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OALib Journal期刊

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Parcerias e coliga??es comunitárias: Potencialidades e desafios na cria??o de respostas articuladas
Vargas-Moniz,Maria; Morgado,José;
Análise Psicológica , 2010,
Abstract: the paper presents a panorama on the conceptual framework of partnerships and coalitions in community contexts and how these involve collaborative efforts among individuals, groups, organizations and communities. coalitions are seen privileged devices to activate local resources and problem solving that a single organization, service or group cannot autonomously solve or overcome. it is also an aim of this paper to present the role of coalitions within the crucial elements of community development. finally, there is an overview on the current research and evaluation in the field, and how there is an increasing body of scientific evidence concerning the several dimensions and factors relevant for the successful collaborative efforts implementation, involving issues such as social climate, structure, member involvement, and social change achievements.
FRW Cosmological Solutions in M-theory
Marco Cavaglia,Paulo Vargas Moniz
Physics , 2000,
Abstract: We present the canonical and quantum cosmological investigation of a four-dimensional, spatially flat, Friedmann-Robertson-Walker (FRW) model that is derived from the bosonic Neveu-Schwarz/Neveu-Schwarz sector of the low-energy M-theory effective action. We discuss in detail the phase space of the classical theory. We find the quantum solutions of the model and obtain the positive norm Hilbert space of states. Finally, the correspondence between wave functions and classical solutions is outlined.
Canonical and quantum FRW cosmological solutions in M-theory
Marco Cavaglia,Paulo Vargas Moniz
Physics , 2000, DOI: 10.1088/0264-9381/18/1/307
Abstract: We present the canonical and quantum cosmological investigation of a spatially flat, four-dimensional Friedmann-Robertson-Walker (FRW) model that is derived from the M-theory effective action obtained originally by Billyard, Coley, Lidsey and Nilsson (BCLN). The analysis makes use of two sets of canonical variables, the Shanmugadhasan gauge invariant canonical variables and the ``hybrid'' variables which diagonalise the Hamiltonian. We find the observables and discuss in detail the phase space of the classical theory. In particular, a region of the phase space exists that describes a four-dimensional FRW spacetime first contracting from a strong coupling regime and then expanding to a weak coupling regime, while the internal space ever contracts. We find the quantum solutions of the model and obtain the positive norm Hilbert space of states. Finally, the correspondence between wave functions and classical solutions is outlined.
Gauge field back-reaction in Born Infeld cosmologies
Paulo Vargas Moniz,John Ward
Physics , 2010, DOI: 10.1088/0264-9381/27/23/235009
Abstract: In this paper, we investigate the back-reaction of $U(1)$ gauge fields into a class of inflationary settings. To be more precise, we employ a Bianchi-I geometry (taken as an anisotropic perturbation of a flat FRW model) within two types of Born-Infeld theories. Firstly we consider pure Born-Infeld electromagnetism. For either a constant or a $b(\phi)$ coupling, inflationary trajectories are modified but anisotropies increase; In particular, for the former coupling we find that a quadratic inflaton potential, within a constant ratio for the scalar and gauge energy densities, does not induce sufficient inflation, while in the latter the back-reaction in the cosmology determines (from the tensor-scalar ratio) a narrow range where inflation can occur. A Dirac-Born-Infeld framework is afterwards analysed in both non-relativistic and relativistic regimes. In the former, for different cases of the coupling (richer with respect to mere BI setups) between scalar and gauge sectors, we find that inflationary trajectories are modified, with anisotropy increasing or decreasing. In particular, a tachyonic solution is studied, allowing for a non standard ratio between scalar and gauge matter densities, enhancing sufficient inflation, but with the anisotropy increasing. For the relativistic limit, inflationary trajectories are also modified and anisotropies increase faster than in the non-relativistic limit. Finally we discuss how magnetic seed fields could evolve in these settings.
Sentimento de comunidade, qualidade e satisfa??o de vida
Elvas,Susana; Moniz,Maria Jo?o Vargas;
Análise Psicológica , 2010,
Abstract: the perceived sense of community in a specific location, as in a residential neighbourhood, provides several benefits, both individual and community level. at the individual level, the greater the sense of community, greater participation in the community, the higher capital and social support received by the neighbourly relations and greater satisfaction and quality of life. at community level, the higher for the sense of identity and belonging, the greater community empowerment, promoting healthy and sustainable communities. in our study, the participants were children and adolescents, 15 from armador neighbourhood and 15 from alfama neighbourhood, with ages ranging from 7 to 15 that were making part in local projects of communitarian intervention. with this study, we evaluate this relation and the importance of a strong sense of belonging, identity with the place, to life satisfaction and quality of life, considering it as a efficacious strategy to promote community development.
Phantom-like behaviour in a brane-world model with curvature effects
Mariam Bouhmadi-Lopez,Paulo Vargas Moniz
Physics , 2008, DOI: 10.1103/PhysRevD.78.084019
Abstract: Recent observational evidence seems to allow the possibility that our universe may currently be under a dark energy effect of a phantom nature. A suitable effective phantom fluid behaviour can emerge in brane cosmology; In particular, within the normal non self-accelerating DGP branch, without any exotic matter and due to curvature effects from induced gravity. The phantom-like behaviour is based in defining an effective energy density that grows as the brane expands. This effective description breaks down at some point in the past when the effective energy density becomes negative and the effective equation of state parameter blows up. In this paper we investigate if the phantom-like regime can be enlarged by the inclusion of a Gauss-Bonnet (GB) term into the bulk. The motivation is that such a GB component would model additional curvature effects on the brane setting. More precisely, our aim is to determine if the GB term, dominating and modifying the early behaviour of the brane universe, may eventually extend the regime of validity of the phantom mimicry on the brane. However, we show that the opposite occurs: the GB effect seems instead to induce a breakdown of the phantom-like behaviour at an even smaller redshift.
Late-time acceleration in a brane with curvature effects
Mariam Bouhmadi-Lopez,Paulo Vargas Moniz
Physics , 2009, DOI: 10.1063/1.3141257
Abstract: In this paper we investigate if the phantom-like regime in the LDGP model can be enlarged by the inclusion of a Gauss-Bonnet (GB) term into the bulk. However, we show that the opposite occurs: the GB effect seems instead to induce a breakdown of the phantom-like behaviour at an even smaller redshift.
Higher order corrections to Heterotic M-theory inflation
Paulo Vargas Moniz,Sudhakar Panda,John Ward
Physics , 2009, DOI: 10.1088/0264-9381/26/24/245003
Abstract: We investigate inflation driven by $N$ dynamical five-branes in Heterotic M-theory using the scalar potential derived from the open membrane instanton sector. At leading order the resulting theory can be mapped to power law inflation, however more generally one may expect higher order corrections to be important. We consider a simple class of such corrections, which imposes tight bounds on the number of branes required for inflation.
On the thermal boundary condition of the wave function of the Universe
Mariam Bouhmadi-Lopez,Paulo Vargas Moniz
Physics , 2007,
Abstract: We broaden the domain of application of the recently proposed thermal boundary condition of the wave function of the Universe, which has been suggested as the basis of a dynamical selection principle on the landscape of string solutions.
Indefinite oscillators and black-hole evaporation
Claus Kiefer,Joao Marto,Paulo Vargas Moniz
Physics , 2008, DOI: 10.1002/andp.200910366
Abstract: We discuss the dynamics of two harmonic oscillators of which one has a negative kinetic term. This model mimics the Hamiltonian in quantum geometrodynamics, which possesses an indefinite kinetic term. We solve for the time evolution in both the uncoupled and coupled case. We use this setting as a toy model for studying some possible aspects of the final stage of black-hole evaporation. We assume that one oscillator mimics the black hole, while the other mimics Hawking radiation. In the uncoupled case, the negative term leads to a squeezing of the quantum state, while in the coupled case, which includes back reaction, we get a strong entangled state between the mimicked black hole and the radiation. We discuss the meaning of this state. We end by analyzing the limits of this model and its relation to more fundamental approaches.
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