‘Like, I’m playing, but with this’. Materialization and affect in early childhood literacy

The more-than-human turn in early childhood education has highlighted the relevance of children’s intra-actions with their environment, as well as the multiple ways in which worlds and literacies emerge in them. The rejection of representationalism as the single source of knowledge leads to the consideration of affect, embodiment, memories, sound and movement as ways of knowing. The ways in which they manifest in a school context deserve close attention to the tiny details of literacy events. Our research presents a diffractive reading of an event in a school classroom, aiming to understand human and more-than-human intra-actions in this context, the re-configurations of time, space and matter, and the ways in which children articulate entanglements with texts and bodies. We focus on the intra-actions of a seven-year old child with a photo of his favourite videogame and the ways in which affect and memory emerge. The child’s sounds and movements, the researcher, the photo and the space become entangled to re-configure time, space and matter. Our analysis provides an insight into an event often occurring in schools. We offer some clues to understand it as part of the language and literacy practices of children, and pose the necessity of reconsidering the usual concept of literacy in school.

Smooth 1-Dimensional Algebraic Quantum Field Theories

This paper proposes a refinement of the usual concept of algebraic quantum field theories (AQFTs) to theories that are smooth in the sense that they assign to every smooth family of spacetimes a smooth family of observable algebras. Using stacks of categories, this proposal is realized concretely for the simplest case of 1-dimensional spacetimes, leading to a stack of smooth 1-dimensional AQFTs. Concrete examples of smooth AQFTs, of smooth families of smooth AQFTs and of equivariant smooth AQFTs are constructed. The main open problems that arise in upgrading this approach to higher dimensions and gauge theories are identified and discussed.

Cosmological Milestones and Gravastars - Topics in General Relativity

<p>In this thesis, we consider two different problems relevant to general relativity. Overthe last few years, opinions on physically relevant singularities occurring in FRWcosmologies have considerably changed. We present an extensive catalogue of suchcosmological milestones using generalized power series both at the kinematical anddynamical level. We define the notion of “scale factor singularity” and explore its relationto polynomial and differential curvature singularities. We also extract dynamicalinformation using the Friedmann equations and derive necessary and sufficient conditionsfor the existence of cosmological milestones such as big bangs, big crunches, bigrips, sudden singularities and extremality events. Specifically, we provide a completecharacterization of cosmological milestones for which the dominant energy conditionis satisfied. The second problem looks at one of the very small number of seriousalternatives to the usual concept of an astrophysical black hole, that is, the gravastarmodel developed by Mazur and Mottola. By considering a generalized class of similarmodels with continuous pressure (no infinitesimally thin shells) and negative centralpressure, we demonstrate that gravastars cannot be perfect fluid spheres: anisotropcpressures are unavoidable. We provide bounds on the necessary anisotropic pressureand show that these transverse stresses that support a gravastar permit a higher compactnessthan is given by the Buchdahl–Bondi bound for perfect fluid stars. We alsocomment on the qualitative features of the equation of state that such gravastar-likeobjects without any horizon must have.</p>

Cosmological Milestones and Gravastars - Topics in General Relativity

<p>In this thesis, we consider two different problems relevant to general relativity. Overthe last few years, opinions on physically relevant singularities occurring in FRWcosmologies have considerably changed. We present an extensive catalogue of suchcosmological milestones using generalized power series both at the kinematical anddynamical level. We define the notion of “scale factor singularity” and explore its relationto polynomial and differential curvature singularities. We also extract dynamicalinformation using the Friedmann equations and derive necessary and sufficient conditionsfor the existence of cosmological milestones such as big bangs, big crunches, bigrips, sudden singularities and extremality events. Specifically, we provide a completecharacterization of cosmological milestones for which the dominant energy conditionis satisfied. The second problem looks at one of the very small number of seriousalternatives to the usual concept of an astrophysical black hole, that is, the gravastarmodel developed by Mazur and Mottola. By considering a generalized class of similarmodels with continuous pressure (no infinitesimally thin shells) and negative centralpressure, we demonstrate that gravastars cannot be perfect fluid spheres: anisotropcpressures are unavoidable. We provide bounds on the necessary anisotropic pressureand show that these transverse stresses that support a gravastar permit a higher compactnessthan is given by the Buchdahl–Bondi bound for perfect fluid stars. We alsocomment on the qualitative features of the equation of state that such gravastar-likeobjects without any horizon must have.</p>

Crossover from two-frequency pulse compounds to escaping solitons

The nonlinear interaction of copropagating optical solitons enables a large variety of intriguing bound-states of light. We here investigate the interaction dynamics of two initially superimposed fundamental solitons at distinctly different frequencies. Both pulses are located in distinct domains of anomalous dispersion, separated by an interjacent domain of normal dispersion, so that group velocity matching can be achieved despite a vast frequency gap. We demonstrate the existence of two regions with different dynamical behavior. For small velocity mismatch we observe a domain in which a single heteronuclear pulse compound is formed, which is distinct from the usual concept of soliton molecules. The binding mechanism is realized by the mutual cross phase modulation of the interacting pulses. For large velocity mismatch both pulses escape their mutual binding and move away from each other. The crossover phase between these two cases exhibits two localized states with different velocity, consisting of a strong trapping pulse and weak trapped pulse. We detail a simplified theoretical approach which accurately estimates the parameter range in which compound states are formed. This trapping-to-escape transition allows to study the limits of pulse-bonding as a fundamental phenomenon in nonlinear optics, opening up new perspectives for the all-optical manipulation of light by light.

Path-dependent martingale problems and additive functionals

The paper introduces and investigates the natural extension to the path-dependent setup of the usual concept of canonical Markov class introduced by Dynkin and which is at the basis of the theory of Markov processes. That extension, indexed by starting paths rather than starting points, will be called path-dependent canonical class. Associated with this is the generalization of the notions of semi-group and of additive functionals to the path-dependent framework. A typical example of such family is constituted by the laws [Formula: see text], where for fixed time [Formula: see text] and fixed path [Formula: see text] defined on [Formula: see text], [Formula: see text] is the (unique) solution of a path-dependent martingale problem or more specifically the weak solution of a path-dependent SDE with jumps, with initial path [Formula: see text]. In a companion paper we apply those results to study path-dependent analysis problems associated with BSDEs.

Morte, linguagem e xamanismo em "Passagem das horas" de Álvaro de Campos

O presente trabalho tem como objetivo realizar uma análise da estrutura do poema “Passagem das horas” de Álvaro de Campos. Ao considerar o próprio desenvolvimento dos versos, a manifestação da morte na linguagem poética tal como aqui aparece, intenciona-se pensar de que forma a variação linguística no estilo de Álvaro de Campos é uma forma de morte e uma ruptura com relação à usual concepção de morte, a realização de um êxtase, que em termos semióticos, considera-se xamânico. A esse propósito, investigar-se-ão as particularidades de cada uma das três seções do poema. Primeiro, o eu lírico reconta as lembranças várias de sua própria vida, a partir da qual constitui-se um sensacionismo nostálgico. Segundo, o eu lírico angustia-se diante da morte, em termos de uma linguagem antitética e anafórica. Terceiro, o eu lírico realiza uma aclamação à morte ou um transe xamânico, pois ao personificar a morte em dama da noite, ama-a fervorosamente, demonstra o estatuto criativo e curativo da linguagem considerada delirante e, evidentemente, a indiscernibilidade entre criação, morte e delírio. *** Death, language and shamanism in "Passage of the hours" by Álvaro de Campos ***The present work aims to analyze the structure of the poem "Passage of the Hours" by Álvaro de Campos. In considering the development of the verses themselves, the manifestation of death in poetic language as it appears here, one intends to think of how linguistic variation in the style of Alvaro de Campos is a form of death and a rupture with respect to the usual concept of death, the constitution of an ecstasy, which in semiotic terms, is considered shamanic. In this regard, the particularities of each of the three sections of the poem will be investigated. First, the lyrical self retells the various memories of its own life, from which nostalgic sensation is created. Second, the lyrical self anguishes before death, in terms of an antithetic and anaphoric language. Third, the lyrical self performs an acclamation to death or a shamanic trance; by embodying death as a lady of the night, he loves her intensely, demonstrating the creative and curative status of language considered delirious, and evidently the indiscernibility between creation, death, and delirium.Keywords: Death; Language; Shamanism; Stylistics; Álvaro de Campos.

On the Parisian ruin of the dual Lévy risk model

In this paper we investigate the Parisian ruin problem of the general dual Lévy risk model. Unlike the usual concept of ultimate ruin, allowing the surplus level to be negative within a prespecified period indicates that the deficit at Parisian ruin is not necessarily equal to zero. Hence, we consider a Gerber–Shiu type expected discounted penalty function at the Parisian ruin and obtain an explicit expression for this function under the dual Lévy risk model. As particular cases, we calculate the Parisian ruin probability and the expected discountedkth moments of the deficit at the Parisian ruin for the compound Poisson dual risk model and a drift-diffusion model. Numerical examples are given to illustrate the behavior of Parisian ruin and the expected discounted deficit at Parisian ruin.

Diffraction and Polarization Effects in Radiation Heat Transfer: A Case Study

The Monte-Carlo ray-trace (MCRT) method is particularly well suited to the optical design of instrumentation in which very small radiant signals must be separated from a strong background. The present contribution explores an important application lying at the intersection of physical optics and radiation heat transfer. Specifically, we consider instruments intended to monitor the planetary energy budget from low earth orbit. To accommodate the increasingly exigent accuracy requirements imposed by the Earth science community, it has become necessary to include effects such as diffraction and polarization that are normally omitted in traditional radiation heat transfer modeling. This requires that the usual concept of a “ray” be extended to include wavelength, a phase angle, and polarization. A realistic instrument concept is considered that fully exercises the ability of such an approach to capture optical effects that are either ignored or assessed “offline” in traditional modeling efforts. Investigated is the range of variation of detector illumination when the effects of the source spectral content, diffraction, and polarization are included.

Subspace confinement for switched linear systems

In this note, we introduce the asymptotic subspace confinement problem, generalizing the usual concept of convergence in discrete-time linear systems. Instead of precise convergence, subspace confinement only requires the convergence of states to a certain subspace of the state space, offering useful flexibility and applicability. We establish a criterion for deciding the asymptotic subspace confinement, drawing upon a general finiteness result for the infinite product of matrices. Our results indicate that the asymptotic subspace confinement problem is algorithmically decidable when an invariant subspace for the set of matrices and some polytope norms are given.