FRW and domain walls in higher spin gravity

We present exact solutions to Vasiliev's bosonic higher spin gravity equations in four dimensions with positive and negative cosmological constant that admit an interpretation in terms of domain walls, quasi-instantons and Friedman-Robertson-Walker (FRW) backgrounds. Their isometry algebras are infinite dimensional higher-spin extensions of spacetime isometries generated by six Killing vectors. The solutions presented are obtained by using a method of holomorphic factorization in noncommutative twistor space and gauge functions. In interpreting the solutions in terms of Fronsdal-type fields in spacetime, a field-dependent higher spin transformation is required, which is implemented at leading order. To this order, the scalar field solves Klein-Gordon equation with conformal mass in (anti) de Sitter space. We interpret the FRW solution with de Sitter asymptotics in the context of inflationary cosmology and we expect that the domain wall and FRW solutions are associated with spontaneously broken scaling symmetries in their holographic description. We observe that the factorization method provides a convenient framework for setting up a perturbation theory around the exact solutions, and we propose that the nonlinear completion of particle excitations over FRW and domain wall solutions requires black hole-like states.Comment: 63 page

Non-Gaussianities due to Relativistic Corrections to the Observed Galaxy Bispectrum

High-precision constraints on primordial non-Gaussianity (PNG) will significantly improve our understanding of the physics of the early universe. Among all the subtleties in using large scale structure observables to constrain PNG, accounting for relativistic corrections to the clustering statistics is particularly important for the upcoming galaxy surveys covering progressively larger fraction of the sky. We focus on relativistic projection effects due to the fact that we observe the galaxies through the light that reaches the telescope on perturbed geodesics. These projection effects can give rise to an effective $f_{\rm NL}$ that can be misinterpreted as the primordial non-Gaussianity signal and hence is a systematic to be carefully computed and accounted for in modelling of the bispectrum. We develop the technique to properly account for relativistic effects in terms of purely observable quantities, namely angles and redshifts. We give some examples by applying this approach to a subset of the contributions to the tree-level bispectrum of the observed galaxy number counts calculated within perturbation theory and estimate the corresponding non-Gaussianity parameter, $f_{\rm NL}$, for the local, equilateral and orthogonal shapes. For the local shape, we also compute the local non-Gaussianity resulting from terms obtained using the consistency relation for observed number counts. Our goal here is not to give a precise estimate of $f_{\rm NL}$ for each shape but rather we aim to provide a scheme to compute the non-Gaussian contamination due to relativistic projection effects. For the terms considered in this work, we obtain contamination of $f_{\rm NL}^{\rm loc} \sim {\mathcal O}(1)$.Comment: 31 pages, 6 figures, Typos corrected to match the published version in JCA

Cultivo del brócoli, alternativa de producción hortícola en el oriente antioqueño.

Se refiere al cultivo del brócoli, Brassica oleracea como alternativa de producción para el oriente antioqueño de Colombia, indicando el valor nutritivo de la hortaliza, los requerimientos de clima, suelo y semillas, las distancias de siembra, variedades e híbridos aconsejados y las prácticas de fertilización, desyerba y riego. Se mencionan algunas plagas y enfermedades presentes en la región como Peronospora parasítica, Xanthomonas campestris, Alternaria sp. y la polilla del repollo, Plutella xylostella. Se dan instrucciones sobre cosecha y empaque del producto y su utilizaciónBrócoli-Brassica oleracea var. italic

Producción comercial de hortalizas en el centro de investigación "La Selva": un a estrategia de investigación, validación y transferencia de tecnología

Con este trabajo se busca ofrecer nuevas alternativas a los horticultores, teniendo un permanente contacto con toda la cadena de producción y fue así como se incursionó en nuevos esquemas de transporte, empaque y valor agregado. Se orientaron trabajos de poscosecha que permitieron un mejor aprovechamiento de los productos de segunda

Situación patológica de las hortalizas cultivadas en el oriente antioqueño.

Se indican los principales problemas fitopatológicos de las hortalizas en el Oriente Antioqueño, con énfasis en los cultivos de tomate, zanahoria, repollo, pimentón, remolacha, lechuga, cebolla de rama y coliflor. En relación con el tomate se mencionan los hongos Phytophthora infestans, Phoma andina, Xanthomonas campestris, Pseudomonas solanacearum, Alternaria solani y Botrytis cinerea principalmente. La zanahoria es atacada por los siguientes patógenos: Cercospora carotae, Alternaria dauci, el nematodo Meloidogyne spp. y por los hongos Rosellinia, Sclerotium rolfsii y Pythium. En el repollo se presenta ataque de Xanthomonas campestris, Mycosphaerela brassicola y Alternaria brassicae. En pimentón Alternaria solani, Cercospora capsci y Brotrytis cinerea. En las demás hortalizas prevalecen los hongos Cercospora beticola en remolacha, Sclerotinia sclerotiorum en lechuga y Alternaria porri y Peronospara destructor en ceboll

Khronon inflation

We study the possibility that the approximate time shift symmetry during inflation is promoted to the full invariance under time reparametrization t \to \tilde t(t), or equivalently under field redefinition of the inflaton \phi \to \tilde\phi(\phi). The symmetry allows only two operators at leading order in derivatives, so that all n-point functions of scalar perturbations are fixed in terms of the power spectrum normalization and the speed of sound. During inflation the decaying mode only decays as 1/a and this opens up the possibility to violate some of the consistency relations in the squeezed limit, although this violation is suppressed by the (small) breaking of the field reparametrization symmetry. In particular one can get terms in the 3-point function that are only suppressed by 1/k_L in the squeezed limit k_L \to 0 compared to the local shape.Comment: 15 pages, 1 figure, v2. changes regarding the violation of the consistency relation. JCAP published versio

Conformal consistency relations for single-field inflation

We generalize the single-field consistency relations to capture not only the leading term in the squeezed limit---going as 1/q^3, where q is the small wavevector---but also the subleading one, going as 1/q^2. This term, for an (n+1)-point function, is fixed in terms of the variation of the n-point function under a special conformal transformation; this parallels the fact that the 1/q^3 term is related with the scale dependence of the n-point function. For the squeezed limit of the 3-point function, this conformal consistency relation implies that there are no terms going as 1/q^2. We verify that the squeezed limit of the 4-point function is related to the conformal variation of the 3-point function both in the case of canonical slow-roll inflation and in models with reduced speed of sound. In the second case the conformal consistency conditions capture, at the level of observables, the relation among operators induced by the non-linear realization of Lorentz invariance in the Lagrangian. These results mean that, in any single-field model, primordial correlation functions of \zeta are endowed with an SO(4,1) symmetry, with dilations and special conformal transformations non-linearly realized by \zeta. We also verify the conformal consistency relations for any n-point function in models with a modulation of the inflaton potential, where the scale dependence is not negligible. Finally, we generalize (some of) the consistency relations involving tensors and soft internal momenta.Comment: 26 pages, 1 figure. v2. Corrected typos, notably a sign error in eq. (54). Matches JCAP published versio

The Efficacy of Auditory Perceptual Training for Tinnitus: A Systematic Review

Auditory perceptual training affects neural plasticity and so represents a potential strategy for tinnitus management. We assessed the effects of auditory perceptual training on tinnitus perception and/or its intrusiveness via a systematic review of published literature. An electronic database search using the keywords ‘tinnitus and learning’ or ‘tinnitus and training’ was conducted, updated by a hand search. The ten studies identified were reviewed independently by two reviewers, data were extracted, study quality was assessed according to a number of specific criteria and the information was synthesised using a narrative approach. Nine out of the ten studies reported some significant change in either self-reported or psychoacoustic outcome measures after auditory training. However, all studies were quality rated as providing low or moderate levels of evidence for an effect. We identify a need for appropriately randomised and controlled studies that will generate high-quality unbiased and generalisable evidence to ascertain whether or not auditory perceptual training has a clinically relevant effect on tinnitus

The Effective Theory of Quintessence: the w<-1 Side Unveiled

We study generic single-field dark energy models, by a parametrization of the most general theory of their perturbations around a given background, including higher derivative terms. In appropriate limits this approach reproduces standard quintessence, k-essence and ghost condensation. We find no general pathology associated to an equation of state w_Q < -1 or in crossing the phantom divide w_Q = -1. Stability requires that the w_Q < -1 side of dark energy behaves, on cosmological scales, as a k-essence fluid with a virtually zero speed of sound. This implies that one should set the speed of sound to zero when comparing with data models with w_Q < -1 or crossing the phantom divide. We summarize the theoretical and stability constraints on the quintessential plane (1+w_Q) vs. speed of sound squared.Comment: 35 pages, 5 figures, v3: minor modifications, JCAP published versio

Air monitoring for illegal drugs including new psychoactive substances: A review of trends, techniques and thermal degradation products

The detection of illicit psychotropic substances in both indoor and outdoor air is a challenging analytical discipline and the data from such investigation may provide intelligence in a variety of fields. Applications of drug monitoring in air include providing data on national and international drug consumption trends, as monitored by organisations such as the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) and the United Nations Office on Drugs and Crime (UNODC). Air monitoring enables mapping of illicit drug manufacturing, dealing or consumption in cities and the identification of emergent compounds including the recent proliferation of new psychoactive substances (NPS). The rapid spread of NPS has changed the global drug market with greater diversity and dynamic spread of such compounds over several nations. This review provides an up to date analysis of key thematic areas within this analytical discipline. The process of how illicit psychotropic substances spread from emission sources to the atmosphere is considered alongside the sampling and analytical procedures involved. Applications of the technique applied globally are reviewed with studies ranging from the analysis of individual dwellings through to major international air monitoring campaigns providing evidence on global drug trends. Finally, we consider thermal breakdown products of illicit psychotropic substances including NPS that are released upon heating, combustion or vaping and related potential for exposure to these compounds in the air