Intermittency at critical transitions and aging dynamics at edge of chaos

We recall that, at both the intermittency transitions and at the Feigenbaum attractor in unimodal maps of non-linearity of order $\zeta >1$, the dynamics rigorously obeys the Tsallis statistics. We account for the $q$-indices and the generalized Lyapunov coefficients $\lambda_{q}$ that characterize the universality classes of the pitchfork and tangent bifurcations. We identify the Mori singularities in the Lyapunov spectrum at the edge of chaos with the appearance of a special value for the entropic index $q$. The physical area of the Tsallis statistics is further probed by considering the dynamics near criticality and glass formation in thermal systems. In both cases a close connection is made with states in unimodal maps with vanishing Lyapunov coefficients.Comment: Proceedings of: STATPHYS 2004 - 22nd IUPAP International Conference on Statistical Physics, National Science Seminar Complex, Indian Institute of Science, Bangalore, 4-9 July 2004. Pramana, in pres

Parent-child relationship in student with and without difficulties of development

La forma de responder de los padres ante un niño con necesidades específicas de apoyo educativo, cuyas características son diferentes al resto, puede diferir de unos padres a otros. Este proceso de afrontamiento de la dificultad del niño es importante ya que la relación que los padres establezcan con sus hijos va a estar influenciada en parte por las reacciones y sentimientos que éstos desarrollen ante la dificultad de sus hijos pudiéndose producir tendencia al rechazo, indiferencia, percepciones alteradas de las cualidades y capacidades del hijo, problemas matrimoniales o injustificadas reacciones hacia la comunidad, sin olvidar el sentimiento de culpa (Nazir y Naz, 2012). Desde esta perspectiva, los objetivos que se plantean en el presente estudio son conocer las actitudes más frecuentes de los padres hacia sus hijos en términos de aceptación-rechazo y estilo educativo en función de las diferentes tipologías de sus hijos siendo estas: necesidades educativas especiales, otras necesidades específicas de apoyo educativo y sin dificultades de aprendizaje ni desarrollo y establecer una comparación entre ellas. Para ello, 75 familillas de alumnos de las diferentes tipologías han respondido al cuestionario Parental Acceptance-Rejection/Control Questionnaire (Rohner y Khaleque, 2005). Los resultados muestran diferencias en los sentimientos de aceptación-rechazo de los padres y sus estilos de control en función de las características tipológicas de sus hijos.How to respond to parent a child with special educational needs whose characteristics are different from the rest, you may differ from other parents. This process of coping with the difficulty of the child is important because the relationship that parents establish with their children will be influenced in part by the reactions and feelings they develop given the difficulty of their children being able to produce trend of rejection, indifference, altered perceptions of the qualities and abilities of the child, marital problems or unjustified reactions to the community, not to mention the guilt (Nazir and Naz, 2012). From this perspective, the objectives proposed in this study are to know the most common attitudes of parents towards their children in terms of acceptance-rejection and educational style based on the different types of children which are: special educational needs, other specific educational support and without learning and development and make a comparison between them. To do this, 75 students familiars of different types have responded to the questionnaire Parental Acceptance-Rejection / Control Questionnaire (Rohner and Khaleque, 2005). The results show differences in feelings of acceptance and rejection of parents and their styles of control depending on the typological characteristics of their children

A recent appreciation of the singular dynamics at the edge of chaos

We study the dynamics of iterates at the transition to chaos in the logistic map and find that it is constituted by an infinite family of Mori's $q$-phase transitions. Starting from Feigenbaum's $\sigma$ function for the diameters ratio, we determine the atypical weak sensitivity to initial conditions $\xi _{t}$ associated to each $q$-phase transition and find that it obeys the form suggested by the Tsallis statistics. The specific values of the variable $q$ at which the $q$-phase transitions take place are identified with the specific values for the Tsallis entropic index $q$ in the corresponding $\xi_{t}$. We describe too the bifurcation gap induced by external noise and show that its properties exhibit the characteristic elements of glassy dynamics close to vitrification in supercooled liquids, e.g. two-step relaxation, aging and a relationship between relaxation time and entropy.Comment: Proceedings of: Verhulst 200 on Chaos, Brussels 16-18 September 2004, Springer Verlag, in pres

Energías para un futuro sustentable: experencia en la feria de ciencia y arte -Cuatrociencia- de la Universidad Nacional de Córdoba

En el contexto de un crecimiento social inteligente y sustentable, el uso de la energía cumple un rol estratégico. Su uso se considera sustentable si la disponibilidad de un dado recurso energético está asegurada y su impacto ambiental sobre la naturaleza de su abastecimiento, transporte y uso es limitado. Este concepto se amplía como sustentabilidad inteligente, que consiste en una estrategia sistémica que busca la mayor eficiencia de la performance del sistema completo, considerando no solamente el funcionamiento de los componentes y subsistemas, sino del sistema como un todo. Aparecen entonces en el escenario las fuentes de energías sustentables, las cuales necesitan, en general, un vector energético para su aprovechamiento. Este consiste en sustancias o dispositivos que almacenan energía, de tal manera que ésta pueda liberarse posteriormente en forma controlada. Se pueden señalar tres grandes vectores energéticos: combustibles líquidos, electricidad (vía red o baterías) e hidrógeno, donde cada uno requiere de una infraestructura singular para su implementación. Asimismo es fundamental el conocimiento público de estos conceptos, para lo cual la difusión de estos temas de manera amplia es imprescindible para la sensibilización social. Con este objetivo se montó un stand mostrando dos maquetas interactivas, representando la matriz energética actual y futura sustentable, respectivamente. Se llevaron a cabo experiencias demostrativas con dos dipositivos. En uno se producía hidrógeno electrolítico mediante electricidad proveniente de paneles solares. Este hidrógeno se utilizó luego en una celda de combustible para producir electricidad y accionar con ella un dispositivo eléctrico. En un panel de fondo se expusieron ploteos, banners y videos explicativos y didácticos sobre la temática. También se contó con una cocina y un calefón solares. La experiencia fue muy positiva dado que los espectadores se interesaron mucho en la temática y se propone montar este stand durante la realización del HYFUSEN.http://www.hyfusen.com/libro.htmlFil: Robledo, C. B. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Físico Química de Córdoba; Argentina.Fil: Robledo, C. B. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Matemática y Física; Argentina.Fil: Bonafé, F. R. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Físico Química de Córdoba; Argentina.Fil: Bonafé, F. R. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Matemática y Física; Argentina.Fil: Sigal, A. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Robledo, J. I. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Subirada, P. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina.Fil: Moiraghi, B. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; Argentina.Fil: Rodríguez, R. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Matemática; Argentina.Otras Ciencias de la Tierra y relacionadas con el Medio Ambient

Universal renormalization-group dynamics at the onset of chaos in logistic maps and nonextensive statistical mechanics

We uncover the dynamics at the chaos threshold $\mu_{\infty}$ of the logistic map and find it consists of trajectories made of intertwined power laws that reproduce the entire period-doubling cascade that occurs for $\mu <\mu_{\infty}$. We corroborate this structure analytically via the Feigenbaum renormalization group (RG) transformation and find that the sensitivity to initial conditions has precisely the form of a $q$-exponential, of which we determine the $q$-index and the $q$-generalized Lyapunov coefficient $\lambda _{q}$. Our results are an unequivocal validation of the applicability of the non-extensive generalization of Boltzmann-Gibbs (BG) statistical mechanics to critical points of nonlinear maps.Comment: Revtex, 3 figures. Updated references and some general presentation improvements. To appear published as a Rapid communication of PR

Nonadditive entropy and nonextensive statistical mechanics - Some central concepts and recent applications

We briefly review central concepts concerning nonextensive statistical mechanics, based on the nonadditive entropy $S_q=k\frac{1-\sum_{i}p_i^q}{q-1} (q \in {\cal R}; S_1=-k\sum_{i}p_i \ln p_i)$. Among others, we focus on possible realizations of the $q$-generalized Central Limit Theorem, including at the edge of chaos of the logistic map, and for quasi-stationary states of many-body long-range-interacting Hamiltonian systems.Comment: 15 pages, 9 figs., to appear in Journal of Physics: Conf.Series (IOP, 2010

Feigenbaum graphs: a complex network perspective of chaos

The recently formulated theory of horizontal visibility graphs transforms time series into graphs and allows the possibility of studying dynamical systems through the characterization of their associated networks. This method leads to a natural graph-theoretical description of nonlinear systems with qualities in the spirit of symbolic dynamics. We support our claim via the case study of the period-doubling and band-splitting attractor cascades that characterize unimodal maps. We provide a universal analytical description of this classic scenario in terms of the horizontal visibility graphs associated with the dynamics within the attractors, that we call Feigenbaum graphs, independent of map nonlinearity or other particulars. We derive exact results for their degree distribution and related quantities, recast them in the context of the renormalization group and find that its fixed points coincide with those of network entropy optimization. Furthermore, we show that the network entropy mimics the Lyapunov exponent of the map independently of its sign, hinting at a Pesin-like relation equally valid out of chaos.Comment: Published in PLoS ONE (Sep 2011

The Carnegie Supernova Project I: photometry data release of low-redshift stripped-envelope supernovae

The first phase of the Carnegie Supernova Project (CSP-I) was a dedicated supernova follow-up program based at the Las Campanas Observatory that collected science data of young, low-redshift supernovae between 2004 and 2009. Presented in this paper is the CSP-I photometric data release of low-redshift stripped-envelope core-collapse supernovae. The data consist of optical (uBgVri) photometry of 34 objects, with a subset of 26 having near-infrared (YJH) photometry. Twenty objects have optical pre-maximum coverage with a subset of 12 beginning at least five days prior to the epoch of B-band maximum brightness. In the near-infrared, 17 objects have pre-maximum observations with a subset of 14 beginning at least five days prior to the epoch of J-band maximum brightness. Analysis of this photometric data release is presented in companion papers focusing on techniques to estimate host-galaxy extinction (Stritzinger et al., submitted) and the light-curve and progenitor star properties of the sample (Taddia et al., submitted). The analysis of an accompanying visual-wavelength spectroscopy sample of ~150 spectra will be the subject of a future paper.Comment: Updated a couple of small error

Demonstration of entanglement-by-measurement of solid state qubits

Projective measurements are a powerful tool for manipulating quantum states. In particular, a set of qubits can be entangled by measurement of a joint property such as qubit parity. These joint measurements do not require a direct interaction between qubits and therefore provide a unique resource for quantum information processing with well-isolated qubits. Numerous schemes for entanglement-by-measurement of solid-state qubits have been proposed, but the demanding experimental requirements have so far hindered implementations. Here we realize a two-qubit parity measurement on nuclear spins in diamond by exploiting the electron spin of a nitrogen-vacancy center as readout ancilla. The measurement enables us to project the initially uncorrelated nuclear spins into maximally entangled states. By combining this entanglement with high-fidelity single-shot readout we demonstrate the first violation of Bells inequality with solid-state spins. These results open the door to a new class of experiments in which projective measurements are used to create, protect and manipulate entanglement between solid-state qubits.Comment: 6 pages, 4 figure