## Novedades

**Reconocimientos y Premios**

**Julio de 2016**

El Lic. Federico Abellá fue presentado con un premio a Poster Distinguido (Distinguished Poster) en la **Hands-on School in Complex Systems School**: Página web de la conferencia. ¡Felicitaciones!

**Junio de 2016**

El Dr. Nicolás Rubido fue presentado con el Premio a Jóvenes Investigadores (Young Researchers Award) en la conferencia **XXXVI Dynamics Days Europe**: Página web de la conferencia. ¡Felicitaciones!

**Profesores visitantes**

**27 de Junio – 1 de Julio de 2016**

**Marcos G. Quiles**, Profesor Adjunto, Departamento de Ciencia y Tecnología (DCT), Universidad Federal de San Pablo (UNIFESP): Página web

###### 27 de Junio, 11:00hs – Salón de Seminarios, Instituto de Física, Facultad de Ciencias, UdelaR

**Título: **Community detection based on particle competition

**Resumen:** In this talk, we will present a dynamic community detection model based on particle competition. In this model, several particles walk in the network and compete with each other to mark their territory and reject particle intruders. The process reaches dynamics equilibrium when each network community has only one particle. Moreover, we will also show that the best results are achieved when the particle walking is not purely random, but a combination of random and greedy movement. Finally, by introducing a cooperative mechanism, we will point that the model can be applied to semi-supervised machine learning problems.

**3-10 de Diciembre de 2015**

**Dante R. Chialvo**, Investigador Principal del CONICET (Argentina), área Física, EMC3 Lab (Estudios Multidisciplinarioes en Complejidad y Ciencias del Cerebro): Página web

###### 4 de Diciembre, 14:30hs – Instituto de Matemática y Estadística “Rafael Laguardia”, Facultad de Ingeniería, UdelaR

**Título: **The brain is critical

**Resumen:** Systems which are near an edge between order and disorder behave differently. This intuitive notion led several of us to argue, two decades ago, that the most fundamental properties of the functioning brain are only feasible if it “somehow spontaneously locates itself” at the border of an instability. Supposedly, it is the mix of order and disorder, found generically at criticality, that allows the brain to be a brain. In this talk we review the motivations and then describe experimental results supporting this hypothesis both in health and disease, at various brain scales ranging from a few millimeters up to the entire brain cortex.

###### 9 de Diciembre, 15:00hs – Salón de seminarios del Instituto de Física, Facultad de Ciencias, UdelaR

**Título:** Complexity, Criticality, Contingency & Consciousness: what they all have in common and why we should care.

**Resumen:** Results in the area of statistical physics over the last decade shows the spontaneous emergence of Complexity from the interactions of simple components in a variety of systems, whether biological, social, behavioral, political, environmental or technological. Such emergence occurs more often near instabilities, in the boundaries between stable regimes, i.e. near Criticality. In this process of emergence, the idea of Contingent events appears, where small events from the past are judged a posteriori as triggers of unexpected catastrophes. This talk is dedicated to discuss how these three concepts can be understood by a unifying theoretical argument. We start discussing what is complexity in nature, continue with the hypothesis that complexity is always critical. After that, empirical results from large scale brain dynamics are used to advance the hypothesis that the brain is complex because is critical. Finally, our state of awareness (consciousness) is discussed presenting results which suggest that we are conscious whenever our brain is critical.

**16-25 de Noviembre de 2015**

**Rodrigo F. Pereira**, Profesor Adjunto, Departamento de Matemáticas, Universidad Tecnológica Federal del Paraná (UTFPR), PR, Brasil.

**Título:** Finite-time generalized high-order Lyapunov exponents for kicked double rotor

**Resumen: **The ordinary Lyapunov exponents spectrum describes the average exponential expansion/shrinkage rates of the axis of an infinitesimal ball around a trajectory under the temporal evolution of a dynamical system. These exponents are given by the linearization of the ruling equations. Due to intrinsic nonlinearities present in models that present chaotic dynamics, nonlinear effects, swept off by the linearization, can be crucial in elucidating details of the temporal evolution of such systems. Moreover, since Lyapunov exponents are dynamic invariants computed as an average over an ergodic trajectory, they are ”blind” about local/finite-time fluctuations present in typical chaotic dynamical systems. We present a detailed analysis of the finite-time fluctuations of the generalized high-order Lyapunov exponents for a physical system composed of a periodically kicked double rotor. We focus in its chaotic regime and in the transition from chaos to hyper-chaos as the intensity of the kicks is increased. Generalized high-order Lyapunov exponents are given by the analysis of high-order derivatives of the dynamical equations, which define linear mappings and their effects over the Lyapunov vectors are studied in a similar manner done for ordinary Lyapunov exponents. We study the temporal fluctuations of these high-order Lyapunov exponents for finite-time trajectories and relate their properties with those observed in the chaos / hiper-chaos transition.

**22-28 de Febrero de 2015**

**Rodrigo F. Pereira**, Profesor Adjunto, Departamento de Matemáticas, Universidad Tecnológica Federal del Paraná (UTFPR), PR, Brasil.

**Título:** Effective dynamics for time-varying networks

**Resumen: **In this talk I will review some of the recent developments on studying collective behaviour in networks of coupled chaotic systems, emphasizing on networks whose topology is time-dependent and how an effective static network can be obtained.