Top Research Papers on Space

This work provides the first unambiguous evidence for a hippocampal representation of a conceptual space compared with a general feature-based space, by showing that the hippocampal distance signal selectively reflects the mapping of specifically conceptually relevant rather than of all feature dimensions.

This open access book provides a comprehensive view on data ecosystems and platform economics from methodical and technological foundations up to reports from practical implementations and applications in various industries.\nTo this end, the book is structured in four parts: Part I “Foundations and Contexts” provides a general overview about building, running, and governing data spaces and an introduction to the IDS and GAIA-X projects. Part II “Data Space Technologies” subsequently details various implementation aspects of IDS and GAIA-X, including eg data usage control, the usage of blockch...

Developer productivity is about more than an individual's activity levels or the efficiency of the engineering systems relied on to ship software, and it cannot be measured by a single metric or dimension. The SPACE framework captures different dimensions of productivity, and here we demonstrate how this framework can be used to understand productivity in practice and why using it will help teams better understand developer productivity and create better measures to inform their work and teams.

The shell bound by the Karman line at a height of ~80–100 km above the Earth’s surface and geosynchronous orbit at ~36,000 km is defined as the orbital space surrounding the Earth. It is within this region, and especially in low Earth orbit, where environmental issues are becoming urgent because of the rapid growth of the anthropogenic space object population, including satellite ‘mega-constellations’. In this Perspective, we summarize the case for considering the orbital space around the Earth as an additional ecosystem, subject to the same care and concerns, and the same broad regulations as...

Abstract The article investigates the control of the platform labour process by means of the digital production of space and how workers resist it. The segment of German platform‐mediated food delivery is examined via qualitative interviews and auto‐ethnography. It is shown how the platforms create different spaces to efficiently coordinate and control mobile delivery gig work. Steered by geolocalisation and geofencing, the couriers operate autonomously in spatial corridors defined by the platforms. The agency of the riders is thus limited, but they are occasionally able to undermine the platf...

Urban green spaces (UGS) offer a wide range of ecosystem services to city dwellers, contributing to their health and well-being. The resources of formally designated UGS, such as parks and forests, are frequently underprovided, however. This results in unequal access to UGS, which has become an environmental justice issue. We investigated the potential of informal green spaces (IGS) to complement existing formal UGS to reduce distributional inequity in UGS availability. We focused on the most vulnerable groups of citizens, children and elderly residents, for whom the availability of UGS plays ...

Abstract The Galilean moons play major roles in the giant magnetosphere of Jupiter. At the same time, the magnetospheric particles and fields affect the moons. The impact of magnetospheric ions on the moons' atmospheres supplies clouds of escaping neutral atoms that populate a substantial fraction of their orbits. At the same time, ionization of atoms in the neutral cloud is the primary source of magnetospheric plasma. The stability of this feedback loop depends on the plasma/moon‐atmosphere interaction. The purpose of this review is to describe the physical processes that shape the space envi...

A bstract The covariant phase space method of Iyer, Lee, Wald, and Zoupas gives an elegant way to understand the Hamiltonian dynamics of Lagrangian field theories without breaking covariance. The original literature however does not systematically treat total derivatives and boundary terms, which has led to some confusion about how exactly to apply the formalism in the presence of boundaries. In particular the original construction of the canonical Hamiltonian relies on the assumed existence of a certain boundary quantity “ B ”, whose physical interpretation has not been clear. We here give an...

Space-time wave packets (STWPs) constitute a broad class of pulsed optical fields that are rigidly transported in linear media without diffraction or dispersion, and are therefore propagation-invariant in the absence of optical nonlinearities or waveguiding structures. Such wave packets exhibit unique characteristics, such as controllable group velocities in free space and exotic refractive phenomena. At the root of these behaviors is a fundamental feature underpinning STWPs: their spectra are not separable with respect to the spatial and temporal degrees of freedom. Indeed, the spatiotemporal...

This open access book presents the key aspects of statistics in Wasserstein spaces, i.e. statistics in the space of probability measures when endowed with the geometry of optimal transportation. It introduces the fundamentals of this topic while providing an overview to invite further research.

The past decade has experienced an increase in the number of studies on organizational space or where work occurs. A number of these studies challenge traditional views of organizational space as a fixed, physical workspace because researchers fail to account for the spatial dynamics that they observe. New technologies, shifting employee-employer relations, and burgeoning expectations of the contemporary workforce blur boundaries between home and work, connect people and things that historically could not be linked, and extend workspaces to nearly everywhere, not just office buildings. Researc...

This textbook deals with the requirements of space physics. The first part starts with a description of the Earth's plasma environment, followed by a derivation of single particle motions in electromagnetic fields, with applications to the Earth's magnetosphere. Then the origin and effects of collisions and conductivities, formation of the ionosphere, magnetospheric convection and dynamics, and solar wind-magnetosphere coupling are discussed.The second part of the book presents a more theoretical foundation of plasma physics, starting from kinetic theory. Introducing moments of the distributio...

Conventional π-conjugated luminophores suffer from problems such as emission quenching, biotoxicity, environmental pollution, etc. The emerging nonconjugated and nonaromatic clusteroluminogens (CLgens) are expected to overcome these stubborn drawbacks, so research of CLgens shows great significance not only for practical application but also for the construction of fundamental photophysical theories. This perspective summarizes the unusual features of CLgens in comparison to traditional chromophores, such as nonconjugated molecular structures, unmatched absorption and excitation, excitation-de...

A bstract We consider black holes in 2d de Sitter JT gravity coupled to a CFT, and entangled with matter in a disjoint non-gravitating universe. Tracing out the entangling matter leaves the CFT in a density matrix whose stress tensor backreacts on the de Sitter geometry, lengthening the wormhole behind the black hole horizon. Naively, the entropy of the entangling matter increases without bound as the strength of the entanglement increases, but the monogamy property predicts that this growth must level off. We compute the entropy via the replica trick, including wormholes between the replica c...

Recent theoretical and methodological advances in urban sociology, including spatially located data, provide new opportunities to consider the joint influence of mobility and place in urban social life. This review defines the concept of activity space, describes its origins in urban sociology, and examines the extent to which activity space approaches advance sociological research in four substantive domains—spatial inequality and segregation, social connectedness and engagement, crime and offending patterns, and health and health-related behavior. It next describes the evolution of methods f...

There is an urgent demand to introduce a concept, that is, confined space, which is capable of precisely monitoring the process of elec-tron/charge transfer by a designable and controllable sensing interface whose size is comparable with that of single entities.

Public Places Urban Spaces provides a comprehensive overview of the principles, theory and practices of urban design for those new to the subject and for those requiring a clear and systematic guide. In this new edition the book has been extensively revised and restructured. Carmona advances the idea of urban design as a continuous process of shaping places, fashioned in turn by shifting global, local and power contexts. At the heart of the book are eight key dimensions of urban design theory and practice—temporal, perceptual, morphological, visual, social, functional—and two new process dimen...

The Micius satellite, launched from China in August 2016, is the first and only satellite dedicated entirely to quantum experiments. The ultralow loss transmission of photons on most of the path between ground and space enables quantum communication capabilities that are still far from being realized. This review details the commissioning of Micius as a full quantum communications system, and describes the achievement of global-scale quantum key distribution, entanglement distribution, and other fundamental studies, with this unique space-based system.

We consider black holes in 2d de Sitter JT gravity coupled to a CFT, and entangled with matter in a disjoint non-gravitating universe. Tracing out the entangling matter leaves the CFT in a density matrix whose stress tensor backreacts on the de Sitter geometry, lengthening the wormhole behind the black hole horizon. Naively, the entropy of the entangling matter increases without bound as the strength of the entanglement increases, but the monogamy property predicts that this growth must level off. We compute the entropy via the replica trick, including wormholes between the replica copies of t...

The covariant phase space method of Iyer, Lee, Wald, and Zoupas gives an elegant way to understand the Hamiltonian dynamics of Lagrangian field theories without breaking covariance. The original literature however does not systematically treat total derivatives and boundary terms, which has led to some confusion about how exactly to apply the formalism in the presence of boundaries. In particular the original construction of the canonical Hamiltonian relies on the assumed existence of a certain boundary quantity “B”, whose physical interpretation has not been clear. We here give an algorithmic...