Self-similar transmission properties of aperiodic Cantor potentials in gapped graphene

We investigate the transmission properties of quasiperiodic or aperiodic structures based on graphene arranged according to the Cantor sequence. In particular, we have found self-similar behaviour in the transmission spectra, and most importantly, we have calculated the scalability of the spectra. To do this, we implement and propose scaling rules for each one of the fundamental parameters: generation number, height of the barriers and length of the system. With this in mind we have been able to reproduce the reference transmission spectrum, applying the appropriate scaling rule, by means of the scaled transmission spectrum. These scaling rules are valid for both normal and oblique incidence, and as far as we can see the basic ingredients to obtain self-similar characteristics are: relativistic Dirac electrons, a self-similar structure and the non-conservation of the pseudo-spin. This constitutes a reduction of the number of conditions needed to observe self-similarity in graphene-based structures, see D\'iaz-Guerrero et al. [D. S. D\'iaz-Guerrero, L. M. Gaggero-Sager, I. Rodr\'iguez-Vargas, and G. G. Naumis, arXiv:1503.03412v1, 2015]

Don Juan y San Juan: María Zambrano en 1939

En este pequeño escrito se intenta esbozar el itinerario conceptual esencial seguido por el pensamiento de María Zambrano desde 1934 hasta 1939, pero ello solo con el fin de aproximarnos a una comprensión inicial de lo que a mi entender constituiría el núcleo filosófico de la obra Filosofía y poesía: el abrupto salto de Platón a San Juan de la Cruz, la reconciliación de filosofía y poesía en la mística.This small paper simply intends to outline the essential conceptual route followed by María Zambrano’s thought from 1934 till 1939. And this, so as to approach an initial understanding of what, to my view, would constitute the philosophical core of the book Philosophy and Poetry: that amazing jump from Plato to Saint Juan de la Cruz (that is to say, philosophy and poetry becoming reconciled in mysticism)

On the Extreme Positive Feedback Star-Forming Mode from Massive and Compact Superstar Clusters

The force of gravity acting within the volume occupied by young, compact and massive superstar clusters, is here shown to drive in situ all the matter deposited by winds and supernovae into several generations of star formation. These events are promoted by radiative cooling which drains the thermal energy of the ejected gas causing its accumulation to then rapidly exceed the gravitational instability criterion. A detailed account of the integrated ionizing radiation and mechanical luminosity as a function of time is here shown to lead to a new stationary solution. In this, the mass deposition rate $\dot M$, instead of causing a wind as in the adiabatic solution, turns into a positive feedback star-forming mode equal to the star formation rate. Some of the implications of this extreme positive feedback mode are discussed.Comment: 4 pages, 4 figures, accepted for publication in The Astrophysical Journal Letter