764 research outputs found
Detecting the Cold Spot as a Void with the Non-Diagonal Two-Point Function
The anomaly in the Cosmic Microwave Background known as the "Cold Spot" could
be due to the existence of an anomalously large spherical (few hundreds Mpc/h
radius) underdense region, called a "Void" for short. Such a structure would
have an impact on the CMB also at high multipoles l through Lensing. This would
then represent a unique signature of a Void. Modeling such an underdensity with
an LTB metric, we show that the Lensing effect leads to a large signal in the
non-diagonal two-point function, centered in the direction of the Cold Spot,
such that the Planck satellite will be able to confirm or rule out the Void
explanation for the Cold Spot, for any Void radius with a Signal-to-Noise ratio
of at least O(10).Comment: v1: 6 pages, 2 figures; v2: 6 pages, 2 figures, text improved, to
appear on JCA
Assessment of Emotional Experience and Emotional Recognition in Complicated Grief
There is substantial evidence of bias in the processing of emotion in people with complicated grief (CG). Previous studies have tended to assess the expression of emotion in CG, but other aspects of emotion (mainly emotion recognition, and the subjective aspects of emotion) have not been addressed, despite their importance for practicing clinicians. A quasi-experimental design with two matched groups (Complicated Grief, N D 24 and Non-Complicated Grief, N D 20) was carried out. The Facial Expression of Emotion Test (emotion recognition), a set of pictures from the International Affective Picture System (subjective experience of emotion) and the Symptom Checklist 90 Revised (psychopathology) were employed. The CG group showed lower scores on the dimension of valence for specific conditions on the IAPS, related to the subjective experience of emotion. In addition, they presented higher values of psychopathology. In contrast, statistically significant results were not found for the recognition of emotion. In conclusion, from a neuropsychological point of view, the subjective aspects of emotion and psychopathology seem central in explaining the experience of those with CG. These results are clinically significant for psychotherapists and psychoanalysts working in the field of grief and loss
Diversidad y paradigmas de empresa: un nuevo enfoque
Después de hacer un repaso por la literatura académica sobre gestión de la diversidad desde los años noventa hasta la fecha, este artículo propone que el objetivo de la gestión de la diversidad debe ser la unidad de la organización, no el simple incremento de la misma. Para lograr este objetivo se necesitan dos cosas: fomentar la motivación trascendente de los directivos y colaboradores y desarrollar competencias de liderazgo inter e intrapersonales. Para fundamentar estas propuestas se introduce el modelo conocido como Octógono Empresarial, basado en la teoría de Pérez López (1992). A lo largo de la argumentación se establecen cinco principios generales para la gestión de la diversidad.-----After reviewing the academic literature from the Nineties to today on diversity management, this paper suggests that the objective of diversity management must be the unity of the organization, not simply the growth of the same. To achieve this goal, two things are needed: first, the promotion of altruistic motivation of managers and employees, and second, the development of interand intrapersonal competencies. In support of these proposals, the anthropological paradigm of the company, based on the theory of Pérez López (1992), will be introduced. Throughout the argument five principles for diversity management will be set out
CP-odd invariants in models with several Higgs doublets
We present CP-odd Higgs-basis invariants, which can be used to signal CP
violation in a multi-Higgs system, written in an arbitrary Higgs basis. It is
shown through specific examples how these CP-odd invariants can also be useful
to determine the character of CP breaking (i.e. whether it is hard or soft CP
breaking) in a given Higgs Lagrangian. We analyse in detail the cases of two
and three Higgs doublets
A Theory of a Spot
We present a simple inflationary scenario that can produce arbitrarily large
spherical underdense or overdense regions embedded in a standard Lambda cold
dark matter paradigm, which we refer to as bubbles. We analyze the effect such
bubbles would have on the Cosmic Microwave Background (CMB). For super-horizon
sized bubble in the vicinity of the last scattering surface, a signal is
imprinted onto CMB via a combination of Sach-Wolfe and an early integrated
Sach-Wolfe (ISW) effects. Smaller, sub-horizon sized bubbles at lower redshifts
(during matter domination and later) can imprint secondary anisotropies on the
CMB via Rees-Sciama, late-time ISW and Ostriker-Vishniac effects. Our scenario,
and arguably most similar inflationary models, produce bubbles which are
over/underdense in potential: in density such bubbles are characterized by
having a distinct wall with the interior staying at the cosmic mean density. We
show that such models can potentially, with only moderate fine tuning, explain
the \emph{cold spot}, a non-Gaussian feature identified in the Wilkinson
Microwave Anisotropy Probe (WMAP) data by several authors. However, more
detailed comparisons with current and future CMB data are necessary to confirm
(or rule out) this scenario.Comment: 19 pages, 19 figures, added references and explanations, JCAP in
pres
Kalb-Ramond excitations in a thick-brane scenario with dilaton
We compute the full spectrum and eigenstates of the Kalb-Ramond field in a
warped non-compact Randall-Sundrum -type five-dimensional spacetime in which
the ordinary four-dimensional braneworld is represented by a sine-Gordon
soliton. This 3-brane solution is fully consistent with both the warped
gravitational field and bulk dilaton configurations. In such a background we
embed a bulk antisymmetric tensor field and obtain, after reduction, an
infinite tower of normalizable Kaluza-Klein massive components along with a
zero-mode. The low lying mass eigenstates of the Kalb-Ramond field may be
related to the axion pseudoscalar. This yields phenomenological implications on
the space of parameters, particularly on the dilaton coupling constant. Both
analytical and numerical results are given.Comment: 10 pages, 13 figures, and 2 tables. Final version to appear in The
European Physical Journal
Theory and phenomenology of two-Higgs-doublet models
We discuss theoretical and phenomenological aspects of two-Higgs-doublet
extensions of the Standard Model. In general, these extensions have scalar
mediated flavour changing neutral currents which are strongly constrained by
experiment. Various strategies are discussed to control these flavour changing
scalar currents and their phenomenological consequences are analysed. In
particular, scenarios with natural flavour conservation are investigated,
including the so-called type I and type II models as well as lepton-specific
and inert models. Type III models are then discussed, where scalar flavour
changing neutral currents are present at tree level, but are suppressed by
either specific ansatze for the Yukawa couplings or by the introduction of
family symmetries. We also consider the phenomenology of charged scalars in
these models. Next we turn to the role of symmetries in the scalar sector. We
discuss the six symmetry-constrained scalar potentials and their extension into
the fermion sector. The vacuum structure of the scalar potential is analysed,
including a study of the vacuum stability conditions on the potential and its
renormalization-group improvement. The stability of the tree level minimum of
the scalar potential in connection with electric charge conservation and its
behaviour under CP is analysed. The question of CP violation is addressed in
detail, including the cases of explicit CP violation and spontaneous CP
violation. We present a detailed study of weak basis invariants which are odd
under CP. A careful study of spontaneous CP violation is presented, including
an analysis of the conditions which have to be satisfied in order for a vacuum
to violate CP. We present minimal models of CP violation where the vacuum phase
is sufficient to generate a complex CKM matrix, which is at present a
requirement for any realistic model of spontaneous CP violation.Comment: v3: 180 pages, 506 references, new chapter 7 with recent LHC results;
referee comments taken into account; submitted to Physics Report
Measurement of W Polarisation at LEP
The three different helicity states of W bosons produced in the reaction e+
e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W
decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to
measure the polarisation of W bosons, and its dependence on the W boson
production angle. The fraction of longitudinally polarised W bosons is measured
to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and
the second systematic, in agreement with the Standard Model expectation
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