2,280 research outputs found
Higher Spin Black Holes from CFT
Higher spin gravity in three dimensions has explicit black holes solutions,
carrying higher spin charge. We compute the free energy of a charged black hole
from the holographic dual, a 2d CFT with extended conformal symmetry, and find
exact agreement with the bulk thermodynamics. In the CFT, higher spin
corrections to the free energy can be calculated at high temperature from
correlation functions of W-algebra currents.Comment: 24 pages; v2 reference adde
A de Sitter Hoedown
Rotating black holes in de Sitter space are known to have interesting limits
where the temperatures of the black hole and cosmological horizon are equal. We
give a complete description of the thermal phase structure of all allowed
rotating black hole configurations. Only one configuration, the rotating Nariai
limit, has the black hole and cosmological horizons both in thermal and
rotational equilibrium, in that both the temperatures and angular velocities of
the two horizons coincide. The thermal evolution of the spacetime is shown to
lead to the pure de Sitter spacetime, which is the most entropic configuration.
We then provide a comprehensive study of the wave equation for a massless
scalar in the rotating Nariai geometry. The absorption cross section at the
black hole horizon is computed and a condition is found for when the scattering
becomes superradiant. The boundary-to-boundary correlators at finite
temperature are computed at future infinity. The quasinormal modes are obtained
in explicit form. Finally, we obtain an expression for the expectation value of
the number of particles produced at future infinity starting from a vacuum
state with no incoming particles at past infinity. Some of our results are used
to provide further evidence for a recent holographic proposal between the
rotating Nariai geometry and a two-dimensional conformal field theory.Comment: 35 + 1 pages, 9 figures; v3: typos correcte
Hidden conformal symmetry of extreme and non-extreme Einstein-Maxwell-Dilaton-Axion black holes
The hidden conformal symmetry of extreme and non-extreme
Einstein-Maxwell-Dilaton-Axion (EMDA) black holes is addressed in this paper.
For the non-extreme one, employing the wave equation of massless scalars, the
conformal symmetry with left temperature and right
temperature in the near region is
found. The conformal symmetry is spontaneously broken due to the periodicity of
the azimuthal angle. The microscopic entropy is derived by the Cardy formula
and is fully in consistence with the Bekenstein-Hawking area-entropy law. The
absorption cross section in the near region is calculated and exactly equals
that in a 2D CFT. For the extreme case, by redefining the conformal
coordinates, the duality between the solution space and CFT is studied. The
microscopic entropy is found to exactly agree with the area-entropy law.Comment: V3, typos corrected, version to appear in JHE
Higher spin AdS_3 supergravity and its dual CFT
Vasiliev's higher spin supergravity theory on three dimensional anti-de
Sitter space is studied and, in particular, the partition function is computed
at one loop level. The dual conformal field theory is proposed to be the
N=(2,2) CP^N Kazama-Suzuki model in two dimensions. The proposal is based on
symmetry considerations and comparison of the bulk partition function with the
conformal field theory. Our findings suggest that the theory is strong-weak
self-dual.Comment: 36 page
DE HIPERFRECUENTADORA A ABUELA ESCLAVA. Estudio de un caso de sobrecarga del cuidador desde el Síndrome de la Abuela Esclava de Guijarro Morales.
The study aims to determine the profile of a high-frequency user of the hospital emergency department who made 299 visits in 3 years, analyzing the profile through the theoretical framework of the slave grandmother syndrome of Guijarro Morales.We conclude from analysis of the demand profile (retrospective epidemiological study) and through semi-structured interviews (qualitative descriptive study) that the patient suffers from the slave grandmother syndrome. Finally we reflect on the social implications of the syndrome.El trabajo tiene como objetivo conocer el perfil de una paciente hiperfrecuentadora que acude al servicio de urgencias hospitalario 299 ocasiones en 3 años y analizarlo a través del marco teórico del síndrome de la abuela esclava de Guijarro Morales. Concluimos, analizando su perfil de demanda (estudio epidemiológico restrospectivo) y a través de una entrevista semiestructurada (estudio descriptivo cualitativo), que la paciente sufre el síndrome de la abuela esclava. Por último realizamos una reflexión sobre las implicaciones sociales del síndrome
Pulmonary changes on HRCT scans in nonsmoking females with COPD due to wood smoke exposure
OBJECTIVE: To identify and characterize alterations seen on HRCT scans in nonsmoking females with COPD due to wood smoke exposure. METHODS: We evaluated 42 nonsmoking females diagnosed with wood smokerelated COPD and 31 nonsmoking controls with no history of wood smoke exposure or pulmonary disease. The participants completed a questionnaire regarding demographic data, symptoms, and environmental exposure. All of the participants underwent spirometry and HRCT of the chest. The COPD and control groups were adjusted for age (23 patients each). RESULTS: Most of the patients in the study group were diagnosed with mild to moderate COPD (83.3%). The most common findings on HRCT scans in the COPD group were bronchial wall thickening, bronchiectasis, mosaic perfusion pattern, parenchymal bands, tree-in-bud pattern, and laminar atelectasis (p < 0.001 vs. the control group for all). The alterations were generally mild and not extensive. There was a positive association between bronchial wall thickening and hour-years of wood smoke exposure. Centrilobular emphysema was uncommon, and its occurrence did not differ between the groups (p = 0.232). CONCLUSIONS: Wood smoke exposure causes predominantly bronchial changes, which can be detected by HRCT, even in patients with mild COPD.OBJETIVO: Identificar e caracterizar alterações na TCAR de tórax em mulheres com DPOC causada por exposiçãoà fumaça da combustão de lenha. MÉTODOS: Foram selecionadas 42 pacientes com DPOC relacionada à exposição à fumaça de lenha, não fumantes, e 31 mulheres não fumantes e sem história de exposição à fumaça de lenha ou de doença pulmonar. Empregou-se um questionário para a obtenção de dados demográficos e informações sobre sintomas e exposições ambientais. Todas as participantes realizaram espirometria e TCAR de tórax. Os grupos DPOC e controle foram ajustados por idade, com 23 pacientes cada. RESULTADOS: A maioria das pacientes do grupo de estudo apresentava DPOC de leve a moderado (83,3%). Os achados de TCAR mais frequentes no grupo DPOC foram espessamento das paredes brônquicas, bronquiectasias, perfusão em mosaico, bandas parenquimatosas, padrão de árvore em brotamento e atelectasias laminares (p < 0,001 para todos na comparação com o grupo controle). As alterações, em geral, foram leves e de pequena extensão. Houve uma associação positiva entre espessamento das paredes brônquicas e duração da exposição à fumaça de lenha em horas-ano. O achado de enfisema centrolobular foi infrequente e não diferiu entre os grupos (p = 0,232). CONCLUSÕES: A exposição à fumaça de lenha provoca alterações predominantemente brônquicas, que podem ser detectadas por TCAR, mesmo nos casos de DPOC leve.Universidade Federal de Goiás Faculdade de MedicinaUniversidade Federal de Goiás Faculdade de EnfermagemUniversidade Federal de Goiás Faculdade de Medicina Hospital das ClínicasUniversidade Federal de Goiás Faculdade de Medicina Departamento de Imagenologia e PatologiaClínica Multimagem DiagnósticosUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL
Light States in Chern-Simons Theory Coupled to Fundamental Matter
Motivated by developments in vectorlike holography, we study SU(N)
Chern-Simons theory coupled to matter fields in the fundamental representation
on various spatial manifolds. On the spatial torus T^2, we find light states at
small `t Hooft coupling \lambda=N/k, where k is the Chern-Simons level, taken
to be large. In the free scalar theory the gaps are of order \sqrt {\lambda}/N
and in the critical scalar theory and the free fermion theory they are of order
\lambda/N. The entropy of these states grows like N Log(k). We briefly consider
spatial surfaces of higher genus. Based on results from pure Chern-Simons
theory, it appears that there are light states with entropy that grows even
faster, like N^2 Log(k). This is consistent with the log of the partition
function on the three sphere S^3, which also behaves like N^2 Log(k). These
light states require bulk dynamics beyond standard Vasiliev higher spin gravity
to explain them.Comment: 58 pages, LaTeX, no figures, Minor error corrected, references added,
The main results of the paper have not change
Asymptotic W-symmetries in three-dimensional higher-spin gauge theories
We discuss how to systematically compute the asymptotic symmetry algebras of
generic three-dimensional bosonic higher-spin gauge theories in backgrounds
that are asymptotically AdS. We apply these techniques to a one-parameter
family of higher-spin gauge theories that can be considered as large N limits
of SL(N) x SL(N) Chern-Simons theories, and we provide a closed formula for the
structure constants of the resulting infinite-dimensional non-linear
W-algebras. Along the way we provide a closed formula for the structure
constants of all classical W_N algebras. In both examples the higher-spin
generators of the W-algebras are Virasoro primaries. We eventually discuss how
to relate our basis to a non-primary quadratic basis that was previously
discussed in literature.Comment: 61 page
A Genome-Wide Analysis of Promoter-Mediated Phenotypic Noise in Escherichia coli
Gene expression is subject to random perturbations that lead to fluctuations in the rate of protein production. As a consequence, for any given protein, genetically identical organisms living in a constant environment will contain different amounts of that particular protein, resulting in different phenotypes. This phenomenon is known as “phenotypic noise.” In bacterial systems, previous studies have shown that, for specific genes, both transcriptional and translational processes affect phenotypic noise. Here, we focus on how the promoter regions of genes affect noise and ask whether levels of promoter-mediated noise are correlated with genes' functional attributes, using data for over 60% of all promoters in Escherichia coli. We find that essential genes and genes with a high degree of evolutionary conservation have promoters that confer low levels of noise. We also find that the level of noise cannot be attributed to the evolutionary time that different genes have spent in the genome of E. coli. In contrast to previous results in eukaryotes, we find no association between promoter-mediated noise and gene expression plasticity. These results are consistent with the hypothesis that, in bacteria, natural selection can act to reduce gene expression noise and that some of this noise is controlled through the sequence of the promoter region alon
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