Scattering for nonlinear Schrodinger equation under partial harmonic confinement

We consider the nonlinear Schrodinger equation under a partial quadratic confinement. We show that the global dispersion corresponding to the direction(s) with no potential is enough to prove global in time Strichartz estimates, from which we infer the existence of wave operators thanks to suitable vector-fields. Conversely, given an initial Cauchy datum, the solution is global in time and asymptotically free, provided that confinement affects one spatial direction only. This stems from anisotropic Morawetz estimates, involving a marginal of the position density.Comment: 26 pages. Some typos fixed, especially in Section

The evolution of tropos: Contexts, commitments and adaptivity

Software evolution is the main research focus of the Tropos group at University of Trento (UniTN): how do we build systems that are aware of their requirements, and are able to dynamically reconfigure themselves in response to changes in context (the environment within which they operate) and requirements. The purpose of this report is to offer an overview of ongoing work at UniTN. In particular, the report presents ideas and results of four lines of research: contextual requirements modeling and reasoning, commitments and goal models, developing self-reconfigurable systems, and requirements awareness

Tensor-multi-scalar theories: relativistic stars and 3+1 decomposition

Gravitational theories with multiple scalar fields coupled to the metric and each other --- a natural extension of the well studied single-scalar-tensor theories --- are interesting phenomenological frameworks to describe deviations from general relativity in the strong-field regime. In these theories, the $N$-tuple of scalar fields takes values in a coordinate patch of an $N$-dimensional Riemannian target-space manifold whose properties are poorly constrained by weak-field observations. Here we introduce for simplicity a non-trivial model with two scalar fields and a maximally symmetric target-space manifold. Within this model we present a preliminary investigation of spontaneous scalarization for relativistic, perfect fluid stellar models in spherical symmetry. We find that the scalarization threshold is determined by the eigenvalues of a symmetric scalar-matter coupling matrix, and that the properties of strongly scalarized stellar configurations additionally depend on the target-space curvature radius. In preparation for numerical relativity simulations, we also write down the $3+1$ decomposition of the field equations for generic tensor-multi-scalar theories.Comment: 32 pages, 8 figures, 1 table, invited contribution to the Classical and Quantum Gravity Focus Issue "Black holes and fundamental fields". v3: version in press in CQG, with various improvements in response to the referees' comments. In particular, the 3+1 decomposition now allows for matte

Dreaming of a remittance house: understanding transnational housing aspirations

Migrant housing investments in the countries of origin are a demonstration of their transnational engagement and their potential contribution to local development. Yet, these investments remain relatively understudied on a large scale. In this paper, we explore three related questions on the drivers, prevalence, and development of transnational housing, drawing on an original survey of Ecuadorian and Indian migrants in different European cities. First, what factors account for the likelihood of migrants owning a remittance house? Second, for those migrants without houses abroad, what factors account for the likelihood of aspiring to have a remittance house in the first place, as opposed to “not being interested”? Third, how do factors affecting the likelihood of owning a remittance house compare to those affecting the likelihood of being a remittance house dreamer? Our findings suggest that, among those without a remittance house, the likelihood of being a transnational house dreamer decreases with the length of residence abroad, while the length of stay has no statistically significant impact on the likelihood of transnational house ownership. We also find that migrants with greater economic capacity are less likely to be dreamers and more likely to be transnational house-owners, suggesting that the difference between being a transnational house-dreamer and a transnational house-owner is often financial. Finally, greater attachment to the country of origin increases the likelihood of being both a transnational house owner and a transnational dreamer. We also discuss how the results change across migrant groups and across genders

Recruiting from the network: discovering Twitter users who can help combat Zika epidemics

Tropical diseases like \textit{Chikungunya} and \textit{Zika} have come to prominence in recent years as the cause of serious, long-lasting, population-wide health problems. In large countries like Brasil, traditional disease prevention programs led by health authorities have not been particularly effective. We explore the hypothesis that monitoring and analysis of social media content streams may effectively complement such efforts. Specifically, we aim to identify selected members of the public who are likely to be sensitive to virus combat initiatives that are organised in local communities. Focusing on Twitter and on the topic of Zika, our approach involves (i) training a classifier to select topic-relevant tweets from the Twitter feed, and (ii) discovering the top users who are actively posting relevant content about the topic. We may then recommend these users as the prime candidates for direct engagement within their community. In this short paper we describe our analytical approach and prototype architecture, discuss the challenges of dealing with noisy and sparse signal, and present encouraging preliminary results