arXiv subjects

Luis A. Nunez

Publications and source records attributed to Luis A. Nunez.

4 recordsLinked to original sources

arXiv2016

Cracking isotropic and anisotropic relativistic spheres

We explore the influence of density fluctuations on isotropic and anisotropic configurations, extending the concept of cracking for general relativistic fluid spheres. This concept, conceived to describe the behaviour of anisotropic matter distributions just after its departure from equilibrium, could provide some insight on potential instabilities and future evolution of relativistic fluids. We have refined the idea of cracking, considering local fluctuations --represented by any function of compact support defined in a closed interval-- and their effect on the state variables and their gradients through "barotropic" equations of state, $P = P(ρ)$ and $P_{\perp}= P_{\perp}(ρ)$. Under this approach it is found that both isotropic and anisotropic models could exhibit cracking (or overturning), and that previously crackable anisotropic models become uncrackable.

gr-qc↗

arXiv2015

Astroparticle Physics at Eastern Colombia

We present the emerging panorama of Astroparticle Physics at Eastern Colombia, and describe several ongoing projects, most of them related to the Latin American Giant Observatory (LAGO) Project. This research work is carried out at the Grupo de Investigaciones en Relatividad y Gravitación of Universidad Industrial de Santander.

astro-ph.IM↗

arXiv2010

Atomic data activities by the OP and IP consortia: past, present and new perspectives within the VAMDC

The Opacity Project (OP) and Iron Project (IP) are pioneering international collaborations which have been computing, for more than 25 years, massive atomic data sets for astrophysical applications. We review the data activities that have been carried out, namely curation, analysis and preservation, and the development of databases and computer tools for data dissemination and end-user processing. New opportunities within the current data-intensive boom referred to as e-science are described, in particular the Virtual Atomic and Molecular Data Center (VAMDC) that has been recently launched to consolidate and promote atomic and molecular database services. Key words: atomic data; Opacity Project; Iron Project; laboratory astrophysics; databases; e-science; virtual data centers.

astro-ph.SR↗

arXiv2008

ICT, Community Memory and Technological Appropriation

The core mission of universities and higher education institutions is to make public the results of their work and to preserve the collective memory of the institution. This includes the effective use of information and communication technologies (ICT) to systematically compile academic and research achievements as well as disseminate effectively this accumulated knowledge to society at large. Current efforts in Latin America and Venezuela in particular, are limited but provide some valuable insights to pave the road to this important goal. The institutional repository of Universidad de Los Andes (ULA) in Venezuela (www.saber.ula.ve) is such an example of ICT usage to store, manage and disseminate digital material produced by our University. In this paper we elaborate on the overall process of promoting a culture of content creation, publishing and preservation within ULA.

cs.DL↗