1,137 research outputs found
Time and Time Functions in Parametrized Non-Relativistic Quantum Mechanics
The ``evolving constants'' method of defining the quantum dynamics of
time-reparametrization-invariant theories is investigated for a particular
implementation of parametrized non-relativistic quantum mechanics (PNRQM). The
wide range of time functions that are available to define evolving constants
raises issues of interpretation, consistency, and the degree to which the
resulting quantum theory coincides with, or generalizes, the usual
non-relativistic theory. The allowed time functions must be restricted for the
predictions of PNRQM to coincide with those of usual quantum theory. They must
be restricted to have a notion of quantum evolution in a time-parameter
connected to spacetime geometry. They must be restricted to prevent the theory
from making inconsistent predictions for the probabilities of histories.
Suitable restrictions can be introduced in PNRQM but these seem unlikely to
apply to a reparametrization invariant theory like general relativity.Comment: 18pages, 1postscript figure in separate file, uses REVTEX 3.
Transnationalism and Social Work Education
Transnational movements, networks, and relationships are everywhere in this âworld on the moveâ (Williams & Graham, 2014, p. i1). Transnational peoples maintain relationships of interdependence and support with families and communities in their places of origin, often returning regularly, while starting new lives and making new connections. Transnationalism is characterized by mobilities and networks, by social integration, and by extended and extensive relationship ties of family, neighborhood, religious faith, or combinations thereof (Valtonen, 2008). While disciplines across the world including sociology, human geography, and cultural anthropology engage with the implications of transnationalism (Bauböck & Faist, 2010), social work in England and mainland Europe has not achieved similar levels of engagement. As Cox and Geisen state: âthe social world is being transformed by migration and social work is playing catch-upâ (2014, p. i162)
Band Crossing and Novel Low-Energy Behaviour in a Mean Field Theory of a Three-Band Model on a Cu--O lattice
We study correlation effects in a three-band extended Hubbard model of Cu --
O planes within the 1/N mean field approach, in the infinite U limit. We
investigate the emerging phase diagram and discuss the low energy scales
associated with each region. With increasing direct overlap between oxygen
orbitals, , the solution displays a band crossing which, for an
extended range of parameters, lies close to the Fermi level. In turn this leads
to the nearly nested character of the Fermi surface and the resulting linear
temperature dependence of the quasi-particle relaxation rate for sufficiently
large T. We also discuss the effect of band crossing on the optical
conductivity and comment on the possible experimental relevance of our
findings.Comment: 12 pages, Latex-Revtex, 6 PostScript figures. Submitted to Phys. Rev.
Neoliberal paternalism and paradoxical subjects: Confusion and contradiction in UK activation policy
The twin thrusts of neoliberal paternalism have in recent decades become fused elements of diverse reform agendas across the advanced economies, yet neoliberalism and paternalism present radically divergent and even contradictory views of the subject across the four key spaces of ontology, teleology, deontology and ascetics. These internal fractures in the conceptual and resulting policy framework of neoliberal paternalism present considerable risks around unintended policy mismatch across these four spaces or, alternatively, offer significant flexibility for deliberate mismatch and âstoryingâ by policy makers. This article traces these tensions in the context of the UK Coalition governmentâs approach to the unemployed and outlines a current policy approach to employment activation that is filled with ambiguity, inconsistency and contradiction in its understanding of the subject, the âproblemâ and the policy âsolutionâ
The domestic and gendered context for retirement
Against a global backdrop of population and workforce ageing, successive UK governments have encouraged people to work longer and delay retirement. Debates focus mainly on factors affecting individualsâ decisions on when and how to retire. We argue that a fuller understanding of retirement can be achieved by recognizing the ways in which individualsâ expectations and behaviours reflect a complicated, dynamic set of interactions between domestic environments and gender roles, often established over a long time period, and more temporally proximate factors. Using a qualitative data set, we explore how the timing, nature and meaning of retirement and retirement planning are played out in specific domestic contexts. We conclude that future research and policies surrounding retirement need to: focus on the household, not the individual; consider retirement as an often messy and disrupted process and not a discrete event; and understand that retirement may mean very different things for women and for men
The Effects of Defamilisation and Familisation Measures on the Accumulation of Retirement Income for Women in the UK
This paper is concerned with the link between the effects of pro-market pension reforms
on women and familisation/defamilisation measures. It aims to contribute to the study of this
link in three ways. Firstly, it identifies defamilisation/familisation measures which have the
potential to reduce negative effects of pro-market pension measures on women. Secondly,
based on the examples from the UK, it shows that the governmentâs willingness to provide
sufficient defamilisation/familisation measures to assist women to deal with the negative
effects of the pro-market pension measures should not be taken for granted. Thirdly, it
suggests ways for tackling this problem
Quantum Zeno Effect and Light-Dark Periods for a Single Atom
The quantum Zeno effect (QZE) predicts a slow-down of the time development of
a system under rapidly repeated ideal measurements, and experimentally this was
tested for an ensemble of atoms using short laser pulses for non-selective
state measurements. Here we consider such pulses for selective measurements on
a single system. Each probe pulse will cause a burst of fluorescence or no
fluorescence. If the probe pulses were strictly ideal measurements, the QZE
would predict periods of fluorescence bursts alternating with periods of no
fluorescence (light and dark periods) which would become longer and longer with
increasing frequency of the measurements. The non-ideal character of the
measurements is taken into account by incorporating the laser pulses in the
interaction, and this is used to determine the corrections to the ideal case.
In the limit, when the time between the laser pulses goes to zero, no freezing
occurs but instead we show convergence to the familiar macroscopic light and
dark periods of the continuously driven Dehmelt system. An experiment of this
type should be feasible for a single atom or ion in a trapComment: 16 pages, LaTeX, a4.sty; to appear in J. Phys.
Active ageing, pensions and retirement in the UK
The ageing population has led to increasing concerns about pensions and their future
sustainability. Much of the dominant policy discourse around ageing and pension provision
over the last decade has focussed on postponing retirement and prolonging employment.
These measures are central to productive notions of âactive ageingâ. Initially the paper briefly
sets out the pension developments in the UK. Then it introduces active ageing and active
ageing policy, exploring its implications for UK pension provision. It demonstrates that a
more comprehensive active ageing framework, which incorporates a life-course perspective,
has the potential to assist the UK to respond to the challenges of an ageing population. In
doing so it needs to highlight older people as an economic and social resource, and reduce
barriers to older peopleâs participation in society
Charged Particles in a 2+1 Curved Background
The coupling to a 2+1 background geometry of a quantized charged test
particle in a strong magnetic field is analyzed. Canonical operators adapting
to the fast and slow freedoms produce a natural expansion in the inverse square
root of the magnetic field strength. The fast freedom is solved to the second
order.
At any given time, space is parameterized by a couple of conjugate operators
and effectively behaves as the `phase space' of the slow freedom. The slow
Hamiltonian depends on the magnetic field norm, its covariant derivatives, the
scalar curvature and presents a peculiar coupling with the spin-connection.Comment: 22 page
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