Tri-bimaximal and bimaximal neutrino mixing from discrete symmetries

The neutrino oscillation data are well explained by the tri-bimaximal pattern. Recently it has been shown that also the bimaximal pattern could be a very good starting point in order to describe the lepton mixing. In this paper I review both the flavour structures and then I present an explicit example.Comment: 4 pages; Talk given at IFAE 2009: Incontri di Fisica delle Alte Energie, Bari, Italy, 15-17 April 200

Leibniz and the Problem of Temporary Truths

Not unlike many contemporary philosophers, Leibniz admitted the existence of temporary truths, true propositions that have not always been or will not always be true. In contrast with contemporary philosophers, though, Leibniz conceived of truth in terms of analytic containment: on his view, the truth of a predicative sentence consists in the analytic containment of the concept expressed by the predicate in the concept expressed by the subject. Given that analytic relations among concepts are eternal and unchanging, the problem arises of explaining how Leibniz reconciled one commitment with the other: how can truth be temporary, if concept-containment is not? This paper presents a new approach to this problem, based on the idea that a concept can be consistent at one time and inconsistent at another. It is argued that, given a proper understanding of what it is for a concept to be consistent, this idea is not as problematic as it may seem at first, and is in fact implied by Leibniz’s general views about propositions, in conjunction with the thesis that some propositions are only temporarily true

Dark matter within the minimal flavour violation ansatz

Minimal Flavour Violation hypothesis can provide an attractive framework for Dark Matter (DM). We consider scalar DM candidates carrying flavour quantum numbers and whose representation under the flavour group guarantees DM stability. They interact with the Standard Model fields through Higgs portal at renormalisable level and also to quarks through dimension-6 operators. We provide a systematic analysis of the viable parameter space for the DM fields, which are triplet of the flavour group, considering several DM-quark interactions. In this framework, we analyse in which cases the viable parameter space differs from Higgs portal models thanks to the underlying flavour structure. In contrast to minimal Higgs portal scenarios, we find that light DM in the GeV mass range as well as heavier candidates above Higgs resonance could be allowed by colliders, direct and indirect DM detection searches as well as flavour constraints. The large mass regime above the top mass could even be beyond the reach of future experiments such as Xenon 1T.Comment: 11 pages, 2 figures; v2: references added, version published on Phys.Lett.

Political Careers or Career Politicians?

Two main career paths are prevalent among politicians in modern democracies: there are career politicians (i.e., politicians who work in the political sector until retirement), and political careers (i.e., there are politicians who leave politics before retirement and work in the private sector). In this paper, we propose a dynamic equilibrium model of the careers of politicians in a political economy with a private sector and a political sector, where individuals are heterogeneous with respect to their market ability and political skills. We characterize the conditions under which the two career paths emerge in equilibrium, and investigate the effects of monetary incentives and other features of the political-economic environment on the quality of politicians and their careers. Our analysis also provides a rationale for the existence and the survival of political parties.politicians, parties, careers in politics

Majority Rule in a Stochastic Model of Bargaining

In this paper we consider multilateral stochastic bargaining models with general agreement rules. For n-player games where in each period a player is randomly selected to allocate a stochastic level of surplus and qNONCOOPERATIVE BARGAINING; VOTING RULES; STOCHASTIC GAMES