53 research outputs found
Gravitino perturbations in Schwarzschild black holes
We consider the time evolution of massless gravitino perturbations in
Schwarzschild black holes, and show that as in the case of fields of other
values of spin, the evolution comes in three stages, after an initial outburst
as a first stage, we observe the damped oscillations characteristic of the
quasinormal ringing stage, followed by long time tails. Using the sixth order
WKB method and Prony fitting of time domain data we determine the quasinormal
frequencies. There is a good correspondence between the results obtained by the
above two methods, and we obtain a considerable improvement with respect to the
previously obtained third order WKB results. We also show that the response of
a black hole depends crucially on the spin class of the perturbing field: the
quality factor becomes a decreasing function of the spin for boson
perturbations, whereas the opposite situation appears for fermion ones
Vacuum polarization effects on quasinormal modes in electrically charged black hole spacetimes
We investigate the influence of vacuum polarization of quantum massive fields
on the scalar sector of quasinormal modes in spherically symmetric black holes.
We consider the evolution of a massless scalar field on the spacetime
corresponding to a charged semiclassical black hole, consisting of the quantum
corrected geometry of a Reissner-Nordstr\"om black hole dressed by a quantum
massive scalar field in the large mass limit. Using a sixth order WKB approach
we find the shift in the quasinormal mode frequencies due to vacuum
polarization .Comment: 9 pages, 5 figures, typos added, references added and content change
The geodesic structure of the Schwarzschild Anti-de Sitter black hole
In the present work we found the geodesic structure of an AdS black hole. By
means of a detailed analyze of the corresponding effective potentials for
particles and photon, we found all the possible motions which are allowed by
the energy levels. Radial and non radial trajectories were exactly evaluated
for both geodesics. The founded orbits were plotted in order to have a direct
visualization of the allowed motions. We show that the geodesic structure of
this black hole presents new type of motions not allowed by the Schwarzschild
spacetime.Comment: 17 pages, 11 figure
An -frequency dynamics algorithm for gravitational waves
Coalescence of low mass compact binaries of neutron stars and black holes are
primary burst sources for LIGO and VIRGO.Of importance in the early stages of
observations will be the classification of candidate detections by source-type.
The diversity in source parameters and serendipity in any new window of
observations suggest to consider model-independent detection algorithms. Here a
frequency dynamics algorithm is described which extracts a trajectory in the
-plane from the noisy signal. The algorithm is studied in simulated
binary coalescence. Robust results are obtained with experimental noise data.
Experiments show the method to be superior to matched filtering in the presence
of model imperfections.Comment: to appear in Rapid Commun, Phys Rev
Physical and emotional nourishment: Food as the embodied component of loving care of elderly family relatives
Purpose
This purpose of this study is to examine the fluidity of family life which continues to attract attention. This is increasingly significant for the intergenerational relationship between adult children and their elderly parents. Using practice theory, the aims are to understand the role of food in elderly families and explore how family practices are maintained when elderly transition into care.
Design/methodology/approach
A phenomenological research approach was used as the authors sought to build an understanding of the social interactions between family and their lifeworld.
Findings
This study extends theory on the relationship between the elderly parent and their family and explores through practice theory how families performed their love, how altered routines and long standing rituals provided structure to the elderly relatives and how care practices were negotiated as the elderly relatives transitioned from independence to dependence and towards care. A theoretical framework is introduced that provides guidance for the transition stages and the areas for negotiation.
Research limitations/implications
This research has implications for food manufacturers and marketers, as the demand for healthy food for the elderly is made more widely available, healthy and easy to prepare. The limitations of the research are due to the sample located in East Yorkshire only.
Practical implications
This research has implications for brand managers of food manufacturers and supermarkets that need to create product lines that target this segment by producing healthy, convenience food.
Social implications
It is also important for health and social care policy as the authors seek to understand the role of food, family and community and how policy can be devised to provide stability in this transitional and uncertain lifestage.
Originality/value
This research extends the body of literature on food and the family by focussing on the elderly cared for and their family. The authors show how food can be construed as loving care, and using practice theory, a theoretical framework is developed that can explain the transitions and how the family negotiates the stages from independence to dependence
Physical and emotional nourishment: Food as the embodied component of loving care of elderly family relatives
Purpose
This purpose of this study is to examine the fluidity of family life which continues to attract attention. This is increasingly significant for the intergenerational relationship between adult children and their elderly parents. Using practice theory, the aims are to understand the role of food in elderly families and explore how family practices are maintained when elderly transition into care.
Design/methodology/approach
A phenomenological research approach was used as the authors sought to build an understanding of the social interactions between family and their lifeworld.
Findings
This study extends theory on the relationship between the elderly parent and their family and explores through practice theory how families performed their love, how altered routines and long standing rituals provided structure to the elderly relatives and how care practices were negotiated as the elderly relatives transitioned from independence to dependence and towards care. A theoretical framework is introduced that provides guidance for the transition stages and the areas for negotiation.
Research limitations/implications
This research has implications for food manufacturers and marketers, as the demand for healthy food for the elderly is made more widely available, healthy and easy to prepare. The limitations of the research are due to the sample located in East Yorkshire only.
Practical implications
This research has implications for brand managers of food manufacturers and supermarkets that need to create product lines that target this segment by producing healthy, convenience food.
Social implications
It is also important for health and social care policy as the authors seek to understand the role of food, family and community and how policy can be devised to provide stability in this transitional and uncertain lifestage.
Originality/value
This research extends the body of literature on food and the family by focussing on the elderly cared for and their family. The authors show how food can be construed as loving care, and using practice theory, a theoretical framework is developed that can explain the transitions and how the family negotiates the stages from independence to dependence
Recommended from our members
Organizational Discourse: Domains, Debates, and Directions
Interest in the analysis of organizational discourse has expanded rapidly over the last two decades. In this article, we reflect critically on organizational discourse analysis as an approach to the study of organizations and management, highlighting both its strengths and areas of challenge. We begin with an explanation of the nature of organizational discourse analysis and outline some of the more significant contributions made to date. We then discuss existing classifications of approaches to the study of organizational discourse and suggest that they fall into two main categories: classifications by level of analysis and classifications by type of method. We argue that both of these approaches are inherently problematic and present an alternative way to understand the varieties of approaches to the analysis of organizational discourse based on within domain and across domain characterizations. We conclude with a discussion of the challenges that remain in the development of organizational discourse as an area of study and point to some of the opportunities for important and unique contributions to our understanding of organizations and management that this family of methods brings. © 2012 Copyright Academy of Management
- …