Using complete measurement statistics for optimal device-independent randomness evaluation

The majority of recent works investigating the link between non-locality and randomness, e.g. in the context of device-independent cryptography, do so with respect to some specific Bell inequality, usually the CHSH inequality. However, the joint probabilities characterizing the measurement outcomes of a Bell test are richer than just the degree of violation of a single Bell inequality. In this work we show how to take this extra information into account in a systematic manner in order to optimally evaluate the randomness that can be certified from non-local correlations. We further show that taking into account the complete set of outcome probabilities is equivalent to optimizing over all possible Bell inequalities, thereby allowing us to determine the optimal Bell inequality for certifying the maximal amount of randomness from a given set of non-local correlations.Comment: 12 pages, 4 figures. v2, v3, v4: minor corrections. See also the related independent work arXiv:1309.389

Soft power and its audiences: Tweeting the Olympics from London 2012 to Sochi 2014

The ‘Tweeting the Olympics’ project (the subject of this special section of Participations) must be understood in the context of efforts by host states, the International Olympic Committee (IOC) and other actors involved in the Games to cultivate and communicate a set of meanings to audiences about both the Olympics events and the nations taking part. Olympic Games are not only sporting competitions; they are also exercises in the management of relations between states and publics, at home and overseas, in order to augment the attractiveness and influence or the soft power of the states involved. Soft power is most successful when it goes unnoticed according to its chief proponent Joseph Nye. If so, how can we possibly know whether soft power works? This article reviews the state of the field in thinking about public diplomacy, cultural diplomacy and soft power in the period of this project (2012-14), focusing particularly on how the audiences of soft power projects, like the London and Sochi Games, were conceived and addressed. One of the key questions this project addresses is whether international broadcasters such as the BBCWS and RT used social media during the Games to promote a cosmopolitan dialogue with global audiences and/or merely to integrate social media so as to project and shape national soft power. We argue first that the contested nature of the Olympic Games calls into question received theories of soft power, public and cultural diplomacy. Second, strategic national narratives during the Olympics faced additional challenges, particularly due to the tensions between the national and the international character of the Games. Third, the new media ecology and shift to a network paradigm further threatens the asymmetric power relations of the broadcasting paradigm forcing broadcasters to reassess their engagement with what was formerly known as ‘the audience’ and the targets of soft power

The christian project of emperors Maurice and Heraclius in the history of Theophylact Simocatta: Considerations on the narration and its purpose

Indexación: Scopus.En el presente trabajo se analiza la imagen del Imperio Romano en la Historia de Teofilacto Simocatta. En esta se identifica el uso de recursos narrativos que destacan a los emperadores Mauricio y Heraclio con un proyecto imperial cristiano común, exhibiendo virtudes y actitudes que el autor promueve a imitar y consolidar bajo su concepción escatológica y ecuménica.In the following paper the image of the Roman Empire is analyzed in the History of Theophylact Simocatta. In this, we note the use of narrative resources that highlight the Mauritius Emperor and Heraclius with a common Christian emperor’s imperial project, exhibiting virtues and attitudes that the author promotes role and consolidate under its eschatological and ecumenical conception.https://byzantion.uchile.cl/index.php/RBNH/article/view/4771

Optimal combined word-length allocation and architectural synthesis of digital signal processing circuits

Published versio

Assessing the Formation Scenarios for the Double Nucleus of M31 Using Two-Dimensional Image Decomposition

The double nucleus geometry of M31 is currently best explained by the eccentric disk hypothesis of Tremaine, but whether the eccentric disk resulted from the tidal disruption of an inbounding star cluster by a nuclear black hole, or by an m=1 perturbation of a native nuclear disk, remains debatable. I perform detailed 2-D decomposition of the M31 double nucleus in the Hubble Space Telescope V-band to study the bulge structure and to address competing formation scenarios of the eccentric disk. I deblend the double nucleus (P1 and P2) and the bulge simultaneously using five Sersic and one Nuker components. P1 and P2 appear to be embedded inside an intermediate component (r_e=3.2") that is nearly spherical (q=0.97+/-m0.02), while the main galaxy bulge is more elliptical (q=0.81+/-0.01). The spherical bulge mass of 2.8x10^7 M_sol is comparable to the supermassive black hole mass (3x10^7 M_sol). In the 2-D decomposition, the bulge is consistent with being centered near the UV peak of P2, but the exact position is difficult to pinpoint because of dust in the bulge. P1 and P2 are comparable in mass. Within a radius r=1\arcsec of P2, the relative mass fraction of the nuclear components is M_BH:M_bulge:P1: P2 = 4.3:1.2:1:0.7, assuming the luminous components have a common mass-to-light ratio of 5.7. The eccentric disk as a whole (P1+P2) is massive, M ~ 2.1x10^7 M_sol, comparable to the black hole and the local bulge mass. As such, the eccentric disk could not have been formed entirely out of stars that were stripped from an inbounding star cluster. Hence, the more favored scenario is that of a disk formed in situ by an m=1 perturbation, caused possibly by the passing of a giant molecular cloud, or the passing/accretion of a small globular cluster.Comment: 19 pages, 8 figures. AJ accepted. For the version of this paper with high resolution figures, go to: http://zwicky.as.arizona.edu/~cyp/work/m31.ps.g

Towards an Ashtekar formalism in eight dimensions

We investigate the possibility of extending the Ashtekar theory to eight dimensions. Our approach relies on two notions: the octonionic structure and the MacDowell-Mansouri formalism generalized to a spacetime of signature 1+7. The key mathematical tool for our construction is the self-dual (antiself-dual) four-rank fully antisymmetric octonionic tensor. Our results may be of particular interest in connection with a possible formulation of M-theory via matroid theory.Comment: 15 pages, Latex, minor changes, to appear in Class. Quantum Gra