Poisson Sigma Model with branes and hyperelliptic Riemann surfaces

We derive the explicit form of the superpropagators in presence of general boundary conditions (coisotropic branes) for the Poisson Sigma Model. This generalizes the results presented in Cattaneo and Felder's previous works for the Kontsevich angle function used in the deformation quantization program of Poisson manifolds without branes or with at most two branes. The relevant superpropagators for n branes are defined as gauge fixed homotopy operators of a complex of differential forms on n sided polygons P_n with particular "alternating" boundary conditions. In presence of more than three branes we use first order Riemann theta functions with odd singular characteristics on the Jacobian variety of a hyperelliptic Riemann surface (canonical setting). In genus g the superpropagators present g zero modes contributions.Comment: 26 pages, 3 figures. Notation fixed, Section 6.1 and Appendix C shortened, two references adde

Invariant Gibbs measures of the energy for shell models of turbulence; the inviscid and viscous cases

Gaussian measures of Gibbsian type are associated with some shell models of 3D turbulence; they are constructed by means of the energy, a conserved quantity for the 3D inviscid and unforced shell model. We prove the existence of a unique global flow for a stochastic viscous shell model and a global flow for the deterministic inviscid shell model, with the property that these Gibbs measures are invariant for these flows

An Analysis of the Notion of Need for the Representation of Public Services

Many Public Administrations structure their services around the notion of users’ need. However, there is a gap between private, subjectively perceived needs (self-attributed) and needs that are attributed by PA to citizens (heteroattributed). Because of the gap, citizens’ needs are often only partially satisfied by PAs services. This gap is in part due to the fact that the meaning of the word “need” is ambiguous and full of antinomic nuances. The purpose of this paper is to formulate a definition of “need” suitable for citizens’ needs management with respect to PA’s services offering, and to provide an accurate ontological analysis of the notion of “need” and the network of concepts that relate to it