From Little Words, Big Words Grow: Annotations on the Yo, Sí Puedo Experience in Brewarrina, Australia

This article is a reflection on the application of the Cuban literacy methodology Yo, Sí Puedo to the Australian setting. The Yo, Sí Puedo / Yes, I Can! model developed in Cuba by the Instituto Pedagógico Latinoamericano y Caribeño, IPLAC (Institute of Pedagogy for Latin America and the Caribbean) has been successfully implemented across the Global South as a strategy of adult literacy. It is a legacy of our Latin American revolutionary roots, with its origin in the Freirean pedagogy of the oppressed. Expanding across continents this model continues to teach reading and writing to disenfranchised adults in marginal and Indigenous communities, from the Argentinean Chaco to Brewarrina in northern NSW, Australia. Its aim is to contribute to the hope of improving the health and educational outcomes of the country’s First Peoples. This article is indebted to conversations with the Cuban advisor of Yes, I Can!, José Manuel Chala Leblanch. Observing him working in the classroom setting of Brewarrina touched me at different levels: personally because it reminded me of my own family experiences with the education system in my country, Argentina; and professionally as an educator negotiating different languages and cultures. It also reinforced my belief in the importance of incorporating Indigenous ways of learning and teaching to Western styles of teaching and learning. I built this reflection moving from personal and poetic—visual and textual—narratives and observations to academic interventions informed by researched literature on adult and Indigenous education

Multi-stage quantum absorption heat pumps

It is well known that heat pumps, while being all limited by the same basic thermodynamic laws, may find realization on systems as "small" and "quantum" as a three-level maser. In order to quantitatively assess how the performance of these devices scales with their size, we design generalized $N$-dimensional ideal heat pumps by merging $N-2$ elementary three-level stages. We set them to operate in the absorption chiller mode between given hot and cold baths, and study their maximum achievable cooling power and the corresponding efficiency as a function of $N$. While the efficiency at maximum power is roughly size-independent, the power itself slightly increases with the dimension, quickly saturating to a constant. Thus, interestingly, scaling up autonomous quantum heat pumps does not render a significant enhancement beyond the optimal double-stage configuration.Comment: 7 pages, 3 figure

The tetrahexahedric angular Calogero model

The spherical reduction of the rational Calogero model (of type $A_{n-1}$ and after removing the center of mass) is considered as a maximally superintegrable quantum system, which describes a particle on the $(n{-}2)$-sphere subject to a very particular potential. We present a detailed analysis of the simplest non-separable case, $n{=}4$, whose potential is singular at the edges of a spherical tetrahexahedron. A complete set of independent conserved charges and of Hamiltonian intertwiners is constructed, and their algebra is elucidated. They arise from the ring of polynomials in Dunkl-deformed angular momenta, by classifying the subspaces invariant and antiinvariant under all Weyl reflections, respectively.Comment: 1+29 pages, 4 figures; v2: Introduction extended, eq.(5.16) and one ref. added, published versio

Thermodynamics of Lovelock black holes with a nonminimal scalar field

We source the Lovelock gravity theories indexed by an integer k and fixed by requiring a unique anti-de Sitter vacuum with a self-interacting nonminimal scalar field in arbitrary dimension d. For each inequivalent Lovelock gravity theory indexed by the integer k, we establish the existence of a two-parametric self-interacting potential that permits to derive a class of black hole solutions with planar horizon for any arbitrary value of the nonminimal coupling parameter. In the thermodynamical analysis of the solution, we show that, once regularized the Euclidean action, the mass contribution coming form the gravity side exactly cancels, order by order, the one arising from the matter part yielding to a vanishing mass. This result is in accordance with the fact that the entropy of the solution, being proportional to the lapse function evaluated at the horizon, also vanishes. Consequently, the integration constant appearing in the solution is interpreted as a sort of hair which turns out to vanish at high temperature.Comment: 11 page

PT{\cal PT} deformation of angular Calogero models

The rational Calogero model based on an arbitrary rank-$n$ Coxeter root system is spherically reduced to a superintegrable angular model of a particle moving on $S^{n-1}$ subject to a very particular potential singular at the reflection hyperplanes. It is outlined how to find conserved charges and to construct intertwining operators. We deform these models in a ${\cal PT}$-symmetric manner by judicious complex coordinate transformations, which render the potential less singular. The ${\cal PT}$ deformation does not change the energy eigenvalues but in some cases adds a previously unphysical tower of states. For integral couplings the new and old energy levels coincide, which roughly doubles the previous degeneracy and allows for a conserved nonlinear supersymmetry charge. We present the details for the generic rank-two ($A_2$, $G_2$) and all rank-three Coxeter systems ($AD_3$, $BC_3$ and $H_3$), including a reducible case ($A_1^{\otimes 3}$).Comment: 1+41 pages, 12 figure

The Economic Impact of Telecommunications Diffusion on UK Productivity Growth

This paper investigates the relationship between telecommunications infrastructure competition, investment and productivity. Using econometric modelling and input-output economics, the analysis examines and measures the extent to which telecommunications has contributed to national and sectoral productivity performance. The main findings from this paper suggests that most industries have benefited from the incorporation of advances of telecommunications technology, which might have, amongst other things, emanated from encouraging infrastructure investment, in their production processes. Thus the analysis demonstrates that U.K. government policies on telecommunications and its investment incentives may have wide-reaching consequences for not only the telecommunications industry but also the economy as a whole.Productivity, Input-output analysis, Technical change, Telecommunications