1,308 research outputs found
Mass-varying neutrino in light of cosmic microwave background and weak lensing
We aim to constrain mass-varying neutrino models using large scale structure
observations and produce forecast for the Euclid survey. We investigate two
models with different scalar field potential and both positive and negative
coupling parameters \beta. These parameters correspond to growing or decreasing
neutrino mass, respectively. We explore couplings up to |\beta|<5. In the case
of the exponential potential, we find an upper limit on <0.004
at 2- level. In the case of the inverse power law potential the null
coupling can be excluded with more than 2-\sigma significance; the limits on
the coupling are \beta>3 for the growing neutrino mass and \beta<-1.5 for the
decreasing mass case. This is a clear sign for a preference of higher
couplings. When including a prior on the present neutrino mass the upper limit
on the coupling becomes |\beta|<3 at 2- level for the exponential
potential. Finally, we present a Fisher forecast using the tomographic weak
lensing from an Euclid-like experiment and we also consider the combination
with the cosmic microwave background (CMB) temperature and polarisation spectra
from a Planck-like mission. If considered alone, lensing data is more efficient
in constraining with respect to CMB data alone. There is, however,
a strong degeneracy in the \beta- plane. When the two data sets
are combined, the latter degeneracy remains, but the errors are reduced by a
factor ~2 for both parameters.Comment: 5 pages, 6 figures. Now published in A&A 500, 657-665 (2009
Womenâs participation in organisationally-assigned expatriation: an assignment type effect?
This article examines womenâs participation in long-term, short-term, rotational and commuter organisationally-assigned expatriation. It explores the effects of assignment length, pattern and accompanied/unaccompanied status on career contribution and home/family life outcomes. This triangulated research draws upon e-mail correspondence with 71 current female expatriates to learn about assignment types undertaken and future assignment intentions; and in-depth, semi-structured interviews with 26 of these assignees, and 14 Human Resource professionals in two case study oil and gas firms. This research is set within the theoretical frame of rational choice which suggests that couples engage co-operatively in their division of labour to maximise lifetime earnings, with women prioritising home and family over career prospects. The research finds that long-term assignments enable women to maximise or achieve high levels of both career and family outcomes. Alternative âflexpatriateâ assignments provide lower quality career potential and familial relationships, leading to career and/or family compromise/sacrifice. A model is presented to explain womenâs assignment preferences in meeting career and family life objectives, extending rational choice theory into the expatriate context. Increasing use of flexpatriation may inhibit expatriate gender diversity
Binomial Ideals and Congruences on Nn
ProducciĂłn CientĂficaA congruence on Nn is an equivalence relation on Nn that is compatible with the additive structure. If k is a field, and I is a binomial ideal in k[X1,âŠ,Xn] (that is, an ideal generated by polynomials with at most two terms), then I induces a congruence on Nn by declaring u and v to be equivalent if there is a linear combination with nonzero coefficients of Xu and Xv that belongs to I. While every congruence on Nn arises this way, this is not a one-to-one correspondence, as many binomial ideals may induce the same congruence. Nevertheless, the link between a binomial ideal and its corresponding congruence is strong, and one may think of congruences as the underlying combinatorial structures of binomial ideals. In the current literature, the theories of binomial ideals and congruences on Nn are developed separately. The aim of this survey paper is to provide a detailed parallel exposition, that provides algebraic intuition for the combinatorial analysis of congruences. For the elaboration of this survey paper, we followed mainly (Kahle and Miller Algebra Number Theory 8(6):1297â1364, 2014) with an eye on Eisenbud and Sturmfels (Duke Math J 84(1):1â45, 1996) and Ojeda and Piedra SĂĄnchez (J Symbolic Comput 30(4):383â400, 2000).National Science Foundation (grant DMS-1500832)Ministerio de EconomĂa, Industria y Competitividad (project MTM2015-65764-C3-1)Junta de Extremadura (grupo de investigaciĂłn FQM-024
Transforming practice, transforming practitioners:reflections on the TQFE in Scotland
This study offers reflections on the TQFE in Scotland as an example of the transformative professional learning model as identified by various authors. The focus of this study is the professional learning of lecturers in Scotlandâs colleges. Informed by wider considerations of teacher education more broadly, it will be of particular interest to those supporting a transformative model of professional learning in a variety of educational contexts. The research was undertaken as a collaborative initiative between each of the three universities which offer the TQFE in Scotland. Qualitative data are drawn from former TQFE participants and college mentors, and thematic analysis used to gain further insight from participant interviews. Findings highlight the transformative nature of the TQFE with an impact that is beyond the currency of the TQFE programme duration. The provision of transformative professional learning opportunities is now imperative given various pressures and tensions around the development of educators more generally and within contemporary Scottish Further Education in particular. Such pressures and tensions include: the varied demands within the Professional Standards for Lecturers in Scotlandâs Colleges, and the need for professional learning for college lecturers to go beyond a competency or tool-kit based approach and to be sustainable
Land, cane and coconuts : papers on the rural economy of Fiji
The three papers contained in this volume are the outcome of research into various aspects of employment generation and income distribution in Fiji agriculture, undertaken in 1982 and 1983. The papers were originally prepared as Working Papers for the Fiji Employment and Development Mission, which submitted its final report to the Fiji Government in 1984. Revised versions are published together here in order to make available to a wider readership the result of the research
Cosmological models with interacting components and mass-varying neutrinos
A model for a homogeneous and isotropic spatially flat Universe, composed of
baryons, radiation, neutrinos, dark matter and dark energy is analyzed. We
infer that dark energy (considered to behave as a scalar field) interacts with
dark matter (either by the Wetterich model, or by the Anderson and Carroll
model) and with neutrinos by a model proposed by Brookfield et al.. The latter
is understood to have a mass-varying behavior. We show that for a very-softly
varying field, both interacting models for dark matter give the same results.
The models reproduce the expected red-shift performances of the present
behavior of the Universe.Comment: 8 pages, 5 figures, to be published in Gravitation and Cosmolog
Neutrino clustering in growing neutrino quintessence
A growing neutrino mass can stop the dynamical evolution of a dark energy
scalar field, thus explaining the 'why now' problem. We show that such models
lead to a substantial neutrino clustering on the scales of superclusters.
Nonlinear neutrino lumps form at redshift z \sim 1 and could partially drag the
clustering of dark matter. If observed, large scale non-linear structures could
be an indication for a new attractive 'cosmon force' stronger than gravity.Comment: 6 pages, 5 figure
Five-Spin Supramolecule for Simulating Quantum Decoherence of Bell States
We report a supramolecule that contains five spins of two different types and with, crucially, two different and predictable interaction energies between the spins. The supramolecule is characterized, and the interaction energies are demonstrated by electron paramagnetic resonance (EPR) spectroscopy. Based on the measured parameters, we propose experiments that would allow this designed supramolecule to be used to simulate quantum decoherence in maximally entangled Bell states that could be used in quantum teleportation
Primordial Neutrinos, Cosmological Perturbations in Interacting Dark-Energy Model: CMB and LSS
We present cosmological perturbation theory in neutrinos probe interacting
dark-energy models, and calculate cosmic microwave background anisotropies and
matter power spectrum. In these models, the evolution of the mass of neutrinos
is determined by the quintessence scalar field, which is responsible for the
cosmic acceleration today. We consider several types of scalar field potentials
and put constraints on the coupling parameter between neutrinos and dark
energy. Assuming the flatness of the universe, the constraint we can derive
from the current observation is at the 95 % confidence
level for the sum over three species of neutrinos. We also discuss on the
stability issue of the our model and on the impact of the scattering term in
Boltzmann equation from the mass-varying neutrinos.Comment: 26 pages Revtex, 11 figures, Add new contents and reference
Supervision and Scholarly Writing: Writing to Learn - Learning to Write
This paper describes an action research project on postgraduate studentsâ scholarly writing in which I employed reflective approaches to examine and enhance my postgraduate supervisory practice. My reflections on three distinct cycles of supervision illustrate a shift in thinking about scholarly writing and an evolving understanding of how to support postgraduate studentsâ writing. These understandings provide the foundation for a future-oriented fourth cycle of supervisory practice, which is characterised by three principles, namely the empowerment of students as writers, the technological context of contemporary writing, and ethical issues in writing
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