No abstract available

[en] Complex systems and nonlinear stochastic dynamics of dissipative open systems have attracted extensive research interest. Significant impacts have been made on a wide range of different areas including physics, biology, economics and social sciences. Challenges to a fundamental understanding are persisting, the seminar aims to cover both theoretical advances and cross-disciplinary applications.

[en] We present a general framework to construct criteria detecting genuinely multipartite entangled mixed quantum states in arbitrary-dimensional systems. We show that the resulting versatile set of criteria enables entanglement detection in systems, that had been unaccessible so far. They are experimentally implementable using local measurements without quantum state tomography and scale very favorably with system size. We then show how such a framework might be used to reveal even more about the structure of multipartite entanglement, e.g. detection of non k-separability and even possible classification. (author)

No abstract available

[en] Wikipedia as a web-based, collaborative, multilingual encyclopaedia project is a very suitable field to carry out research on social dynamics and to investigate the complex concepts of conflict, collaboration, competition, dispute, etc in a large community (∼26 Million) of Wikipedia users. The other face of Wikipedia as a productive society, is its output, consisting of (∼17) Millions of articles written unsupervised by unprofessional editors in more than 270 different languages. In this talk we report some analysis performed on Wikipedia in two different approaches: temporal analysis to characterize disputes and controversies among users and linguistic-based analysis to characterize linguistic features of English texts in Wikipedia. (author)

[en] The stochastic quantization method is a very elegant method to 2nd-quantize classical field theories. In this talk it is assumed that on a microscopic scale the noise of the Parisi-Wu approach of stochastic quantization is produced by a weakly coupled deterministic chaotic dynamics. Complex behavior arises that, if taken as an additional sector amending the standard model, distinguishes certain coupling constants as states of minimum vacuum energy. For weakly coupled Tchebyscheff maps one obtains a spectrum consistent with observed fundamental constants of the standard model. (author)

[en] We study the spreading of information in a mobile phone network by using time stamped data for an SI model. In spite of the fact that the aggregate network is a small world, the spreading is surprisingly slow. By using an appropriate set of null models we identify those correlations, which are mostly responsible for this slowing down: Topological correlations and their relation to the intensity of interactions, as well as the bursty character of activities. We give a detailed analysis of burstiness and conclude that none of the current models is able to describe the empirical findings. (author)

[en] Annihilation reactions, where the reactants are influenced by some external advective field, are one of the most simplest examples of nonlinear statistical systems. For this type of reaction in low space dimensions usual description by means of kinetic rate equation is not sufficient and the effect of density fluctuations must be taken into the account. Using perturbative renormalization group we study the influence of random velocity field on the kinetics of single-species annihilation reaction A +A → 0 at and below its critical dimension d_c=2. (author)

[en] We define a new class of random walk processes which maximize entropy. This maximal entropy random walk is equivalent to generic random walk if it takes place on a regular lattice, but it is not if the underlying lattice is irregular. In particular, we consider a lattice with weak dilution. We show that the stationary probability of finding a particle performing maximal entropy random walk localizes in the largest nearly spherical region of the lattice which is free of defects. This localization phenomenon, which is purely classical in nature, is explained in terms of the Lifshitz states of a certain random operator. (author)

[en] Intracellular signalling in general or genetic regulation and enzyme kinetics in specific are processes known to be of highly non linear nature. Yet, the idea of parsimony guides evolution of theory along the way of the simplest available models in sufficient agreement with experimental observations. Almost Linear Systems, - i.e. systems that follow a linear dynamic for the concentration of agents under the constraint that agent concentrations must be non-negative -, can be understood as a null-model of observed genetic regulation processes like for instance - the recruitment of various agents into functional protein complexes. In this way Almost Linear Systems provide a starting-point for a systematic identification of crucial non-linear agent interactions that defy linearization or can be used to predict the dynamics of agents missing in considered assays. (author)