in the cosmic curvature or dark matter content, without relying on any specific parameterisation of w. Even assuming perfect Hubble, distance and volume measurements, we show that for z > 1, the bias in w(z) is up to two orders of magnitude larger than the corresponding errors in Omega_k or Omega_m. This highlights the importance of obtaining unbiased estimators of all cosmic parameters in the hunt for dark energy dynamics.
description: 10 pages, 8 figures. Invited Review for special issue of General Relativity and Gravitation issue on Dark Energy, eds. G. F.R Ellis et al
Dualistic Structures on Twisted Product Manifolds
Creators: name: Diallo, Abdoul Salam
name: Todjihounde, Leonard
Publisher: name: arXiv
Year: 2014
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 2010: 53A15, 53B05, 53B15, 53B20

description: In this paper, we show that the projection of a dualistic structure defined on a twisted product manifold induces dualistic structures on the base and the fiber manifolds, and conversely. Then under some conditions on the Ricci curvature and the Weyl conformal tensor we characterize dually flat structures on twisted product manifolds.
description: 12 pages
Effects of Parental Diet on Nutritional Composition of Yolk and Metabolic Programming in Southern Flounder
Creators: name: Li, Yu Ting
Publisher: name: The University of Texas at Austin
Year: 2023
Subjects: fish physiology
lipid metabolism
nutritional programming
metabolic programming
southern flounder
fatty acid
larval fish
maternal nutrition

description: Fatty acids play a critical role in cellular functions and are vital to the growth and development of fish during early stages of life. The nutrients available to fish embryos and early larvae are dependent on recent maternal diet in certain fish species, including Southern Flounder (Paralichthys lethostigma). Variations in maternal diet can result in subsequent changes to metabolic functioning of offspring, such as capacity for nutrient absorption, which is indicative of metabolic programming. The aim of this study was to (1) investigate the effects of the maternal diet on the fatty acid profiles of eggs, and (2) determine whether Southern Flounder exhibit metabolic programming in the form of measured differences in larval fatty acid composition between spawns from two maternal diet treatment groups (shrimp or sardine). Results demonstrated direct diet-egg relationships for 11 fatty acids, with the majority of these fatty acids being higher in the shrimp diet and corresponding eggs. Analyses of larval fatty acid composition, however, did not reveal significant differences in any of the 27 fatty acids measured for any of the three larval stages sampled. Therefore, there was no evidence of metabolic programming in Southern Flounder based on comparisons of larval fatty acid composition among parental diet treatments. This contrasts with prior studies that provided evidence for metabolic programming in marine teleosts.
Total helicity of electromagnetic fields and matter
Creators: name: Fernandez-Corbaton, Ivan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The electromagnetic helicity of the free electromagnetic field and the static magnetic helicity are shown to be two different embodiments of the same physical quantity, the total helicity. The total helicity is the sum of two terms: a term that measures the difference between the number of left-handed and right-handed photons of the free field, and another term that measures the screwiness of the static magnetization density in matter. Each term is the manifestation of the total helicity in different frequency regimes: $ω$ > 0 and $ω$ = 0, respectively. This unification establishes the theoretical basis for studying the conversion between the two embodiments of total helicity upon light-matter interaction.
Invisible neutrino decay in precision cosmology
Creators: name: Barenboim, Gabriela
name: Chen, Joe Zhiyu
name: Hannestad, Steen
name: Oldengott, Isabel M.
name: Tram, Thomas
name: Wong, Yvonne Y. Y.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We revisit the topic of invisible neutrino decay in the precision cosmological context, via a first-principles approach to understanding the cosmic microwave background and large-scale structure phenomenology of such a non-standard physics scenario. Assuming an effective Lagrangian in which a heavier standard-model neutrino $ν_H$ couples to a lighter one $ν_l$ and a massless scalar particle $ϕ$ via a Yukawa interaction, we derive from first principles the complete set of Boltzmann equations, at both the spatially homogeneous and the first-order inhomogeneous levels, for the phase space densities of $ν_H$, $ν_l$, and $ϕ$ in the presence of the relevant decay and inverse decay processes. With this set of equations in hand, we perform a critical survey of recent works on cosmological invisible neutrino decay in both limits of decay while $ν_H$ is ultra-relativistic and non-relativistic. Our two main findings are: (i) in the non-relativistic limit, the effective equations of motion used to describe perturbations in the neutrino--scalar system in the existing literature formally violate momentum conservation and gauge invariance, and (ii) in the ultra-relativistic limit, exponential damping of the anisotropic stress does not occur at the commonly-used rate $Γ_{\rm T} =(1/τ_0) (m_{νH}/E_{νH})^3$, but at a rate $\sim (1/τ_0) (m_{νH}/E_{νH})^5$. Both results are model-independent. The impact of the former finding on the cosmology of invisible neutrino decay is likely small. The latter, however, implies a significant revision of the cosmological limit on the neutrino lifetime $τ_0$ from $τ_0^{\rm old} \gtrsim 1.2 \times 10^9\, {\rm s}\, (m_{νH}/50\, {\rm meV})^3$ to $τ_0 \gtrsim (4 \times 10^5 \to 4 \times 10^6)\, {\rm s}\, (m_{νH}/50 \, {\rm meV})^5$.
description: 53 pages, 10 figures, v2 matches the accepted JCAP version
The possible orbital period of the nova V1493 Aquilae
Creators: name: Dobrotka, Andrej
name: Friedjung, Michael
name: Retter, Alon
name: Hric, Ladislav
name: Novak, Rudolf
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Period analysis of CCD photometry of V1493 Aql (Nova Aql 1999 no. 1) performed during 12 nights through I and R filters a few weeks after maximum is presented. The PDM method for period analysis (Stellingwerf 1978) is used. The photometric data is modulated with a period of 0.156 +- 0.001 d. Following the sinusoidal shape of the phased light curve, we interpret this periodicity as possibly orbital in nature which is consistent with a cataclysmic variable above the period gap.
description: 4 pages, 4 figures, accepted for publication in A&A
The interaction-sensitive states of a trapped two-component ideal Fermi gas and application to the virial expansion of the unitary Fermi gas
Creators: name: Endo, Shimpei
name: Castin, Yvan
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We consider a two-component ideal Fermi gas in an isotropic harmonic potential. Some eigenstates have a wavefunction that vanishes when two distinguishable fermions are at the same location, and would be unaffected by s-wave contact interactions between the two components. We determine the other, interaction-sensitive eigenstates, using a Faddeev ansatz. This problem is nontrivial, due to degeneracies and to the existence of unphysical Faddeev solutions. As an application we present a new conjecture for the fourth-order cluster or virial coefficient of the unitary Fermi gas, in good agreement with the numerical results of Blume and coworkers.
description: Updated augmented version in English (33 pages) and in French (35 pages)
AJAE Appendix: Agricultural Contracts: Data and Research Needs
Creators: name: Hueth, Brent
name: Ligon, Ethan
name: Dimitri, Carolyn
name: Hueth, Brent
name: Ligon, Ethan
name: Dimitri, Carolyn
Publisher: name: Unknown
Year: 2007
Subjects: Farm Management

description: The material herein contained is supplementary to the article name in the title and published in the American Journal of Agricultural Economics, Volume 89, Number 5, December 2007.
Stationarization and Multithermalization in spin glasses
Creators: name: Contucci, Pierluigi
name: Corberi, Federico
name: Kurchan, Jorge
name: Mingione, Emanuele
Publisher: name: arXiv
Year: 2020
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences
subject: 82B44

description: We develop further the study of a system in contact with a multibath having different temperatures at widely separated timescales. We consider those systems that do not thermalize in finite times when in contact with an ordinary bath but may do so in contact with a multibath. Thermodynamic integration is possible, thus allowing one to recover the stationary distribution on the basis of measurements performed in a `multi-reversible' transformation. We show that following such a protocol the system is at each step described by a generalization of the Boltzmann-Gibbs distribution, that has been studied in the past. Guerra's bound interpolation scheme for spin-glasses is closely related to this: by translating it into a dynamical setting, we show how it may actually be implemented in practice. The phase diagram plane of temperature vs "number of replicas", long studied in spin-glasses, in our approach becomes simply that of the two temperatures the system is in contact with. We suggest that this representation may be used to directly compare phenomenological and mean-field inspired models.Finally, we show how an approximate out of equilibrium probability distribution may be inferred experimentally on the basis of measurements along an almost reversible transformation.
description: 23 pages, 8 figures
A Quasi-sure Non-degeneracy Property for the Brownian Rough Path
Creators: name: Boedihardjo, Horatio
name: Geng, Xi
name: Liu, Xuan
name: Qian, Zhongmin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: In the present paper, we are going to show that outside a slim set in the sense of Malliavin (or quasi-surely), the signature path (which consists of iterated path integrals in every degree) of Brownian motion is non-self-intersecting. This property relates closely to a non-degeneracy property for the Brownian rough path arising naturally from the uniqueness of signature problem in rough path theory. As an important consequence we conclude that quasi-surely, the Brownian rough path does not have any tree-like pieces and every sample path of Brownian motion is uniquely determined by its signature up to reparametrization.
description: 23 pages
Self-gravitating accretion discs
Creators: name: Lodato, G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: I review recent progresses in the dynamics and the evolution of self-gravitating accretion discs. Accretion discs are a fundamental component of several astrophysical systems on very diverse scales, and can be found around supermassive black holes in Active Galactic Nuclei (AGN), and also in our Galaxy around stellar mass compact objects and around young stars. Notwithstanding the specific differences arising from such diversity in physical extent, all these systems share a common feature where a central object is fed from the accretion disc, due to the effect of turbulence and disc instabilities, which are able to remove the angular momentum from the gas and allow its accretion. In recent years, it has become increasingly apparent that the gravitational field produced by the disc itself (the disc's self-gravity) is an important ingredient in the models, especially in the context of protostellar discs and of AGN discs. Indeed, it appears that in many cases (and especially in the colder outer parts of the disc) the development of gravitational instabilities can be one of the main agents in the redistribution of angular momentum. In some cases, the instability can be strong enough to lead to the formation of gravitationally bound clumps within the disc, and thus to determine the disc fragmentation. As a result, progress in our understanding of the dynamics of self-gravitating discs is essential to understand the processes that lead to the feeding of both young stars and of supermassive black holes in AGN. At the same time, understanding the fragmentation conditions is important to determine under which conditions AGN discs would fragment and form stars and whether protostellar discs might form giant gaseous planets through disc fragmentation.
description: in press, La Rivista del Nuovo Cimento, 30, 293 (2007)
Comparison of Spin-Wave Modes in Connected and Disconnected Artificial Spin Ice Nanostructures Using Brillouin Light Scattering Spectroscopy
Creators: name: Chaurasiya, Avinash Kumar
name: Mondal, Amrit Kumar
name: Gartside, Jack C.
name: Stenning, Kilian D.
name: Vanstone, Alex
name: Barman, Saswati
name: Branford, Will R.
name: Barman, Anjan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Artificial spin ice systems have seen burgeoning interest due to their intriguing physics and potential applications in reprogrammable memory, logic and magnonics. Integration of artificial spin ice with functional magnonics is a relatively recent research direction, with a host of promising results. As the field progresses, direct in-depth comparisons of distinct artificial spin systems are crucial to advancing the field. While studies have investigated the effects of different lattice geometries, little comparison exists between systems comprising continuously connected nanostructures, where spin-waves propagate via dipole-exchange interaction, and systems with nanobars disconnected at vertices where spin-wave propagation occurs via stray dipolar-field. Gaining understanding of how these very different coupling methods affect both spin-wave dynamics and magnetic reversal is key for the field to progress and provides crucial system-design information including for future systems containing combinations of connected and disconnected elements. Here, we study the magnonic response of two kagome spin ices via Brillouin light scattering, a continuously connected system and a disconnected system with vertex gaps. We observe distinct high-frequency dynamics and magnetization reversal regimes between the systems, with key distinctions in spin-wave localization and mode quantization, microstate-trajectory during reversal and internal field-profiles. These observations are pertinent for the fundamental understanding of artificial spin systems and broader design and engineering of reconfigurable functional magnonic crystals.
Backward problems for stochastic differential equations on the Sierpinski gasket
Creators: name: Liu, Xuan
name: Qian, Zhongmin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 28A80, 60H10, 60H30

description: In this paper, we study the non-linear backward problems (with deterministic or stochastic durations) of stochastic differential equations on the Sierpinski gasket. We prove the existence and uniqueness of solutions of backward stochastic differential equations driven by Brownian martingale (defined in Section [sec:-1]) on the Sierpinski gasket constructed by S. Goldstein and S. Kusuoka. The exponential integrability of quadratic processes for martingale additive functionals is obtained, and as an application, a Feynman-Kac representation formula for weak solutions of semi-linear parabolic PDEs on the gasket is also established.
description: 30 pages
Finding Peace for Economists in Universities
Creators: name: Johnson, Marc A.
name: Johnson, Marc A.
Publisher: name: Unknown
Year: 2007
Subjects: subject: Public Economics
subject: Teaching/Communication/Extension/Profession
subject: demand for policy analysis
subject: public policy
subject: university decision making

description: Evidence suggests that economists and agricultural economists have an unusual ability to create anxiety for university administration. Interviewers with university provosts and deans revealed support for faculty conducting relevant policy analysis, and discomfort with economists' participation in internal university decision making. The conflict is addressed by considering the nature of the decision environment, specification of decision variables, and the demand for policy evaluation to inform economists how they might contribute their expertise in a peaceful and effective manner. economists can help central administration, as policy makers, to establish systems of incentives, success metrics, and divisions of authority which match the locus of specialized knowledge.
The bar complex of an E-infinity algebra
Creators: name: Fresse, Benoit
Publisher: name: arXiv
Year: 2006
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 57T30, 55P48, 18G55, 55P35

description: The standard reduced bar complex B(A) of a differential graded algebra A inherits a natural commutative algebra structure if A is a commutative algebra. We address an extension of this construction in the context of E-infinity algebras. We prove that the bar complex of any E-infinity algebra can be equipped with the structure of an E-infinity algebra so that the bar construction defines a functor from E-infinity algebras to E-infinity algebras. We prove the homotopy uniqueness of such natural E-infinity structures on the bar construction. We apply our construction to cochain complexes of topological spaces, which are instances of E-infinity algebras. We prove that the n-th iterated bar complexes of the cochain algebra of a space X is equivalent to the cochain complex of the n-fold iterated loop space of X, under reasonable connectedness, completeness and finiteness assumptions on X.
description: 51 pages. Preprint put in Elsevier format. Minor additional writing corrections
Laryngeal phenomena in Tahltan
Creators: name: Bob, Tanya Marie
Publisher: name: University of British Columbia
Year: 2009

description: This thesis investigates the phonetic and phonological properties of laryngeal distinctions in the consonant inventory of Tahltan, a northern Athapaskan language. This thesis does not examine the phonetic properties of all Tahltan consonants. Instead, this thesis focuses on the phonetic acoustic properties of plain stop consonants, which have been described inconsistently in Tahltan, to determine their laryngeal specification. This thesis also examines the observed patterns of behavior governing syllable structure to help determine the laryngeal specification of consonants in Tahltan. In addition, several morphophonemic processes are examined to determine the phonological laryngeal specification of consonants in Tahltan. Based on the phonetic findings, and observed patterns of behavior governing syllable structure, I will argue that stop consonants in Tahltan exhibit four laryngeal articulations: voiced, voiceless unaspirated voiceless aspirated and glottalized. Based on the morphophonemic evidence, I will argue that fricative consonants exhibit two laryngeal articulations: voiced and voiceless. Furthermore, I will argue that glottal stop is specified for the laryngeal specification [constricted glottis] (henceforth [CG]) and that [h] is specified for the laryngeal specification [spread glottis] (henceforth [SG]).
MPEC 2024-A96 : 2008 VK110
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2008 VK110

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Limitations of CMB B-mode template delensing
Creators: name: Lizancos, Antón Baleato
name: Challinor, Anthony
name: Carron, Julien
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Efforts to detect a primordial $B$-mode of CMB polarization generated by inflationary gravitational waves ought to mitigate the large variance associated with the $B$-modes produced by gravitational lensing, a process known as delensing. A popular approach to delensing entails building a lensing $B$-mode template by mimicking the lensing operation, either at gradient order or non-perturbatively, using high-resolution $E$-mode observations and some proxy of the lensing potential. By explicitly calculating all contributions to two-loop order in lensing to the power spectrum of $B$-modes delensed with such a template in the noise-free limit, we are able to show that: (i) corrections to the leading-order calculation of the lensing $B$-mode power spectrum only enter at the $O(1)\,\%$ level because of extensive cancellations between large terms at next-to-leading order; (ii) these cancellations would disappear if a gradient-order template were to be built from unlensed or delensed $E$-modes, giving rise to a residual delensing floor of $O(10)\,\%$ of the original power; (iii) new cancellations arise when the lensed $E$-modes are used in the gradient-order template, allowing for the delensing floor to be as low as $O(1)\,\%$ of the original power in practical applications of this method; and (iv) these new cancellations would disappear for a non-perturbative template constructed from the lensed $E$-modes, reintroducing a residual delensing floor of $O(10)\,\%$. We further show that the gradient-order template outperforms the non-perturbative one in realistic scenarios with noisy estimates of the $E$-mode polarization and lensing potential. We therefore recommend that in practical applications of $B$-mode template delensing, where the template is constructed directly from the (filtered) observed $E$-modes, the gradient-order approach should be used rather than a non-perturbative remapping.
description: 12 pages + references. 5 Figures. Published in PRD as an "Editor's suggestion"
A stochastic Pontryagin maximum principle on the Sierpinski gasket
Creators: name: Liu, Xuan
Publisher: name: arXiv
Year: 2017
Subjects: subject: Probability (math.PR)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: In this paper, we consider stochastic control problems on the Sierpinski gasket. An order comparison lemma is derived using heat kernel estimate for Brownian motion on the gasket. Using the order comparison lemma and techniques of BSDEs, we establish a Pontryagin stochastic maximum principle for these control problems. It turns out that the stochastic maximum principle on the Sierpinski gasket involves two necessity equations in contrast to its counterpart on Euclidean spaces. This effect is due to singularity between the Hausdorff measure and the energy dominant measure on the gasket, which is a common feature shared by many fractal spaces. The linear regulator problems on the gasket is also considered as an example.
description: 21 pages
General Recursion via Coinductive Types
Creators: name: Capretta, Venanzio
Publisher: name: arXiv
Year: 2005
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences
subject: F.3.1

description: A fertile field of research in theoretical computer science investigates the representation of general recursive functions in intensional type theories. Among the most successful approaches are: the use of wellfounded relations, implementation of operational semantics, formalization of domain theory, and inductive definition of domain predicates. Here, a different solution is proposed: exploiting coinductive types to model infinite computations. To every type A we associate a type of partial elements Partial(A), coinductively generated by two constructors: the first, return(a) just returns an element a:A; the second, step(x), adds a computation step to a recursive element x:Partial(A). We show how this simple device is sufficient to formalize all recursive functions between two given types. It allows the definition of fixed points of finitary, that is, continuous, operators. We will compare this approach to different ones from the literature. Finally, we mention that the formalization, with appropriate structural maps, defines a strong monad.
description: 28 pages
Parabolic type equations associated with the Dirichlet form on the Sierpinski gasket
Creators: name: Liu, Xuan
name: Qian, Zhongmin
Publisher: name: arXiv
Year: 2017
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 28A80, 60J45

description: By using the analytic tools of Dirichlet forms, we initiate a study of some non-linear parabolic equations on Sierpinski gasket, motivated by modellings of fluid flows along a fractal (which can be considered as a simplified rough porous medium). Unlike the regular spaces case, such equation involving a convection term must take a quite different form and the convection term must be singular to the "linear part" which is determined the heat semigroup. In order to study these parabolic type equations, a new kind of Sobolev inequalities for the Dirichlet form on the gasket will be established as an effective tool for our study. These Sobolev inequalities, which are interesting by their own and in contrast to the case of Euclidean spaces, involve two $L^p$ norms with respect two mutually singular measures. By examining properties of a singular convolution of the associated heat semigroup, we derive the space-time regularity of solutions to the parabolic equations under a few technical conditions. The Burgers equations on the Sierpinski gasket are also studied, for which a maximum principle for solutions is derived using techniques from backward stochastic differential equations, and the existence and uniqueness as well as the regularity of solutions are obtained.
description: 30 pages
On the topological cyclic homology of the algebraic closure of a local field
Creators: name: Hesselholt, Lars
Publisher: name: arXiv
Year: 2005
Subjects: subject: Number Theory (math.NT)
subject: K-Theory and Homology (math.KT)
subject: FOS: Mathematics

description: The cyclotomic trace provides a comparison of the algebraic K-theory spectrum and a pro-spectrum TR that is built from the cyclic fixed points of topological Hochschild homology. In a previous paper with Ib Madsen, we used this comparison and an approximate evaluation of the structure of the pro-spectrum TR to evaluate the p-adic K-groups of a local field K of mixed characteristic (0,p) with perfect residue field. In this paper we completly determine the structure of the pro-spectrum TR for an algebrac closure of the local field K. This leads us to formulate a conjecture for the structure of the pro-spectrum TR for the field K. We also determine the structure of the absolute de Rham-Witt complex of the valuation ring R in the algebraic closure of K. The group in degree one is a p-divisible group whose Tate module is free module of rank one over the ring of Witt vectors in R. We give an explicit generator of this Tate module.
The Effect of Innovation on Agricultural and Agri-food Exports in OECD Countries
Creators: name: Ghazalian, Pascal L.
name: Furtan, William Hartley
name: Ghazalian, Pascal L.
name: Furtan, William Hartley
Publisher: name: Unknown
Year: 2007
Subjects: subject: International Relations/Trade
subject: Research and Development/Tech Change/Emerging Technologies
subject: agriculture
subject: food
subject: gravity equation
subject: innovation
subject: OECD
subject: R&D

description: This paper investigates the effect of innovation on primary agricultural and processed food product exports among the Organization for Economic Cooperation and Development (OECD) countries. A theoretical gravity equation that accounts for innovation is derived. The empirical exercise uses panel data sets covering 21 OECD countries for the period 1990-2003. The R&D capital stock is employed as a tangible way of measuring innovation. Empirical results show that R&D has enhanced exports in the primary agricultural sector. Meanwhile, the market expansion effect of R&D appears to be more than offset by the market power effect in the food processing sector, resulting in a decrease in exports. Also, evidence was found of a positive vertical channeling effect through which R&D in the primary agricultural sector increases exports of processed food products.
One-loop integrand from generalised scattering equations
Creators: name: Abhishek, Md.
name: Hegde, Subramanya
name: Saha, Arnab Priya
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Generalised bi-adjoint scalar amplitudes, obtained from integrations over moduli space of punctured $\mathbb{CP}^{k-1}$, are novel extensions of the CHY formalism. These amplitudes have realisations in terms of Grassmannian cluster algebras. Recently connections between one-loop integrands for bi-adjoint cubic scalar theory and $\mathcal{D}_n$ cluster polytope have been established. In this paper using the $\text{Gr}\left(3,6\right)$ cluster algebra, we relate the singularities of $\left(3,6\right)$ amplitude to four-point one-loop integrand in the bi-adjoint cubic scalar theory through the $\mathcal{D}_{4}$ cluster polytope. We also study factorisation properties of the $(3,6)$ amplitude at various boundaries in the worldsheet.
description: Some references are added
A new approach to quantum backflow
Creators: name: Penz, Markus
name: Grübl, Gebhard
name: Kreidl, Sabine
name: Wagner, Peter
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We derive some rigorous results concerning the backflow operator introduced by Bracken and Melloy. We show that it is linear bounded, self adjoint, and not compact. Thus the question is underlined whether the backflow constant is an eigenvalue of the backflow operator. From the position representation of the backflow operator we obtain a more efficient method to determine the backflow constant. Finally, detailed position probability flow properties of a numerical approximation to the (perhaps improper) wave function of maximal backflow are displayed.
description: 12 pages, 8 figures
A Choice Model with Systematic Structures in Decision Weights
Creators: name: Hu, Wuyang
name: Hu, Wuyang
Publisher: name: Unknown
Year: 2007
Subjects: subject: Demand and Price Analysis
subject: logit models
subject: stated choice
subject: structural adjustment
subject: weights

description: This article introduces a discrete choice model which incorporates a nonlinear structural adjustment to the standard utility coefficients or decision weights. The proposed model is theoretically and empirically appealing when compared to several alternative approaches, and it can be estimated by conventional maximum likelihood. Application of the proposed model in a case study shows that it outperforms two competing approaches in model fit. Given its simplicity, this model is also capable of revealing consumers' heterogeneous choices. It is shown that based on consumers' different characteristics, their product choice and its welfare implications are also potentially different.