Hawking Radiation for Non-minimally Coupled Matter from Generalized 2D Black Hole Models

It is well known that spherically symmetric reduction of General Relativity (SSG) leads to non-minimally coupled scalar matter. We generalize (and correct) recent results to Hawking radiation for a class of dilaton models which share with the Schwarzschild black hole non-minimal coupling of scalar fields and the basic global structure. An inherent ambiguity of such models (if they differ from SSG) is discussed. However, for SSG we obtain the rather disquieting result of a negative Hawking flux at infinity, if the usual recipe for such calculations is applied.Comment: 8 page

Comment on: ``Trace anomaly of dilaton coupled scalars in two dimensions''

The trace anomaly for nonminimally coupled scalars in spherically reduced gravity obtained by Bousso and Hawking (hep-th/9705236) is incorrect. We explain the reasons for the deviations from our correct (published) result which is supported by several other recent papers.Comment: 2 page

On the validity of statistical parametric mapping for nonuniformly and heterogeneously smooth one-dimensional biomechanical data

Nonuniform (non-constant) temporal smoothness can arise in biomechanical processes like impacts, and heterogeneous smoothness (unequal smoothness across observations) can arise in mechanically diverse comparisons such as padded vs. unpadded impacts, where padded dynamics are generally smoother than unpadded dynamics. It has been reported that statistical parametric mapping’s (SPM’s) probability values can be invalid for such cases. The purpose of this paper was to clarify the scope of validity for SPM analysis of nonuniformly and heterogeneously smooth one-dimensional (1D) data. We simulated a variety of nonuniformly and heterogeneously smooth Gaussian 1D data over a range of smoothness values, and computed Type I error rates across 10,000 simulation iterations for each smoothness type. Results showed that, in all cases, SPM accurately controlled error at the prescribed α=0.05. Moreover, the distribution of false positives was uniform across time, implying that all regions are equally likely to produce false positives, irrespective of local roughness. We nevertheless show that cluster-level inferences (i.e., p values specific to local regions of significance) may be over-or-underestimated by approximately 0.01 (for the currently simulated scenarios), but never exceed α by definition. We conclude that SPM’s null hypothesis rejection decisions are valid for both nonuniform and heterogeneous 1D data, but that clusters’ p values may be marginally too small/large in rough/smooth regions, respectively. Since cluster-level p values never exceed α, these p value errors are negligible for hypothesis testing purposes. Nevertheless, inter-cluster p value comparisons should be avoided. Implications for statistical power and general results interpretation are discussed

Diversidade de abelhas (Hymenoptera: Apoidea) em mata de araucária em Santa Catarina

Visando conhecer a apifauna existente em floresta ombrófila mista, realizou-se estudo em duas áreas de mata de araucária em Mafra (SC), de setembro de 2016 a agosto de 2017. Foi amostrado um total de 1.304 indivíduos de 56 táxons, 32 gêneros e cinco subfamílias. Índices de diversidade e equabilidade foram calculados. As plantas visitadas somam 48 espécies de 16 famílias. Asteraceae foi visitada com mais frequência (41,7% dos táxons). Abelhas dos táxons Meliponini, Ceratinini e Halictinae foram prevalentes. A sequência de predominância de subfamílias quanto à diversidade (Apinae seguida de Halictinae) seguiu o padrão transicional entre porções subtropicais e temperadas da região neotropical, com pequeno número de espécies abundantes e alta proporção de singletons, assim como variação sazonal. Apis mellifera correspondeu, em abundância, a 36,34%. A variação dos índices revelou diferença entre as duas áreas em relação à abundância, dominância e riqueza das espécies, evidenciando influência da antropização e sucessão ecológica. A diversidade e a abundância de abelhas estão diminuídas em comparação a estudos anteriores em ambientes próximos ou similares

Non-existence of a dilaton gravity action for the exact string black hole

We prove that no local diffeomorphism invariant two-dimensional theory of the metric and the dilaton without higher derivatives can describe the exact string black hole solution found a decade ago by Dijkgraaf, Verlinde and Verlinde. One of the key points in this proof is the concept of dilaton-shift invariance. We present and solve (classically) all dilaton-shift invariant theories of two-dimensional dilaton gravity. Two such models, resembling the exact string black hole and generalizing the CGHS model, are discussed explicitly.Comment: 24 pages, 3 eps-figures, revised version (more references, clarified some of the discussion