Dark particle mass effects on neutron star properties from a short-range correlated hadronic model

In this work we study a relativistic mean-field (RMF) hadronic model, with nucleonic short-range correlations (SRC) included, coupled to dark matter (DM) through the Higgs boson. We study different parametrizations of this model by running the dark particle Fermi momentum, and its mass in the range of $50$ GeV $\leqslant M_\chi\leqslant 500$ GeV, compatible with experimental spin-independent scattering cross-sections. By using this RMF-SRC-DM model, we calculate some neutron star quantities, namely, mass-radius profiles, dimensionless tidal deformabilities, and crustal properties. Our findings show that is possible to construct RMF-SRC-DM parametrizations in agreement with constraints provided by LIGO and Virgo collaboration (LVC) on the GW170817 event, and recent observational data from the NICER mission. Furthermore, we show that the increase of $M_\chi$ favors the model to attain data from LVC regarding the tidal deformabilities. Higher values of $M_\chi$ also induce a reduction of the neutron star crust (mass and thickness), and cause a decrease of the crustal fraction of the moment of inertia ($I_{\rm{\tiny crust}}/I$). Nevertheless, we show that some RMF-SRC-DM parametrizations still exhibit $I_{\rm{\tiny crust}}/I>7\%$, a condition that explains the glitch activity in rotation-powered pulsars such as the Vela one. Therefore, dark matter content can also be used for describing such a phenomenon.Comment: 10 pages, 8 figures. Published in Monthly Notices of the Royal Astronomical Societ

Recent astrophysical observations reproduced by a short-range correlated van der Waals-type model?

We perform an improvement in a van der Waals-type model by including it effects of short-range correlations (SRC). Attractive and repulsive parts of the nucleon-nucleon interaction are assumed to be density-dependent functions, more specifically, we adopt the Carnahan-Starling (CS) method for the latter, and a suitable expression for the former in order to reproduce the structure of the Clausius (C) real gas model. The parametrizations of the resulting model, named as CCS-SRC model, are shown to be capable of reproducing the flow constraint at the high-density regime of symmetric nuclear matter for incompressibility values inside the range of $K_0=(240\pm 20)$ MeV. In the context of stellar matter, our findings point out a good agreement of the CCS-SRC model with recent astrophysical observational data, namely, mass-radius contours and dimensionless tidal deformability regions and values, coming from gravitational waves data related to the GW170817 and GW190425 events, and from the NASA's Neutron star Interior Composition Explorer (NICER) mission. Furthermore, the values for the symmetry energy slope of the model ($L_0$) are in agreement with a recent range found for this quantity, claimed to be consistent with results reported by the updated lead radius experiment (PREX-2) collaboration. In this case, higher values of $L_0$ are favored, while the opposite scenario does not allow simultaneous compatibility between the model and the astrophysical data.Comment: 9 pages, 11 figure

Common damages and recommendations for the seismic retrofitting of vernacular dwellings

This closure chapter acknowledges the most common retrofitting elements and measures identified in vernacular architecture. It enhances common systematic structural damage and failure mechanisms during earthquakes, relating them with probable causes, and establishing general recommend ations to consider in preventive and reactive actions. Also, recommendations for the design and detailing of new construction in prone earthquake areas are advancedPortuguese Science and Technology Foundation (FCT) to the research project ‘SEISMIC - V – Vernacular Seismic Culture in Portugal’ (PTDC/ATP - AQI/ 3934/2012

Efeitos da idade de corte na produção e valor nutritivo do capim quicuio-da-amazônia em quatro épocas do ano.

bitstream/item/59118/1/CPATU-ComTec39.pd

Suplementação alimentar com resíduos da agroindústria em bubalinos na fase de crescimento.

bitstream/item/59257/1/CPATU-ComTec44.pd