Field In Space Research Articles

From order to chaos. How the Brexit economic expert discourse articulates structural dissolution in times of COVID-19 crisis

This paper analyses the transformation of identities and institutions of economic experts as politico-economic professionals brought about by the Brexit process between 2016 and 2020. In order to understand the transformation from order to chaos in times of COVID-19, a mixed methods approach is applied. In a first step, a discourse analysis of two competing letters from two different groups of economists is carried out. One letter was published by “Economists for Remain” before the Brexit referendum in 2016; the other letter was published by a group called “Economists for Free Trade”, arguing for leaving the EU. In a second step, we conduct a field and social space analysis of economists who signed the letters in order to analyse their social backgrounds and professional positions within the UK academic, media, political and economic system. The paper shows that members of both groups take significantly different positions. In a final step, we conducted interviews in 2019/20 with selected members of each group. Here we show how the professional system of UK economic governmentality enters a state of crisis. The paper finally argues that contemporary nationalist movements cannot provide a new social order. They lead societies into chaos instead.

The iVAN Project: an innovative solution to meet the challenges in trial recruitment during a global pandemic

AbstractPurposeCOVID‐19 has greatly affected the number of patients willing and able to attend hospital, with research activity also greatly impacted. Imperial College Ophthalmology Research Group (ICORG) have observed clinical backlogs and a 77% decrease in trial patient recruitment. As a first of its kind, this project aims to combat clinic waiting lists and patient confidence in trial involvement through creating a safe, flexible and decentralised healthcare environment with iVAN, a mobile research unit.MethodsA survey of outpatients was performed exploring attitudes towards visiting hospital for clinical and research reasons amidst a pandemic. A vehicle was equipped with state‐of‐the‐art clinical research facilities in a COVID‐safe environment. A multi‐stage approach was taken in order to achieve relevant driving and roadworthiness certification, multi‐disciplinary involvement and healthcare network planning in order to ensure the smooth progression of the project. A pilot period of clinical visits was carried out and evaluated in close vicinity to the hospital.ResultsOf the 53 patients surveyed, 60% percent of patients were not willing to take part in clinical trials with others having concerns related to travel and being in the hospital. The final layout of the vehicle includes imaging devices, a visual field analyser, IT equipment and space for staff to see patients. Social distancing and infection control have been ensured to provide a pleasant and safe working environment. A pilot period is underway assessing staff and patient satisfaction along with capacity and trial data runs, with future plans involving satellite clinics in the community.ConclusionsFlexible and innovative service provision continues to be required to minimise morbidity attributable to the pandemic. The iVan has the facilities to bring decentralised, specialist ophthalmic care into local communities in a COVID‐safe manner, whilst being a useful tool to engage future research participants.

The Effect of Corona Wire Position and Radius in a Duct-Type ESP with Wavy Collecting Plates

Electrostatic precipitators (ESPs) have become one of the most effective methods for removing harmful particles from various industries. Many investigations in this subject are constantly developing due to the inherent benefits of using an ESP, and there are many robust initiatives taking place today all over the world. Different configurations of collection and discharging electrodes must be investigated to improve the ESP performance of ESPs. Many studies are working to enhance existing models in different ways. The geometry of the electrodes and the collecting plates is one area that could be improved. This paper investigates the wavy designs of collecting electrodes with varied corona electrode radius (range of variable corona radius (0.07-0.6 mm)) and position in a single-stage ESP. Wavy plates (WPs) and Inverted wavy plates (InvWPs) are compared to flat plates (FPs) using a numerical simulation tool. The results of this work show the impact of changing the corona radius when wavy and inverted wavy collecting electrodes are used on the electric potential, electric field strength, current density, and space charge density distribution, and particle collection efficiency. When compared to InvWPs and FPs, WPs show the highest performance in this range of particles. Although InvWPs can be utilized to reduce current density or space charge density, they do not increase particle collection efficiency.

High-throughput plant phenotyping for improved turfgrass breeding applications

Turfgrasses are used extensively throughout the world, and there is a steadfast demand to develop turfgrass varieties with improved abiotic and biotic stress tolerances that will perform well with limited management inputs. Modern breeding programs incorporate advanced breeding strategies such as DNA sequencing and high-throughput phenotyping with traditional breeding strategies to identify and select germplasm and genes of interest. Molecular biology methods and DNA sequencing technology have rapidly increased in recent years, and, as a result, plant phenotyping is currently a bottleneck in the process of advancing breeding programs. Recent advances in remote sensing technology have offered improved, non-destructive plant phenotyping approaches such as visible light imaging, spectral imaging, infrared thermal imaging, range sensing, and fluorescence imaging. Integrated mobile and time efficient platforms are being developed, coupling remote sensing with robotics and unmanned aerial systems technology for high-throughput plant phenotyping applications across large field spaces. Modern turfgrass breeding programs will continue to research, develop, and implement remote sensing technologies to assess larger numbers of genotypes and identify elite germplasm. All together, these efforts will improve cultivar development efficiency and aid plant breeders in developing improved turfgrass cultivars to meet current and future demands of the turfgrass industry. This review provides an overview of ground- and aerial-based plant phenotyping platforms, with particular emphasis placed on applications to turfgrass breeding practices. Similarly, imaging technologies that have been used in various plant breeding programs are discussed, with indications as to how those technologies could be applicable to turfgrass breeding programs.

THE PECULARITIES OF THE VERBALIZATION OF THE NOTION SPACE EXPLORATION IN ENGLISH (A STUDY OF THE NOVEL “THE MARTIAN” BY ANDY WEIR)

The article deals with the notion of Space Exploration. Its semantic and structural peculiarities have been analysed. The notion Space Exploration has been studied and foregrounded in fiction, namely in the science-popular novel. Several lexicographic resources have been applied for the comprehensive analysis. The study has been conducted in accordance with existent researches in the field. The terms that represent space sphere have been specified in fiction that cannot be treated as typical context. The etymological transformation of the lexeme has been traced. The evolution of the corresponding notion in Ukrainian has been taken into account. The notion Space Exploration has been admitted to be the nucleus of the lexico-semantic field Space Exploration. The meaning of the lexeme has been worked out in both ways – its practical usage and theoretical definitions. It has been illustrated that Space Exploration can alter its meaning contextually and some semantic alternatives have been introduced. The structure of the lexico-semantic field Space Exploration has been organized. Lexico-semantic groups that constitute the lexico-semantic field under consideration have been outlined. Nuclear lexemes have been defined. Some lexicosemantic groups have been further structured into lexico-semantic subgroups because of their thematic heterogeneity. The complexity of the notion Space Exploration has also contributed to the detailed structural organisation of the field. The peculiarities of lexical units and specificity of their functioning in fiction have been highlighted as well. The frequency of usage has been accentuated. Space Equipment has been acknowledged as the only lexico-semantic subgroup comprising nouns exclusively. It has been emphasized that acronyms are often found in fiction to represent the sphere of space. It has been found out that all lexico-semantic groups and subgroups are interconnected whereas the boundaries are not distinct.

Analysis of Enhanced Oil Recovery Technology in Extra-high Water Cut Period in Oilfield

Most onshore oil fields in China are in the later stage of development, and the water content is more than 90%, which increases the difficulty of remaining oil mining. In order to improve the oil production, it is necessary to develop a variety of oil recovery technologies, increase the oil field space pressure, weaken the oil viscosity, and improve the recovery factor. Taking L oilfield as an example, the paper briefly expounds the characteristics of extra-high water cut period, and on this basis, puts forward recovery technology, grasps development rules, and realizes technological innovation. The accumulative oil production reaches 2.32 million tons, and the recovery factor increases by 9%, thus providing reference for related workers.

The Higgs mechanism and geometrical flows for two-manifolds

Using Perelman’s approach for geometrical flows in terms of an entropy functional, the Higgs mechanism is studied dynamically along flows defined in the space of parameters and in fields space. The model corresponds to two-dimensional gravity that incorporates torsion as the gradient of a Higgs field, and with the reflection symmetry to be spontaneously broken. The results show a discrete mass spectrum and the existence of a mass gap between the Unbroken Exact Symmetry and the Spontaneously Broken Symmetry scenarios. In the latter scenario, the geometries at the degenerate vacua correspond to conformally flat manifolds without torsion; twisted two-dimensional geometries are obtained by building perturbation theory around a ground state; the tunneling quantum probability between vacua is determined along the flows.

Fischer Decomposition of Massless Fields for Spin 3/2 in Dimension 4

As an analogue of the massless field equations in Euclidean space, we consider the so-called generalized Cauchy–Riemann equations introduced by E. Stein and G. Weiss. In the spin 1/2 case these equations reduce to the Dirac equation for spin 1/2 fields, which was thoroughly and intensively studied in Clifford analysis. For general spin it was recently shown that, in dimension 4, homogenous solutions form irreducible Spin modules. The next step then is to describe the corresponding Fischer decomposition, i.e. an irreducible decomposition of the space of spinor fields, which is well-known for spin 1/2 and for spin 1. The main aim of the present paper is to describe, still in dimension 4, the Fischer decomposition for spin 3/2.

Asymptotic observables and the swampland

We show that constraints on scalar field potentials and towers of light massive states in asymptotic limits of scalar field space (as posited by the de Sitter Conjecture and the Swampland Distance Conjecture, respectively) are correlated with the prospects for defining asymptotic observables in expanding FRW cosmologies. The observations of a "census taker" in an eternally inflating cosmology are further related to the question of whether certain domain walls satisfy a version of the Weak Gravity Conjecture. This suggests that answers to fundamental questions about asymptotic observables in cosmology could help shed light on the Swampland program, and vice versa.

Duality, Generalized Global Symmetries and Jet Space Isometries

We revisit universal features of duality in linear and nonlinear relativistic scalar and Abelian 1-form theories with single or multiple fields, which exhibit ordinary or generalized global symmetries. We show that such global symmetries can be interpreted as generalized Killing isometries on a suitable, possibly graded, target space of fields or its jet space when the theory contains higher derivatives. This is realized via a generalized sigma model perspective motivated from the fact that higher spin particles can be Nambu–Goldstone bosons of spontaneously broken generalized global symmetries. We work out in detail the 2D examples of a compact scalar and the massless Heisenberg pion fireball model and the 4D examples of Maxwell, Born–Infeld, and ModMax electrodynamics. In all cases we identify the ’t Hooft anomaly that obstructs the simultaneous gauging of both global symmetries and confirm the anomaly matching under duality. These results readily generalize to higher gauge theories for p-forms. For multifield theories, we discuss the transformation of couplings under duality as two sets of Buscher rules for even or odd differential forms.

Classification of static asymptotically flat spacetimes with a photon sphere in Einstein-multiple-scalar field theory

In the present paper we consider the Einstein-multiple-scalar field theory. When the target space of the scalar fields is a complete, simply connected Riemannian manifold with non-positive sectional curvature we prove that the static and asymptotically flat solutions which posses a photon sphere are uniquely specified by their asymptotic data, i.e. by their mass, scalar charges and asymptotic values of the scalar fields. The unique solution with a photon sphere and prescribed asymptotic data is explicitly constructed.

Homotopy data as part of the lattice field: A first study

Fields exhibit a variety of topological properties, like different topological charges, when field space in the continuum is composed by more than one topological sector. Lattice treatments usually encounter difficulties describing those properties. In this work, we show that by augmenting the usual lattice fields to include extra variables describing local topological information (more precisely, regarding homotopy), the topology of the space of fields in the continuum is faithfully reproduced in the lattice. We apply this extended lattice formulation to some simple models with nontrivial topological charges, and we study their properties both analytically and via Monte Carlo simulations.

Deformations of supergravity and supersymmetry anomalies

We present a BRST analysis of supersymmetry anomalies of mathcal{N} = 1 supersymmetric quantum field theories with anomalous R symmetry. To this end, we consider the coupling of the matter theory to classical mathcal{N} = 1 new minimal supergravity. We point out that a supersymmetry anomaly cocycle associated to the U(1)R field does exist for this theory. It is non-trivial in the space of supergravity fields (and ghosts), but it becomes BRST-exact in the functional space that includes antifields. Equivalently, the U(1)R supersymmetry anomaly cocycle vanishes “on-shell”. It is therefore removable. However, to remove it — precisely because it is not trivial in the smaller space of fields — one needs to deform the supergravity BRST operator. This deformation is triggered, at first order in the anomaly coefficient, by a local operator S1 of ghost number 1. We give a cohomological characterization of S1 and compute it in full detail. At higher orders in the anomaly coefficient, we expect a priori that further deformations of the BRST rules are necessary.

Gravitational waves and dark photon dark matter from axion rotations

An axion rotating in field space can produce dark photons in the early universe via tachyonic instability. This explosive particle production creates a background of stochastic gravitational waves that may be visible at pulsar timing arrays or other gravitational wave detectors. This scenario provides a novel history for dark photon dark matter. The dark photons may be warm at a level detectable in future 21-cm line surveys. For a consistent cosmology, the radial direction of the complex field containing the axion must be thermalized. We explore a concrete thermalization mechanism in detail and also demonstrate how this setup can be responsible for the generation of the observed baryon asymmetry.

Pseudo-bounces vs. new instantons

Some false vacua do not decay via bounces. This usually happens when a flat direction of the tunneling action due to scale invariance is lifted to a sloping valley by a scale breaking perturbation, pushing the bounce off to infinity. We compare two types of alternative decay configurations that have been proposed recently to describe decay in such cases: pseudo-bounces and new instantons. Although both field configurations are quite similar, we find that the pseudo-bounce action is lower than the new instanton one and describes more faithfully the bottom of the action valley. In addition, pseudo-bounces cover a range of field space wider than new instantonsand, as a result, lead to a decay rate that can be lower than the one via new instantons by orders of magnitude.

Note on the bundle geometry of field space, variational connections, the dressing field method, & presymplectic structures of gauge theories over bounded regions

In this note, we consider how the bundle geometry of field space interplays with the covariant phase space methods so as to allow to write results of some generality on the presymplectic structure of invariant gauge theories coupled to matter. We obtain in particular the generic form of Noether charges associated with field-independent and field-dependent gauge parameters, as well as their Poisson bracket. We also provide the general field-dependent gauge transformations of the presymplectic potential and 2-form, which clearly highlights the problem posed by boundaries in generic situations. We then conduct a comparative analysis of two strategies recently considered to evade the boundary problem and associate a modified symplectic structure to a gauge theory over a bounded region: namely the use of edge modes on the one hand, and of variational connections on the other. To do so, we first try to give the clearest geometric account of both, showing in particular that edge modes are a special case of a differential geometric tool of gauge symmetry reduction known as the “dressing field method”. Applications to Yang-Mills theory and General Relativity reproduce or generalise several results of the recent literature.

Connected components of the space of proper gradient vector fields

We show that there exist two proper gradient vector fields on mathbb {R}^n which are homotopic in the category of proper maps but not homotopic in the category of proper gradient maps.

Isocurvature modes and non-Gaussianity in affine inflation

Inflationary dynamics driven by multiple fields, especially with nonminimal couplings, allow for highly interesting features such as isocurvature, non-Gaussianity, and preheating. In this paper, we study two-field inflation in the context of purely affine gravity, where the metrical structure results from the dynamics of the spacetime affine connection. We introduce a covariant formulation in the new framework and show that it leads to a curved field space which can produce conspicuous departure from the purely metric gravity. In the case where the fields are canonical, the field manifold gains a conformally flat shape. Interestingly, while the manifold is generally curved, it is possible to be flattened by allowing specific non-canonical field kinetic terms. This in turn simplifies the inflationary dynamics significantly while allowing for new predictions due to the effects of the nonminimal coupling function on the potential solely. We use this new feature in studying two-field inflation driven by quartic potentials for given parameter constants. We perform a numerical solution of the slow-roll dynamics and track the possible non-Gaussianity. We focus on field parameters that allow for spectral indices within the favored region of the Planck results. These are associated to tiny tensor-to-scalar ratios, $r \sim 10^{-6}$ for single field and $r \sim 10^{-4}$ for two-fields. We also show that two-field Higgs inflation may favor a curved field manifold.

Electron beam modeling and analyses of the electric field distribution and space charge effect

In electron beam technology, one of the critical focuses of research and development efforts is on improving the measurement of electron beam parameters. The parameters are closely related to the generation, emission, operation environment, and role of the electron beam and the corresponding medium. In this study, a field calculation method is proposed, and the electric field intensity distribution on the electron beam’s cross-section is analyzed. The characteristics of beam diffusion caused by the space charge effect are investigated in simulation, and the obtained data are compared with the experiment. The simulation demonstrated that the cross-sectional electric field distribution is primarily affected by the electron beam current, current density distribution, and electron beam propagation speed.

Absence of covariant singularities in pure gravity

The assumptions of the Hawking–Penrose singularity theorem are not covariant under field redefinitions. Following the works on the covariant formulation of quantum field theory initiated by Vilkovisky and DeWitt in the 80s, we propose to study singularities in field space, where the spacetime metric is treated as a coordinate along with the other fields in the theory. From this viewpoint, a spacetime singularity might be just a singularity in the field-space coordinates, analogously to the standard coordinate singularities in General Relativity. Objects invariant under field-space coordinate transformations can then reveal whether certain spacetime singularity is indeed singular. We recall that observables in quantum field theory are scalar functionals in field space. Therefore, in principle, spacetime singularities corresponding to regular field-space curvature invariants would not affect physical observables. In this paper, we show that the field-space Kretschmann scalar for a certain choice of the DeWitt field-space metric is everywhere finite. This fact could be interpreted as an indication that no singularities actually exist in pure gravity for any gravitational action. In particular, all vacuum singularities of General Relativity result from an unhappy choice of field variables. The extension to the case in which matter fields are present, as required by singularity theorems, is left for future development.