Multifrequency study of a new Hybrid Morphology Radio Source

Hybrid Morphology Radio Sources (HyMoRS) are a class of radio galaxies having the lobe morphology of a Fanaroff-Riley (FR) type I on one side of the active nucleus and of a FR type II on the other. The origin of the different morphologies between FR I and FR II sources has been widely discussed in the past 40 years, and HyMoRS may be the best way to understand whether this dichotomy is related to the intrinsic nature of the source and/or to its environment. However, these sources are extremely rare (<1% of radio galaxies) and only for a few of them a detailed radio study, that goes beyond the morphological classification, has been conducted. In this paper we report the discovery of one new HyMoRS; we present X-ray and multi-frequency radio observations. We discuss the source morphological, spectral and polarisation properties and confirm that HyMoRS are intrinsically bimodal with respect to these observational characteristics. We notice that HyMoRS classification based just on morphological properties of the source is hazardous.Comment: 8 pages, 9 figures, accepted MNRA

Perturbations of the asymptotic region of the Schwarzschild-de Sitter spacetime

The conformal structure of the Schwarzschild-de Sitter spacetime is analysed using the extended conformal Einstein field equations. To this end, initial data for an asymptotic initial value problem for the Schwarzschild-de Sitter spacetime is obtained. This initial data allows to understand the singular behaviour of the conformal structure at the asymptotic points where the horizons of the Schwarzschild-de Sitter spacetime meet the conformal boundary. Using the insights gained from the analysis of the Schwarzschild-de Sitter spacetime in a conformal Gaussian gauge, we consider nonlinear perturbations close to the Schwarzschild- de Sitter spacetime in the asymptotic region. We show that small enough perturbations of asymptotic initial data for the Schwarzschild de-Sitter spacetime give rise to a solution to the Einstein field equations which exists to the future and has an asymptotic structure similar to that of the Schwarzschild-de Sitter spacetime.Comment: Accepted version in Ann. Henri Poincar\'e. Title change: "Conformal properties of the Schwarzschild-de Sitter spacetime" to "Perturbations of the asymptotic region of the Schwarzschild-de Sitter spacetime". Sections reorganised. 64 pages, 10 figure

Systems of State-Owned Enterprises: from Public Entrepreneurship to State Shareholding

This thesis outlines a new analytical perspective on state ownership through the original concept of systems of state-owned enterprises (SOSOEs). It is argued that the SOSOEs concept adequately captures the evolution of state-owned enterprises (SOEs) in modern capitalist economies, challenging and enriching existing economic theories as well as contributing to reinstate the policy instrumentality of state ownership. The concept is defined from a comparative case study analysis of two distinct SOSOEs, operating within the same national context in different time periods. The first case concerns the Istituto per la Ricostruzione Industriale (IRI), Italy’s former and most relevant state holding company, that played a central role in the Country’s post-WWII economic development. This thesis advances an interpretation of IRI’s economic function based on an original empirical investigation of its archival and documentary sources, focusing on its main public policy missions and on its display of industrial entrepreneurship features. The second case examines the current Italian system of SOEs, assessing the still relevant presence of SOEs in the Italian national context and evaluating the overall governance of the system through a set of interviews with leading executives. Despite the similarity in size and sectoral diversification, the two SOSOEs differ significantly in terms of their operating configurations. In fact, they could be assimilated to two dichotomous ideal types: the IRI SOSOEs represents a template for the policy-oriented and dynamic ‘public entrepreneurship’ model, while the current Italian SOSOEs resembles the policy-neutral and passive ‘state shareholding’ variant. Implicit in these results is the opportunity for current SOSOEs to embrace a public entrepreneurship configuration, in order to exploit the full policy potential of state ownership in driving economic change. The thesis concludes with a proposal for reforming Italy’s current SOSOEs via the creation of a state holding company

Polyhomogeneous spin-0 fields in Minkowski spacetime

The asymptotic behaviour of massless spin-0 fields close to spatial and null infinity in Minkowski spacetime is studied by means of Friedrich's cylinder at spatial infinity. The results are applied to a system of equations called the good-bad-ugly which serves as a model for the Einstein field equations in generalised harmonic gauge. The relation between the logarithmic terms (polyhomogeneity) appearing in the solution obtained using conformal methods and those obtained by means of a heuristic method based on H\"ormander's asymptotic system is discussed. This review article is based on Class. Quantum Grav. 40 055002 and arXiv:2304.11950.Comment: 17 pages, submitted to Philosophical Transactions A (At the interface of asymptotics, conformal methods and analysis in general relativity

Les villes des nouveaux Länder : La requalification dans le difficile contexte du déclin

La question de la requalification des friches dans les villes des nouveaux Länder allemands se joue dans une situation démographique difficile, qu’accompagne un contexte économique peu favorable. Les friches sont nombreuses, et d’autres vont venir s’ajouter au fur et à mesure des nécessaires démolitions : on comprend alors la nécessité pour les acteurs d’intégrer la question des friches dans un processus global de restructuration du tissu urbain. Les marges de manoeuvre sont faibles pour tous les acteurs, qui doivent coordonner des intérêts parfois difficilement conciliables : la transformation du bâti urbain est donc un processus lent, de longue haleine.The matter of retraining urban wasteland in german new Länder towns happens to occur at a time when demography is faced with a sharp drop. This is underscored by unfavourable economic conditions at that. There are plenty of urban wasteland and many others are looming because of the demolition work that needs to be done. One understands then how necessary it is for the participants to integrate the matter of urban wasteland into the process of urban tissue restructuring. The whole participants have little room for manoeuvre the more so as conflicting interests make it difficult to reach a compromise : the rehabilitation of urban tissue is therefore a slow, a long-term process

LLAGN and jet-scaling probed with the EVN

Accreting black holes on all mass scales (from stellar to supermassive) appear to follow a nonlinear relation between X-ray luminosity, radio luminosity and BH mass, indicating that similar physical processes drive the central engines in X-ray binaries and active galactic nuclei (AGN). However, in recent years an increasing number of BH systems have been identified that do not fit into this scheme. These outliers may be the key to understand how BH systems are powered by accretion. Here we present results from EVN observations of a sample of low-luminosity AGN (LLAGN) with known mass that have unusually high radio powers when compared with their X-ray luminosity.Comment: Presented at the 11th EVN Symposium, Bordeaux, France, 2012 October 9-12. Six pages, including a figure and a table. Final, accepted versio