8,234 research outputs found
Half-BPS M2-brane orbifolds
Smooth Freund-Rubin backgrounds of eleven-dimensional supergravity of the
form AdS_4 x X^7 and preserving at least half of the supersymmetry have been
recently classified. Requiring that amount of supersymmetry forces X to be a
spherical space form, whence isometric to the quotient of the round 7-sphere by
a freely-acting finite subgroup of SO(8). The classification is given in terms
of ADE subgroups of the quaternions embedded in SO(8) as the graph of an
automorphism. In this paper we extend this classification by dropping the
requirement that the background be smooth, so that X is now allowed to be an
orbifold of the round 7-sphere. We find that if the background preserves more
than half of the supersymmetry, then it is automatically smooth in accordance
with the homogeneity conjecture, but that there are many half-BPS orbifolds,
most of them new. The classification is now given in terms of pairs of ADE
subgroups of quaternions fibred over the same finite group. We classify such
subgroups and then describe the resulting orbifolds in terms of iterated
quotients. In most cases the resulting orbifold can be described as a sequence
of cyclic quotients.Comment: 51 pages; v3: substantial revision (20% longer): we had missed some
cases, but the paper now includes a check of our results via comparison with
extant classification of finite subgroups of SO(4
Half-BPS quotients in M-theory: ADE with a twist
We classify Freund-Rubin backgrounds of eleven-dimensional supergravity of
the form AdS_4 x X^7 which are at least half BPS; equivalently, smooth
quotients of the round 7-sphere by finite subgroups of SO(8) which admit an
(N>3)-dimensional subspace of Killing spinors. The classification is given in
terms of pairs consisting of an ADE subgroup of SU(2) and an automorphism
defining its embedding in SO(8). In particular we find novel half-BPS quotients
associated with the subgroups of type D_n (for n>5), E_7 and E_8 and their
outer automorphisms.Comment: 16 pages; V2: notational inconsistencies addressed, final version to
be published in JHE
Metric Lie 3-algebras in Bagger-Lambert theory
We recast physical properties of the Bagger-Lambert theory, such as
shift-symmetry and decoupling of ghosts, the absence of scale and parity
invariance, in Lie 3-algebraic terms, thus motivating the study of metric Lie
3-algebras and their Lie algebras of derivations. We prove a structure theorem
for metric Lie 3-algebras in arbitrary signature showing that they can be
constructed out of the simple and one-dimensional Lie 3-algebras iterating two
constructions: orthogonal direct sum and a new construction called a double
extension, by analogy with the similar construction for Lie algebras. We
classify metric Lie 3-algebras of signature (2,p) and study their Lie algebras
of derivations, including those which preserve the conformal class of the inner
product. We revisit the 3-algebraic criteria spelt out at the start of the
paper and select those algebras with signature (2,p) which satisfy them, as
well as indicate the construction of more general metric Lie 3-algebras
satisfying the ghost-decoupling criterion.Comment: 38 page
On the Lie-algebraic origin of metric 3-algebras
Since the pioneering work of Bagger-Lambert and Gustavsson, there has been a
proliferation of three-dimensional superconformal Chern-Simons theories whose
main ingredient is a metric 3-algebra. On the other hand, many of these
theories have been shown to allow for a reformulation in terms of standard
gauge theory coupled to matter, where the 3-algebra does not appear explicitly.
In this paper we reconcile these two sets of results by pointing out the
Lie-algebraic origin of some metric 3-algebras, including those which have
already appeared in three-dimensional superconformal Chern-Simons theories.
More precisely, we show that the real 3-algebras of Cherkis-Saemann, which
include the metric Lie 3-algebras as a special case, and the hermitian
3-algebras of Bagger-Lambert can be constructed from pairs consisting of a
metric real Lie algebra and a faithful (real or complex, respectively) unitary
representation. This construction generalises and we will see how to construct
many kinds of metric 3-algebras from pairs consisting of a real metric Lie
algebra and a faithful (real, complex or quaternionic) unitary representation.
In the real case, these 3-algebras are precisely the Cherkis-Saemann algebras,
which are then completely characterised in terms of this data. In the complex
and quaternionic cases, they constitute generalisations of the Bagger-Lambert
hermitian 3-algebras and anti-Lie triple systems, respectively, which underlie
N=6 and N=5 superconformal Chern-Simons theories, respectively. In the process
we rederive the relation between certain types of complex 3-algebras and metric
Lie superalgebras.Comment: 29 pages (v4: really final version to appear in CMP. Example 7 has
been improved.
Gauging of Nonlinearly Realized Symmetries
A representation of a subgroup H of a finite-dimensional group G can be used
to induce a nonlinear realization of G. If the nonlinearly realized symmetry is
gauged, then the BRST charge can be related by a similarity transformation to
the BRST charge for the gauged linear realization of H (plus a cohomologically
trivial piece). It is shown that the relation between the two BRST charges is a
reflection of the fact that they can be interpreted geometrically as
expressions for the exterior derivative on G relative to two different bases,
and an explicit expression for the generator of the similarity transformation
is obtained. This result is applied in an infinite-dimensional setting, where
it yields the similarity transformation used by Ishikawa and Kato to prove the
equivalence of the Berkovits-Vafa superstring with the underlying bosonic
string theory.Comment: 14 pages, LATEX documen
Tratado espiritual, en el qual se contienen dos obras, la primera trata de la venta de Judas quando vendió a nuestro Redemptor Jesu Christo y de como ay muchos Judas que cada dÃa le venden ; y la otra obra, el negamiento y llanto de Sant Pedro, sobre aquella glosa que dize, Quien es Dios y quien soy yo
Copia digital. Valladolid : Junta de Castilla y León. ConsejerÃa de Cultura y Turismo, 2009-201
Towards an evaluation model of emotional competencies in nurse students
En los últimos años múltiples estudios han demostrado la importancia de la inteligencia emocional para el desarrollo profesional óptimo de los alumnos de enfermerÃa. Este trabajo nace como respuesta ante la necesidad de una herramienta que permita medir de forma clara y objetiva las competencias emocionales de los estudiantes de enfermerÃa. Tras haber realizado una revisión bibliográfica de artÃculos cientÃficos y bibliotecas online entre las que destacan Pubmed, Medline Plus, ENFISPO y SCIELO en la que se ha tenido en cuenta la fecha de publicación y aquellos con mayor número de citaciones. Se ha analizado los diferentes métodos para evaluar este factor, tales como las medidas de autoinforme, las medidas de habilidad o el método ECOE, concluimos que la información que aportan, aunque pertinente podrÃa estar más adaptada al contexto académico. En el presente trabajo, se propone una nueva herramienta que pretende reunir las ventajas de los tres anteriores y completar la información que aportan a través de un rol-playing en el que se evaluará al alumno mediante una rúbrica sencilla, de forma que cualquiera pueda emplearla sin formación especÃfica. De este modo, el alumno identificará las áreas de mejora en su desempeño y los aspectos correctos de su práctica, de manera que esta rúbrica, no solamente sirva como un instrumento de evaluación sino que además pueda ser útil para el desarrollo de las competencias profesionales del alumno de enfermerÃaDuring the past years, multiple studies have demonstrated the importance of emotional intelligence for the positive professional development of nurse students. This document has been created due to the need of an instrument that can allow us to measure clearly and objectively the emotional competencies of the nurse students. After having done a bibliographical review of scientific articles and libraries online such as Pubmed, Medline Plus, ENFISPO and SCIELO in which we have taken into account the publication date and the number of citations, we have analysed the different existing methods to evaluate this factor, such as self-report- measures, the ability measures or the ECOE method, we conclude that the information they provide, even though it is pertinent, could be better adapted to the academic environment. In this project, we suggest a new tool that will include the advantages of the three mentioned above and complete the information with the role-playing that will evaluate the student according to a simple rubric, this way anyone can use it without previous specialized knowledge. Consequently, the student will be able to identify improvements in their performance and recognize the correct aspects of their enactment, as a result of this, apart from using it as a tool to evaluate; it can be considered for the personal development of the nurse student.Fac. de EnfermerÃa, Fisioterapia y PodologÃaTRUEsubmitte
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