Light field integration in SUGRA theories

We revisit the integration of fields in N=1 Supergravity with the requirement that the effective theory has a reliable two-derivative supersymmetric description. In particular we study, in a supersymmetric manifest way, the situation where the fields that are mapped out have masses comparable to the Supersymmetry breaking scale and masses of the remaining fields. We find that as long as one stands in regions of the field configuration space where the analytic continuation to superspace of the F-flatness conditions be reliable equations of motion for the fields that are being mapped out, and provided their solutions are stable regardless the dynamics of the remaining fields, such a two-derivative description is a reliable truncation of the full effective theory. The study is mainly focused to models with two chiral sectors, H and L, described by a Kaehler invariant function with schematic dependencies of the form G=G_H(H,\bar H)+G_L(L,\bar L), which leads to a nearly decoupled theory that allows the previous requirements to be easily satisfied in a consistent way. Interestingly enough for the matters of our study this kind of models present an scenario that is as safe as the one presented in sequestered models. It is also possible to allow gauge symmetries as long as these appear also factorized in hidden and visible sectors. Then, the integration of the hidden vector superfields is compulsory and proceeds reliably through the D-flatness condition analytically continued to superspace.Comment: 20 pages. v2: references added, minor improvements and clarifications. v3: Conclusions slightly changed due to major clarifications. Abstract changed. References, two sections and an appendix added. v4: comment added about the space-time region for the results validity. Version acepted for plublicatio

On the structure of generalized toric codes

Toric codes are obtained by evaluating rational functions of a nonsingular toric variety at the algebraic torus. One can extend toric codes to the so called generalized toric codes. This extension consists on evaluating elements of an arbitrary polynomial algebra at the algebraic torus instead of a linear combination of monomials whose exponents are rational points of a convex polytope. We study their multicyclic and metric structure, and we use them to express their dual and to estimate their minimum distance

Strategy-proof mechanisms with monotonic preferences: The case of pure public goods economies

This paper explores a typical public finance problem where there are m public goods (education, transportation, police, etc.) provided in limited amounts due to budget constraints, and where individual's preferences are not known. It is shown that all institutions (i.e., decision mechanisms) available to decide the allocation of goods have very unattractive properties: either the decision mechanisms are not compatible with individual's incentives, or they are dictatorial (i.e, they are based on a single individual's preferences)

A counterexample for Improved Sobolev Inequalities over the 2-adic group

On the framework of the 2-adic group Z_2, we study a Sobolev-like inequality where we estimate the L^2 norm by a geometric mean of the BV norm and the Besov space B(-1,\infty,\infty) norm. We first show, using the special topological properties of the p-adic groups, that the set of functions of bounded variations BV can be identified to the Besov space B(1,\infty,1). This identification lead us to the construction of a counterexample to the improved Sobolev inequality.Comment: 10