124,865 research outputs found
Energy stability analysis for a hybrid fluid-kinetic plasma model
In plasma physics, a hybrid fluid-kinetic model is composed of a
magnetohydrodynamics (MHD) part that describes a bulk fluid component and a
Vlasov kinetic theory part that describes an energetic plasma component. While
most hybrid models in the plasma literature are non-Hamiltonian, this paper
investigates a recent Hamiltonian variant in its two-dimensional configuration.
The corresponding Hamiltonian structure is described along with its Casimir
invariants. Then, the energy-Casimir method is used to derive explicit
sufficient stability conditions, which imply a stable spectrum and suggest
nonlinear stability
Picking up the pace in public services
Following the reforms of the public management system in the 1980s, legislative change and programmes of work to develop and shape the system have occurred at various times. The work programmes have tended to come and go, with mixed success, each designed around maintaining the strengths that accountability for outputs has brought to public sector agencies while increasing the focus on achieving outcomes
The turn to precarity in twenty-first century fiction
This is an open access article. Copyright © 2014 by Walter de Gruyter GmbH.Recent years have seen several attempts by writers and critics to understand the changed sensibility in post-9/11 fiction through a variety of new -isms. This essay explores this cultural shift in a different way, finding a ‘turn to precarity’ in twenty-first century fiction characterised by a renewal of interest in the flow and foreclosure of affect, the resurgence of questions about vulnerability and our relationships to the other, and a heightened awareness of the social dynamics of seeing. The essay draws these tendencies together via the work of Judith Butler in Frames of War, in an analysis of Trezza Azzopardi’s quasi-biographical study of precarious life, Remember Me
GIT Constructions of Moduli Spaces of Stable Curves and Maps
This largely expository paper first gives an introduction to Hilbert
stability and its use in Gieseker's GIT construction of . Then
I review recent work in this area--variants for unpointed curves that arise in
Hassett's log minimal model program, starting with Schubert's moduli space of
pseudostable curves, and constructions for weighted pointed stable curves and
for pointed stable maps due to Swinarski and to Baldwin and Swinarski
respectively. The focus is on the steps at which new ideas are needed. Finally,
I list open problems in the area, particularly some arising in the log minimal
model program that seem inaccessible to current techniques.Comment: 46 pages, 3 figures, written for Surveys in Differential Geometr
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