6,806 research outputs found
Looking for in non-minimal Universal Extra Dimensional model
Non-vanishing boundary localised terms significantly modify the mass spectrum
and various interactions among the Kaluza-Klein excited states of 5-Dimensional
Universal Extra Dimensional scenario. In this scenario we compute the
contributions of Kaluza-Klein excitations of gauge bosons and third generation
quarks for the decay process incorporating
next-to-leading order QCD corrections. We estimate branching ratio as well as
Forward Backward asymmetry associated with this decay process. Considering the
constraints from some other observables and electroweak precision
data we show that significant amount of parameter space of this scenario has
been able to explain the observed experimental data for this decay process.
From our analysis we put lower limit on the size of the extra dimension by
comparing our theoretical prediction for branching ratio with the corresponding
experimental data. Depending on the values of free parameters of the present
scenario, lower limit on the inverse of the radius of compactification
() can be as high as GeV. {Even this value could slightly be
higher if we project the upcoming measurement by Belle II experiment.}
Unfortunately, the Forward Backward asymmetry of this decay process would not
provide any significant limit on in the present model.Comment: 47 pages, 6 Figures, 3 Tables, typos corrected, references added,
remarks added, version accepted in Physical Review
Representations of Time Coordinates in FITS
In a series of three previous papers, formulation and specifics of the
representation of World Coordinate Transformations in FITS data have been
presented. This fourth paper deals with encoding time. Time on all scales and
precisions known in astronomical datasets is to be described in an unambiguous,
complete, and self-consistent manner. Employing the well--established World
Coordinate System (WCS) framework, and maintaining compatibility with the FITS
conventions that are currently in use to specify time, the standard is extended
to describe rigorously the time coordinate. World coordinate functions are
defined for temporal axes sampled linearly and as specified by a lookup table.
The resulting standard is consistent with the existing FITS WCS standards and
specifies a metadata set that achieves the aims enunciated above.Comment: FITS WCS Paper IV: Time. 27 pages, 11 table
Localization to Enhance Security and Services in Wi-Fi Networks under Privacy Constraints
Developments of seamless mobile services are faced with two broad challenges, systems security and user privacy - access to wireless systems is highly insecure due to the lack of physical boundaries and, secondly, location based services (LBS) could be used to extract highly sensitive user information. In this paper, we describe our work on developing systems which exploit location information to enhance security and services under privacy constraints. We describe two complimentary methods which we have developed to track node location information within production University Campus Networks comprising of large numbers of users. The location data is used to enhance security and services. Specifically, we describe a method for creating geographic firewalls which allows us to restrict and enhance services to individual users within a specific containment area regardless of physical association. We also report our work on LBS development to provide visualization of spatio-temporal node distribution under privacy considerations
Construction of a Pragmatic Base Line for Journal Classifications and Maps Based on Aggregated Journal-Journal Citation Relations
A number of journal classification systems have been developed in
bibliometrics since the launch of the Citation Indices by the Institute of
Scientific Information (ISI) in the 1960s. These systems are used to normalize
citation counts with respect to field-specific citation patterns. The best
known system is the so-called "Web-of-Science Subject Categories" (WCs). In
other systems papers are classified by algorithmic solutions. Using the Journal
Citation Reports 2014 of the Science Citation Index and the Social Science
Citation Index (n of journals = 11,149), we examine options for developing a
new system based on journal classifications into subject categories using
aggregated journal-journal citation data. Combining routines in VOSviewer and
Pajek, a tree-like classification is developed. At each level one can generate
a map of science for all the journals subsumed under a category. Nine major
fields are distinguished at the top level. Further decomposition of the social
sciences is pursued for the sake of example with a focus on journals in
information science (LIS) and science studies (STS). The new classification
system improves on alternative options by avoiding the problem of randomness in
each run that has made algorithmic solutions hitherto irreproducible.
Limitations of the new system are discussed (e.g. the classification of
multi-disciplinary journals). The system's usefulness for field-normalization
in bibliometrics should be explored in future studies.Comment: accepted for publication in the Journal of Informetrics, 20 July 201
Geometric flows in Horava-Lifshitz gravity
We consider instanton solutions of Euclidean Horava-Lifshitz gravity in four
dimensions satisfying the detailed balance condition. They are described by
geometric flows in three dimensions driven by certain combinations of the
Cotton and Ricci tensors as well as the cosmological-constant term. The
deformation curvature terms can have competing behavior leading to a variety of
fixed points. The instantons interpolate between any two fixed points, which
are vacua of topologically massive gravity with Lambda > 0, and their action is
finite. Special emphasis is placed on configurations with SU(2) isometry
associated with homogeneous but generally non-isotropic Bianchi IX model
geometries. In this case, the combined Ricci-Cotton flow reduces to an
autonomous system of ordinary differential equations whose properties are
studied in detail for different couplings. The occurrence and stability of
isotropic and anisotropic fixed points are investigated analytically and some
exact solutions are obtained. The corresponding instantons are classified and
they are all globally R x S^3 and complete spaces. Generalizations to
higher-dimensional gravities are also briefly discussed.Comment: 67 pages, 16 figures; more solutions found, 1 extra figure, 1 more
reference added in v2; minor typos corrected in v3 (to appear in JHEP); an
acknowledgement added in v
Lower Mekong Portfolio: Interim Evaluation
This report summarizes a portfolio evaluation of the MacArthur Foundation's conservation investments in the Lower Mekong region since 2011. It is explicitly a portfolio-level evaluation, focusing on common themes rather than individual grants. The evaluation involved understanding the portfolio context through reviewing relevant documents and speaking with donor partners; gathering data from MacArthur grantees; calibrating initial evaluation findings through consultations with independent regional experts and donor partner grantees; improving future evaluation ability by cooperating with NatureServe to improve the Lower Mekong Dashboard; and presenting results in this evaluation report and to MacArthur directly
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