University of Portsmouth

About: University of Portsmouth is a education organization based out in Portsmouth, Portsmouth, United Kingdom. It is known for research contribution in the topics: Population & Galaxy. The organization has 5452 authors who have published 14256 publications receiving 424346 citations. The organization is also known as: Portsmouth and Gosport School of Science and Art & Portsmouth and Gosport School of Science and the Arts.

The Structure and Formation of Boson Stars

Abstract: Boson stars are gravitationally bound conglomerates of scalar particles. We review their structure and stability, and discuss possible means by which they might form in the early universe.

Dynamics of Assisted Inflation

Abstract: We investigate the dynamics of the recently proposed model of assisted inflation. In this model an arbitrary number of scalar fields with exponential potentials evolve towards an inflationary scaling solution, even if each of the individual potentials is too steep to support inflation on its own. By choosing an appropriate rotation in field space we can write down explicitly the potential for the weighted mean field along the scaling solution and for fields orthogonal to it. This demonstrates that the potential has a global minimum along the scaling solution. We show that the potential close to this attractor in the rotated field space is analogous to a hybrid inflation model, but with the vacuum energy having an exponential dependence upon a dilaton field. We present analytic solutions describing homogeneous and inhomogeneous perturbations about the attractor solution without resorting to slow-roll approximations. We discuss the curvature and isocurvature perturbation spectra produced from vacuum fluctuations during assisted inflation. PACS number: 98.80.Cq

Defining and Measuring Success in Online Citizen Science: A Case Study of Zooniverse Projects

Abstract: Although current literature highlights a wide variety of potential citizen science project outcomes, no prior studies have systematically assessed performance against a comprehensive set of criteria. The study reported here is the first to propose a novel framework for assessing citizen science projects against multiple dimensions of success. The authors apply this framework to a sample of projects that form part of the online Zooniverse platform and position these projects against a success matrix that measures both contribution to science and public engagement levels relative to other projects in the sample. Their results indicate that better-performing projects tend to be those that are more established, as well as those in the area of astronomy. Implications for citizen science practitioners include the need to consider the impact of core competencies on project performance, as well as the importance of relationships between the central organization and science teams.