Constraining ultra large-scale cosmology with multiple tracers in optical and radio surveys

Multiple tracers of the cosmic density field, with different bias, number and luminosity evolution, can be used to measure the large-scale properties of the Universe. We show how an optimal combination of tracers can be used to detect general-relativistic effects in the observed density of sources. We forecast for the detectability of these effects, as well as measurements of primordial non-Gaussianity and large-scale lensing magnification with current and upcoming large-scale structure experiments. In particular we quantify the significance of these detections in the short term with experiments such as the Dark Energy Survey (DES), and in the long term with the Large Synoptic Survey Telescope (LSST) and the Square Kilometre Array (SKA). We review the main observational challenges that must be overcome to carry out these measurements.Comment: 19 pages, 10 figure

Reconstructing cosmic growth with kSZ observations in the era of Stage IV experiments

Future ground-based CMB experiments will generate competitive large-scale structure datasets by precisely characterizing CMB secondary anisotropies over a large fraction of the sky. We describe a method for constraining the growth rate of structure to sub-1% precision out to $z\approx 1$, using a combination of galaxy cluster peculiar velocities measured using the kinetic Sunyaev-Zel'dovich (kSZ) effect, and the velocity field reconstructed from galaxy redshift surveys. We consider only thermal SZ-selected cluster samples, which will consist of $\mathcal{O}(10^4-10^5)$ sources for Stage 3 and 4 CMB experiments respectively. Three different methods for separating the kSZ effect from the primary CMB are compared, including a novel blind "constrained realization" method that improves signal-to-noise by a factor of $\sim 2$ over a commonly-used aperture photometry technique. Measurements of the integrated tSZ $y$-parameter are used to break the kSZ velocity-optical depth degeneracy, and the effects of including CMB polarization and SZ profile uncertainties are also considered. A combination of future Stage 4 experiments should be able to measure the product of the growth and expansion rates, $\alpha\equiv f H$, to better than 1% in bins of $\Delta z = 0.1$ out to $z \approx 1$ -- competitive with contemporary redshift-space distortion constraints from galaxy surveys.Comment: 16 pages, 8 figure

Private body of culture: simbolic industry, freedom and commons.

De la cultura, campo de individuación psíquica y colectiva, depende el diseño de la memoria y el olvido de las comunidades. Ella marca la experiencia simbólica de la vida cotidiana, las relaciones sociales y las instituciones situadas entre el empoderamiento individual y los movimientos de masas. Si es diseñada desde las corporaciones o dominada por abstracciones hegemónicas de sociabilidad como es el mercado, o sometida a las dudas entre los modelos privados o estatales, se escapa un campo a veces tan invisible como urgente: el procomún. En este contexto global tecnoeconómico, donde el conocimiento científico, la información y el entretenimiento son las mercancías elementales del diseño post-industrial, la protección de antiguos y nuevos bienescomunes exige una demanda teórica y creación práctica de otros paradigmas políticos basados en los valores de la libertad, del acceso abierto y de la compartición social de las facultades creativas. El sistema capitalista ya no ofrece soluciones válidas para una gran parte de la humanidad. La ciudad postindustrial del siglo XXI constituye simultáneamente un depósito de gente desempleada y la promesa de otras economías morales posibles. Esta ilusión potencial exige otra representación de la tecnología que integre la posibilidad de expresiones culturales autónomas, condiciones de la variabilidad y de la democratización simbólica.Communities rely on culture to design memories and forgetfulness because culture is the field for collective and individual identity. Culture imprints the symbolic experience of everyday life; also shapes relationships among social institutions, masses and individual empowerment. If corporations, the privates or the State, in a hesitant attitude caused by social abstractions, shape culture, there is a tertium quid sometimes invisible such as the commons. In a context where global economy and technology transform scientific knowledge, information, and entertainment into postindustrial commodities, defending the new commons implies the search for a care and, at the same time, the creation of new political paradigms based on freedom, free access and openness. Capitalism does not offer valid alternatives for a big deal of humanity. The 21st post-industrial city becomes a depot for unemployed people reflecting another possible moral economies. In that reflection there should be another perception of technology together with a cultural homegrown and autonomous expression as required for variability and symbolic democratization

Middle class evolving to precariat: labour conditions for the 21st Century

Depto. de Trabajo Social y Servicios SocialesFac. de Trabajo SocialTRUEpu

Lorentz-violating effects on topological defects generated by two real scalar fields

The influence of a Lorentz-violation on soliton solutions generated by a system of two coupled scalar fields is investigated. Lorentz violation is induced by a fixed tensor coefficient that couples the two fields. The Bogomol'nyi method is applied and first-order differential equations are obtained whose solutions minimize energy and are also solutions of the equations of motion. The analysis of the solutions in phase space shows how the stability is modified with the Lorentz violation. It is shown explicitly that the solutions preserve linear stability despite the presence of Lorentz violation. Considering Lorentz violation as a small perturbation, an analytical method is employed to yield analytical solutions.Comment: (9 pages, 11 figures

Interaction between renewable energy consumption and dematerialization: insights based on the material footprint and the Environmental Kuznets Curve

This paper investigates the effect of renewable energy consumption on material consumption, considering the relationship between Material Footrprint and Gross Domestic Product (GDP), and testing the assumptions of the Environmental Kuznets Curve. A STIRPAT variation is used to specify a model relating the Material Footprint to renewable energy consumption and GDP. The effect is tested for the Material Footprint of fossil fuels and for the Material Footprint of the other categories. The analysis is applied to the seven European countries with the highest proportion of renewable energy consumption. The model estimation shows that the relationship between GDP and Material Footprint follows an inverted N-shaped form, and that the renewable energy favours the reduction of the material consumption of fossil fuels. However, there is a positive effect between the renewable energy consumption and the Material Footprint of the other categories beyond fossil fuels. These results must be interpreted considering the context, as the development of renewable energy coincides with the effects of the 2008 crisis, which may distort the relation between the variables. To pose dematerialization scenarios, it seems necessary to consider reducing energy consumption even if it comes from renewable sourcesS

Extractivism, ecologically unequal exchange and environmental impact in South America: a study using Material Flow Analysis (1990–2017)

With the economic and trade liberalisation policies of the late 20th century, the extraction of natural resources for export, known as extractivism, became the central axis of South American economies. This development model has a significant environmental impact and has generated imbalances in the South American productive structure that lead to chronically unfavourable terms of trade for the region. The different price dynamics of exports and imports trap South America in a vicious circle that leads to a progressive need to increase the volume of resources it extracts. Consequently, South America maintains a situation of ecologically unequal exchange that implies the absorption of an ever-increasing environmental impact from the rest of the world. All this calls into question the benefits of free trade, especially in ecological terms, as well as the compatibility between economic growth and the reduction of environmental impacS

An Approximation to the Environmental Impact of Economic Growth Using the Material Flow Analysis: Differences between Production and Consumption Methods, Applied to China, United Kingdom and USA (1990–2017)

The relationship between economic growth and environmental impact has become a recurrent subject of research in recent years. Currently, results that indicate that the accumulation of economic growth leads to a reduction in environmental impact coexist with others that do not show any evidence in this respect. This paper aims to analyse this relationship using Material Flow Analysis through the two most frequent methods: territorial or production and consumption. For this purpose, data from China, the United Kingdom and the USA from 1990–2017 are used. The results show that the method used influences the conclusions, mainly due to differences in the accounting of physical trade flows. The production method, in which physical trade flows coincide with monetary trade flows, tends to underestimate the material consumption of rich, importing countries, while overestimating that of exporting countries. Policies based on this method have limited capacity to reduce global environmental impacts. The consumption method allows the environmental impact to be allocated to each country in a way that is more in line with its true material requirementsS

Influence of the matrix and polymerization methods on the synthesis of BC/PANi nanocomposites: an IGC study

Inverse gas chromatography (IGC) is a technique for evaluating surface properties. The current work emphasizes the use of IGC to evaluate the surface physicochemical changes during different bacterial cellulose (BC) processing methods as well as upon polyaniline (PANi) incorporation. The processing methods (oven-drying, freeze-drying, and regeneration) caused changes in the BC surface group distribution, where upon freeze-drying and regeneration, a more acidic behavior is obtained, compared to oven-drying (Kb/Ka decreased up to 24%). Through freeze-drying, the structural pore preservation increases (54%) the BC porosity, whereas through regeneration, the porosity decreases (23%), compared to BC oven-drying. Regarding the nanocomposites, with PANi incorporation, the overall properties evaluated by IGC were significantly changed. The γtotals increases up to 150%, indicating a more reactive surface in the nanocomposites. Also, is observed a sevenfold increase in the Kb/Ka and a less porous surface (up to 85%). Hence, the current work highlights the use of IGC as a viable technique to evaluate the physicochemical changes upon different BC modifications.info:eu-repo/semantics/publishedVersio

Surface modification of banana fibers using organosilanes: an IGC insight

Banana fibers are an agricultural waste material with a great exploitation potential due to their cellulose-rich content. Raw banana fibers (RBF) were treated with 3-aminopropyltriethoxy silane and glycidoxypropyltrimethoxy silane to improve the inherent limitations of banana fibers, namely its poor cell adhesion. The fibers’ modification was evaluated by inverse gas chromatography (IGC). Similar cs d values were observed between the RBF and silane-treated fibers (39–41 mJ/m2 ), which indicates similar reactivity towards apolar probes. However, the decrease in the entropic parameter indicates the silane covalent bonding with the cellulose chains making a stiffer structure. Organosilane grafting was confirmed by an increased basic character in the silane-treated fibers (Kb/Ka from 1.03 to 2.81). The surface morphology also changed towards higher contact area (SBET increases 6.7 times) and porosity (Dp increases up to 67%). Both morphological and functional group reactivity changes suggest that the organosilane treatment offers new opportunities for these fibers to be used as adsorbents for proteins as well as to cell adhesion. Therefore, IGC proved a simple and viable technique in the characterization of silane-treated fibers.info:eu-repo/semantics/publishedVersio