Positive operator valued measures covariant with respect to an irreducible representation

Given an irreducible representation of a group G, we show that all the covariant positive operator valued measures based on G/Z, where Z is a central subgroup, are described by trace class, trace one positive operators.Comment: 9 pages, Latex2

The winds and coronae of early-type stars

The properties of the winds of hot stars as derived from radio, ultraviolet and X-ray observations is presented. Special focus is given to observations that test line driven wind theory. In this theory the wind properties are determined by the stellar effective temperature and surface gravity, but not parameters that specify the mechanical or wave fluxes from the star. Alternate explanations of the X-ray emission from the early-type stars are discussed. Evidence is given for the presence of coronal zones at the base of the stellar winds

Super G-spaces

We review the basic theory of super $G$-spaces. We prove a theorem relating the action of a super Harish-Chandra pair $(G_0, \mathfrak{g})$ on a supermanifold to the action of the corresponding super Lie group $G$. The theorem was stated in [DM99] without proof. The proof given here does not use Frobenius theorem but relies on Koszul realization of the structure sheaf of a super Lie group (see [Kosz83]). We prove the representability of the stability subgroup functor

Position and momentum observables on R and on R^3

We characterize all position and momentum observables on R and on R^3. We study some of their operational properties and discuss their covariant joint observables.Comment: 18 page

Using Data Envelopment Analysis to Evaluate Environmentally Conscious Tourism Management

This paper discusses a methodology to assess the performances of tourism management of local governments when economic and environmental aspects are considered as equally relevant. In particular, the focus is on the comparison and efficiency assessment of Italian municipalities located on the costal areas. In order to assess the efficiency status of the considered management units, Data Envelopment Analysis (DEA), a methodology for evaluating the relative efficiency of decision making units, is applied. The efficiency index measure used in DEA analysis accounts for both environmental and economic features correlated to the tourism industry. Further, potential managerial improvements for those areas resulting far from the efficiency frontier can be investigated.Data envelopment analysis, Sustainable tourism

Benchmarking in Tourism Destination, Keeping in Mind the Sustainable Paradigm

Tourism destination benchmarking and the assessment of tourism management performances are a crucial and challenging task in the direction of evaluating tourism sustainability and reshaping tourism activities. However, assessing tourism management efficiency per se may not provide enough information concerning long-term performances, which is what sustainability is about. Natural resources management should therefore be included in the analysis to provide a more exhaustive picture of long-run sustainable efficiency and tourism performances. Indeed, while the environmental endowment of a site is a key feature in tourism destination comparison, what really matters is its effective management. Therefore, in this paper we assess and compare tourism destinations, not only in terms of tourism services supply, but also in terms of the performance of environmental management. The proposed efficiency assessment procedure is based on Data Envelopment Analysis (DEA). DEA is a methodology for evaluating the relative efficiency when facing multiple input and output. Although the methodology is extremely versatile, for the sake of exemplification, in this paper it is applied to the valuation of sustainable tourism management of the twenty Italian regions.Data envelopment analysis, Sustainable tourism indicators