Artefacts in the digital era

Conferência realizada na Universidade Aberta em Lisboa, de 16-17 de novembro de 2018.Artefacts of the digital culture and art are digital or computerbased in essence. They aim at enhancing meaningful experiences to the observer/user/enjoyer alone or in groups. In their most striking essence, these artefacts are not only objects to be passively appreciated, but bring virtual characteristics, eventually immersive, boosting interaction, leading the user/enjoyer to embark on a journey of aesthetic contemplation of a polysemic nature. A meaningful experience occurs when the subject classifies it as relevant and rewarding, embracing various kinds of experiences (aesthetic-contemplative, educational, playful, entertaining, historical, social, etc.).info:eu-repo/semantics/publishedVersio

Breakdown of thermalization in finite one-dimensional systems

We use quantum quenches to study the dynamics and thermalization of hardcore bosons in finite one-dimensional lattices. We perform exact diagonalizations and find that, far away from integrability, few-body observables thermalize. We then study the breakdown of thermalization as one approaches an integrable point. This is found to be a smooth process in which the predictions of standard statistical mechanics continuously worsen as the system moves toward integrability. We establish a direct connection between the presence or absence of thermalization and the validity or failure of the eigenstate thermalization hypothesis, respectively.Comment: 9 pages, 13 figures, as publishe

On the BV formulation of boundary superstring field theory

We propose a Batalin-Vilkovisky (BV) formulation of boundary superstring field theory. The superstring field action is defined in terms of a closed one-form in the space of couplings, and we compute it explicitly for exactly solvable tachyon perturbations. We also argue that the superstring field action defined in this way is the partition function on the disc, in accord with a previous proposal.Comment: 11 pages, harvma