Charged AdS Black Holes and Catastrophic Holography

We compute the properties of a class of charged black holes in anti-de Sitter space-time, in diverse dimensions. These black holes are solutions of consistent Einstein-Maxwell truncations of gauged supergravities, which are shown to arise from the inclusion of rotation in the transverse space. We uncover rich thermodynamic phase structures for these systems, which display classic critical phenomena, including structures isomorphic to the van der Waals-Maxwell liquid-gas system. In that case, the phases are controlled by the universal `cusp' and `swallowtail' shapes familiar from catastrophe theory. All of the thermodynamics is consistent with field theory interpretations via holography, where the dual field theories can sometimes be found on the world volumes of coincident rotating branes.Comment: 19 pages, revtex, psfig, 6 multicomponent figures, typos, references and a few remarks have been repaired, and adde

Method to compute the stress-energy tensor for the massless spin 1/2 field in a general static spherically symmetric spacetime

A method for computing the stress-energy tensor for the quantized, massless, spin 1/2 field in a general static spherically symmetric spacetime is presented. The field can be in a zero temperature state or a non-zero temperature thermal state. An expression for the full renormalized stress-energy tensor is derived. It consists of a sum of two tensors both of which are conserved. One tensor is written in terms of the modes of the quantized field and has zero trace. In most cases it must be computed numerically. The other tensor does not explicitly depend on the modes and has a trace equal to the trace anomaly. It can be used as an analytic approximation for the stress-energy tensor and is equivalent to other approximations that have been made for the stress-energy tensor of the massless spin 1/2 field in static spherically symmetric spacetimes.Comment: 34 pages, no figure

Unimodular bimode gravity and the coherent scalar-graviton field as galaxy dark matter

The explicit violation of the general gauge invariance/relativity is adopted as the origin of dark matter and dark energy of the gravitational nature. The violation of the local scale invariance alone, with the residual unimodular one, is considered. Besides the four-volume preserving deformation mode -- the transverse-tensor graviton -- the metric comprises a compression mode -- the scalar graviton, or the systolon. A unimodular invariant and general covariant metric theory of the bimode/scalar-tensor gravity is consistently worked out. To reduce the primordial ambiguity of the theory a dynamical global symmetry is imposed, with its subsequent spontaneous breaking revealed. The static spherically symmetric case in the empty, but possibly for the origin, space is studied. A three-parameter solution describing a new static space structure -- the dark lacuna -- is constructed. It enjoys the property of gravitational confinement, with the logarithmic potential of gravitational attraction at the periphery, and results in the asymptotically flat rotation curves. Comprising a super-massive dark fracture (a scalar-modified black hole) at the origin surrounded by a cored dark halo, the dark lacunas are proposed as a prototype model of galaxies, implying an ultimate account for the distributed non-gravitational matter and a putative asphericity or rotation.Comment: 38 pages, 10 figures; exposition improved, remarks added, accepted for publicatio

Unruh--DeWitt detectors in spherically symmetric dynamical space-times

In the present paper, Unruh--DeWitt detectors are used in order to investigate the issue of temperature associated with a spherically symmetric dynamical space-times. Firstly, we review the semi-classical tunneling method, then we introduce the Unruh--DeWitt detector approach. We show that for the generic static black hole case and the FRW de Sitter case, making use of peculiar Kodama trajectories, semiclassical and quantum field theoretic techniques give the same standard and well known thermal interpretation, with an associated temperature, corrected by appropriate Tolman factors. For a FRW space-time interpolating de Sitter space with the Einstein--de Sitter universe (that is a more realistic situation in the frame of $\Lambda$CDM cosmologies), we show that the detector response splits into a de Sitter contribution plus a fluctuating term containing no trace of Boltzmann-like factors, but rather describing the way thermal equilibrium is reached in the late time limit. As a consequence, and unlike the case of black holes, the identification of the dynamical surface gravity of a cosmological trapping horizon as an effective temperature parameter seems lost, at least for our co-moving simplified detectors. The possibility remains that a detector performing a proper motion along a Kodama trajectory may register something more, in which case the horizon surface gravity would be associated more likely to vacuum correlations than to particle creation.Comment: 19 pages, to appear on IJTP. arXiv admin note: substantial text overlap with arXiv:1101.525

Oviposição do curuquerê e alimentação de suas lagartas neonatas em algodoeiros tratados com caulim

Resumo: O objetivo deste trabalho foi avaliar a capacidade do caulim de afetar a oviposição e a alimentação de Alabama argillacea (Lepidoptera: Noctuidae) em algodoeiro. Determinou-se a preferência de oviposição, a viabilidade de ovos e o consumo das lagartas de primeiro instar de A. argillacea, em folhas de algodão tratadas ou não com caulim. A preferência de oviposição foi determinada por teste de escolha e confinamento, em delineamento experimental de blocos ao acaso, em arranjo fatorial 2x7, representado pelos tratamentos com caulim em água destilada (60 g L-1) ou somente água destilada (testemunha), e pela avaliação de sete estruturas vegetais da planta. O consumo pelas lagartas de primeiro instar foi determinado em delineamento experimental inteiramente casualizado, em arranjo fatorial 2x4, representado pelo tratamento com caulim em água destilada, pela testemunha e pelos quatro períodos de observação (6, 12, 24 e 48 horas). A oviposição das mariposas do curuquerê-do-algodoeiro foi reduzida nas plantas de algodão tratadas com caulim; no entanto, a viabilidade dos ovos não foi afetada. A folha da haste foi a estrutura preferida para oviposição. A sobrevivência e o consumo de lagartas de primeiro instar do curuquerê são menores nas plantas de algodão tratadas com caulim

Alternatively spliced tissue factor contributes to tumor spread and activation of coagulation in pancreatic ductal adenocarcinoma

Thrombosis and Hemostasi