A Monopole Near a Black Hole

We study an electric charge held at rest outside a magnetically charged black hole. We find that even if the electric charge is treated as a perturbation on a spherically symmetric magnetic Reissner-Nordstrom hole, the geometry at large distances is that of a magnetic Kerr-Newman black hole. When the charge approaches the horizon and crosses it, the exterior geometry becomes that of a Kerr-Newman hole with electric and magnetic charges and with total angular momentum given by the standard value for a charged monopole pair. Thus, in accordance with the "no-hair theorem", once the charge is captured by the black hole, the angular momentum associated with the charge monopole system, looses all traces of its exotic origin and it is perceived from the outside as common rotation. It is argued that a similar analysis performed on Taub-NUT space should give the same result, namely, if one holds an ordinary mass outside of the horizon of a Taub-NUT space with only magnetic mass, the system, as seen from large distances, is endowed with an angular momentum proportional to the product of the two kinds of masses. When the ordinary, electric, mass reaches the horizon, the exterior metric becomes that of a rotating Taub-NUT space.Comment: 8 pages. References adde

Unlocking Value Creation Using an Agritourism Business Model

Agritourism has achieved a greater importance in the last decade, but despite this relevance, the definition is not aligned everywhere, depending on the contingency variables of the context in which agritourism is located. This paper aims at analyzing the business model’s key success factors of Italian agritourism by studying their structural, social and economic features, integrated with a sustainability approach. The empirical analysis is based on a sample of agritourism, located in an Italian region. The empirical results show relevant and useful elements to support the sustainable development of agritourism business models in Italy, linking theory, policy and practices. Indeed, these results, together with others related to the economic dimension of the farms, their specialization, and the characteristics of the farmers make it possible to argue that there are common elements, which offer potential for agritourism. In addition, it was possible to identify two different models of agritourism. Agritourism can open new horizons in rural sustainable development, with possible beneficial effects on the environment, society, agricultural heritage and economic growth. In particular, regional policy developers should take into consideration these elements in order to direct correctly efforts. The research shows also some interesting theoretical implications as it contributes to enrich the literature on this particular kind of business model. At the same time, it helps family owners to increase the overall understanding of their agritourism, in order to finalize adequate planning and communication