New solutions of the D-dimensional Klein-Gordon equation via mapping onto the nonrelativistic one-dimensional Morse potential

New exact analytical bound-state solutions of the D-dimensional Klein-Gordon equation for a large set of couplings and potential functions are obtained via mapping onto the nonrelativistic bound-state solutions of the one-dimensional generalized Morse potential. The eigenfunctions are expressed in terms of generalized Laguerre polynomials, and the eigenenergies are expressed in terms of solutions of irrational equations at the worst. Several analytical results found in the literature, including the so-called Klein-Gordon oscillator, are obtained as particular cases of this unified approac

Transmission coefficient and two-fold degenerate discrete spectrum of spin-1 bosons in a double-step potential

The scattering of spin-1 bosons in a nonminimal vector double-step potential is described in terms of eigenstates of the helicity operator and it is shown that the transmission coefficient is insensitive to the choice of the polarization of the incident beam. Poles of the transmission amplitude reveal the existence of a two-fold degenerate spectrum. The results are interpreted in terms of solutions of two coupled effective Schr\"{o}dinger equations for a finite square well with additional $\delta$-functions situated at the borders.Comment: arXiv admin note: substantial text overlap with arXiv:1203.119

Gravitational Wave Signatures of Highly Magnetized Neutron Stars

Motivated by the recent gravitational wave detection by the LIGO-VIRGO observatories, we study the Love number and dimensionless tidal polarizability of highly magnetized stars. We also investigate the fundamental quasi-normal mode of neutron stars subject to high magnetic fields. To perform our calculations we use the chaotic field approximation and consider both nucleonic and hyperonic stars. As far as the fundamental mode is concerned, we conclude that the role played by the constitution of the stars is far more relevant than the intensity of the magnetic field and if massive stars are considered, the ones constituted by nucleons only present frequencies somewhat lower than the ones with hyperonic cores, a feature that can be used to point out the real internal structure of neutron stars. Moreover, our studies clearly indicate that strong magnetic fields play a crucial role in the deformability of low mass neutron stars, with possible consequences on the interpretation of the detected gravitational waves signatures.Comment: 24 pages, 4 figures, 6 table

Bound states of bosons and fermions in a mixed vector-scalar coupling with unequal shapes for the potentials

The Klein-Gordon and the Dirac equations with vector and scalar potentials are investigated under a more general condition, $V_{v}+V_{s}= \mathrm{constant}$. These intrinsically relativistic and isospectral problems are solved in a case of squared hyperbolic potential functions and bound states for either particles or antiparticles are found. The eigenvalues and eigenfuntions are discussed in some detail and the effective Compton wavelength is revealed to be an important physical quantity. It is revealed that a boson is better localized than a fermion when they have the same mass and are subjected to the same potentials.Comment: 3 figure

Street Flowers: Urban Survivors of the Privileged Land Conference Paper

I have presented papers about Street Flowers: Urban Survivors of the Privileged Land at 'Duration’ - an international, interdisciplinary conference exploring the temporality of contemporary public arts practice

Diversity in the maps of a Lisbon neighbourhood: community and ‘official’ discourses about the renewed Mouraria

The neighbourhood of Mouraria in the center of Lisbon is today home to three main groups of residents: traditional residents, new gentrifiers, and immigrants. This diversity is simultaneously a strength of and a threat to its social cohesion and its current urban rehabilitation process, undertaken by the City Council of Lisbon (CCL). This study has three main goals: 1) to analyze how the ‘community identity’ maps of the neighbourhood are constructed by residents’ discourse; 2) to analyze how the ‘official’ cultural map of the neighbourhood is constructed in the discourses of the press and the CCL; and 3) to compare the ‘official’ and the ‘community’ maps. In drafting the ‘community’ maps, 22 interviews were conducted with traditional residents (14), new gentrifiers (6), and immigrants (2). The ‘official’ cultural map was re-constructed through a press analysis (four articles from two reference newspapers: Público, 2014; Expresso, 2013) and an in-depth interview with the coordinator of the CCL office in Mouraria. Findings show that the rehabilitation program is represented in the ‘official’ discourse in a more positive way than in residents’ discourses. The main divergence concerns the targets of the intervention. However, in both discourses there is agreement regarding the social problems of Mouraria. The stories of the past told by traditional residents, although mentioning the loss of the traditional character of Mouraria, show the importance of public spaces for place attachment and place identity. The discourses of new residents highlight the role of places in building connections between past and present, and in helping maintain a sense of continuity. We discuss the importance of community identity mapping in understanding the ‘battle of ideas’ around urban rehabilitation and the impact that different perspectives can have. The study can be a source of information for decision-makers, helping strengthen the communication bridge between them and the community.info:eu-repo/semantics/publishedVersio

Sheep Grazing Patterns for Better Land Management: Adjusting GPS Tracking Protocol

Small ruminant livestock systems in northeast Portugal are an extensive activity based on daily grazing paths across the landscape. The flocks use multiple patches of multiple land cover types in different ways throughout the year. Shepherd and flock interactions determine the resting and feeding spots utilized by sheep and goats according to the biotic and abiotic conditions. Information about the herding home range is central to managing the land use and vegetation cover and optimizing sheep and goats\u27 productivity in traditional systems. This study\u27s main objective is to contribute to calibrate a shepherding GPS protocol to monitor sheep flocks based on fieldwork in Vimieiro (Mirandela) on a protected area of the European Natura 2000 network. We answer two farmers\u27 and breeders\u27 requests for using GPS collars to monitor the landscape usage by sheep: (1) How closely do collared sheep remain within the flock? (2) How do the collars perform on different logging frequencies to estimate patch occupancy? We analyzed the grazing paths based on three collars\u27 5-minute GPS positions from winter to summer solstices. We investigated the differences in extent, duration, and frequency data of each collar throughout the season change based on spatial regressions. Results show no significant differences among the three collars ranges. It also indicates that positions collected every 15 and 30 minutes could be adequate. It means that a flock monitoring low cost can be generalized, providing accurate information to manage the pastoral territory and increase the small ruminant\u27s productivit