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Designer de Sitter Spacetimes  [PDF]
K. Schleich,D. M. Witt
Physics , 2008, DOI: 10.1139/P07-191
Abstract: Recent observations in cosmology indicate an accelerating expansion of the universe postulated to arise from some form of dark energy, the paradigm being positive cosmological constant. De Sitter spacetime is the well-known isotropic solution to the Einstein equations with cosmological constant. However, as discussed here, it is not the most general, locally isotropic solution. One can construct an infinite family of such solutions, designer de Sitter spacetimes, which are everywhere locally isometric to a region of de Sitter spacetime. However, the global dynamics of these designer cosmologies is very different than that of de Sitter spacetime itself. The construction and dynamics of these designer de Sitter spacetimes is detailed along with some comments about their implications for the structure of our universe.
Stability in Designer Gravity  [PDF]
Thomas Hertog,Stefan Hollands
Physics , 2005, DOI: 10.1088/0264-9381/22/24/007
Abstract: We study the stability of designer gravity theories, in which one considers gravity coupled to a tachyonic scalar with anti-de Sitter boundary conditions defined by a smooth function W. We construct Hamiltonian generators of the asymptotic symmetries using the covariant phase space method of Wald et al.and find they differ from the spinor charges except when W=0. The positivity of the spinor charge is used to establish a lower bound on the conserved energy of any solution that satisfies boundary conditions for which $W$ has a global minimum. A large class of designer gravity theories therefore have a stable ground state, which the AdS/CFT correspondence indicates should be the lowest energy soliton. We make progress towards proving this, by showing that minimum energy solutions are static. The generalization of our results to designer gravity theories in higher dimensions involving several tachyonic scalars is discussed.
Energy Bounds in Designer Gravity  [PDF]
Aaron J. Amsel,Donald Marolf
Physics , 2006, DOI: 10.1103/PhysRevD.75.029901
Abstract: We consider asymptotically anti-de Sitter gravity coupled to tachyonic scalar fields with mass at or slightly above the Breitenlohner-Freedman bound in d greater than or equal to 4 spacetime dimensions. The boundary conditions in these ``designer gravity'' theories are defined in terms of an arbitrary function W. We give a general argument that the Hamiltonian generators of asymptotic symmetries for such systems will be finite, and proceed to construct these generators using the covariant phase space method. The direct calculation confirms that the generators are finite and shows that they take the form of the pure gravity result plus additional contributions from the scalar fields. By comparing the generators to the spinor charge, we derive a lower bound on the gravitational energy when i) W has a global minimum, ii) the Breitenlohner-Freedman bound is not saturated, and iii) the scalar potential V admits a certain type of "superpotential."
NSUSY fits  [PDF]
José R. Espinosa,Christophe Grojean,Verónica Sanz,Michael Trott
Physics , 2012, DOI: 10.1007/JHEP12(2012)077
Abstract: We perform a global fit to Higgs signal-strength data in the context of light stops in Natural SUSY. In this case, the Wilson coefficients of the higher dimensional operators mediating g g -> h and h -> \gamma \gamma, given by c_g, c_\gamma, are related by c_g = 3 (1 + 3 \alpha_s/(2 \pi)) c_\gamma/8. We examine this predictive scenario in detail, combining Higgs signal-strength constraints with recent precision measurements of m_W, b-> s \gamma constraints and direct collider bounds on weak scale SUSY, finding regions of parameter space that are consistent with all of these constraints. However it is challenging for the allowed parameter space to reproduce the observed Higgs mass value with sub-TeV stops. We discuss some of the direct stop discovery prospects and show how global Higgs fits can be used to exclude light stop parameter space difficult to probe by direct collider searches. We determine the current status of such indirect exclusions and estimate their reach by the end of the 8 TeV LHC run.
Global Fits of the CKM Matrix  [PDF]
G. Eigen,G. P. Dubois-Felsmann,D. G. Hitlin,F. C. Porter
Physics , 2003, DOI: 10.1140/epjcd/s2003-03-705-8
Abstract: We report upon the present status of global fits to Cabibbo-Kobayashi-Maskawa matrix.
Hidden risks for pneumonia in Malawi
DG Fullerton, SB Gordon
Malawi Medical Journal , 2003,
Abstract: Domestic smoke exposure and early HIV infection are critical but unseen risk factors for pneumonia. This paper reviews how recent research in Malawi and elsewhere contributes to an understanding of the possible immunological mechanisms underlying these risks. [Malawi Med J, Vol.15(2) 2003: 68-71]
Invariant Recognition of Rectangular Biscuits with Fuzzy Moment Descriptors, Flawed Pieces Detection  [PDF]
Pulivarthi Srinivasa Rao, Sheli Sinha Chaudhuri,& Romesh Laishram
International Journal of Image Processing , 2010,
Abstract: In this paper a new approach for invariant recognition of broken rectangularbiscuits is proposed using fuzzy membership-distance products, called fuzzymoment descriptors. The existing methods for recognition of flawed rectangularbiscuits are mostly based on Hough transform. However these methods areprone to error due to noise and/or variation in illumination. Fuzzy momentdescriptors are less sensitive to noise thus making it an effective approach andinvariant to the above stray external disturbances. Further, the normalization andsorting of the moment vectors make it a size and rotation invariant recognitionprocess .In earlier studies fuzzy moment descriptors has successfully beenapplied in image matching problem. In this paper the algorithm is applied inrecognition of flawed and non-flawed rectangular biscuits. In general theproposed algorithm has potential applications in industrial quality control.
Experience of Conducting Objective Structured Clinical Evaluation (OSCE) in Malawi  [PDF]
Tiwonge Ethel Mbeya Munkhondya, Gladys Msiska, Evelyn Chilemba, Maureen Daisy Majamanda
Open Journal of Nursing (OJN) , 2014, DOI: 10.4236/ojn.2014.410075
Abstract: In Malawi various nursing educational institutions have increased the enrollment of nursing students in order to respond to the rampant nursing shortage prevalent in the Malawian clinical settings. With this increase in intake, nurse educators are met with so many questions as to whether the nurses being trained are competent and fit for practice. To ensure that these nurses have appropriate competences, Objective Structured Clinical Evaluation (OSCE) has been embraced as a key strategy to evaluate student’s competence. The paper describes the lessons learnt from conducting OSCE to undergraduate student nurses at Kamuzu College of Nursing in Malawi. The paper considers the background and context of the school, the preparation of students, the formulation of OSCE tasks, recruitment of examiner and simulated patients and the evaluation of the OSCE. The paper concludes that OSCE can be a worthwhile valid strategy of teaching and assessing nursing students as long as it is properly designed. Nonetheless, profound commitment of all stakeholders involved is very vital.
Fits to Light WIMPs  [PDF]
Graciela B. Gelmini
Physics , 2012,
Abstract: We review fits to "light WIMPs" since the region was first mentioned relative to the DAMA collaboration data in 2003 to the present, analyzing the compatibility of potential signals and bounds in this region. We include dark halo independent data comparisons.
Representations of celestial coordinates in FITS  [PDF]
Mark R. Calabretta,Eric W. Greisen
Physics , 2002, DOI: 10.1051/0004-6361:20021327
Abstract: In Paper I, Greisen & Calabretta (2002) describe a generalized method for assigning physical coordinates to FITS image pixels. This paper implements this method for all spherical map projections likely to be of interest in astronomy. The new methods encompass existing informal FITS spherical coordinate conventions and translations from them are described. Detailed examples of header interpretation and construction are given.
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