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Jun 30, 2018
06/18

by
Filippo Radicchi

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We consider different methods, that do not rely on numerical simulations of the percolation process, to approximate percolation thresholds in networks. We perform a systematic analysis on synthetic graphs and a collection of 109 real networks to quantify their effectiveness and reliability as prediction tools. Our study reveals that the inverse of the largest eigenvalue of the non-backtracking matrix of the graph often provides a tight lower bound for true percolation threshold. However, in...

Topics: Physics, Physics and Society, Statistical Mechanics, Condensed Matter

Source: http://arxiv.org/abs/1412.3678

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0.0

Jun 30, 2018
06/18

by
Filippo Radicchi

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Power-law distributions are typical macroscopic features occurring in almost all complex systems observable in nature. As a result, researchers in quantitative analyses must often generate random synthetic variates obeying power-law distributions. The task is usually performed through standard methods that map uniform random variates into the desired probability space. Whereas all these algorithms are theoretically solid, in this paper we show that they are subject to severe machine-dependent...

Topics: Physics, Computation, Statistics, Statistical Mechanics, Physics and Society, Condensed Matter

Source: http://arxiv.org/abs/1405.0058

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2.0

Jun 27, 2018
06/18

by
Filippo Radicchi

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The function of a real network depends not only on the reliability of its own components, but is affected also by the simultaneous operation of other real networks coupled with it. Robustness of systems composed of interdependent network layers has been extensively studied in recent years. However, the theoretical frameworks developed so far apply only to special models in the limit of infinite sizes. These methods are therefore of little help in practical contexts, given that real...

Topics: Condensed Matter, Statistical Mechanics, Physics and Society, Physics

Source: http://arxiv.org/abs/1503.04655

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0.0

Jun 29, 2018
06/18

by
Filippo Radicchi; Claudio Castellano

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Theoretical attempts proposed so far to describe ordinary percolation processes on real-world networks rely on the locally tree-like ansatz. Such an approximation, however, holds only to a limited extent, as real graphs are often characterized by high frequencies of short loops. We present here a theoretical framework able to overcome such a limitation for the case of site percolation. Our method is based on a message passing algorithm that discounts redundant paths along triangles in the...

Topics: Statistical Mechanics, Condensed Matter, Physics, Physics and Society

Source: http://arxiv.org/abs/1602.07140

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Jun 29, 2018
06/18

by
Filippo Radicchi; Claudio Castellano

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The stochastic addition of either vertices or connections in a network leads to the observation of the percolation transition, a structural change with the appearance of a connected component encompassing a finite fraction of the system. Percolation has always been regarded as a substrate-dependent but model-independent process, in the sense that the critical exponents of the transition are determined by the geometry of the system, but they are identical for the bond and site percolation...

Topics: Statistical Mechanics, Condensed Matter, Physics, Physics and Society

Source: http://arxiv.org/abs/1606.06933

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3.0

Jun 30, 2018
06/18

by
Filippo Radicchi; Claudio Castellano

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Many real-world systems are characterized by stochastic dynamical rules where a complex network of dependencies among individual elements probabilistically determines their state. Even with full knowledge of the network structure and of the stochastic rules of the dynamical process, the ability to predict system configurations is generally characterized by large uncertainty. Sampling a fraction of the nodes and deterministically observing their state may help to reduce the uncertainty about the...

Topics: Physics, Information Theory, Computing Research Repository, Physics and Society, Mathematics

Source: http://arxiv.org/abs/1703.03858

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Jun 29, 2018
06/18

by
Ginestra Bianconi; Filippo Radicchi

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We present an exact mathematical framework able to describe site-percolation transitions in real multiplex networks. Specifically, we consider the average percolation diagram valid over an infinite number of random configurations where nodes are present in the system with given probability. The approach relies on the locally treelike ansatz, so that it is expected to accurately reproduce the true percolation diagram of sparse multiplex networks with negligible number of short loops. The...

Topics: Statistical Mechanics, Condensed Matter, Physics, Physics and Society

Source: http://arxiv.org/abs/1610.08708

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Jun 29, 2018
06/18

by
Filippo Radicchi; Ginestra Bianconi

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In the analysis of the robustness of multiplex networks, it is commonly assumed that a node is functioning only if its interdependent nodes are simultaneously functioning. According to this model, a multiplex network becomes more and more fragile as the number of layers increases. In this respect, the addition of a new layer of interdependent nodes to a preexisting multiplex network will never improve its robustness. Whereas such a model seems appropriate to understand the effect of...

Topics: Statistical Mechanics, Condensed Matter, Physics, Physics and Society

Source: http://arxiv.org/abs/1610.05378

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0.0

Jun 29, 2018
06/18

by
V. I. Yukalov; D. Sornette

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We give a mathematical definition for the notion of inconclusive quantum measurements. In physics, such measurements occur at intermediate stages of a complex measurement procedure, with the final measurement result being operationally testable. Since the mathematical structure of Quantum Decision Theory has been developed in analogy with the theory of quantum measurements, the inconclusive quantum measurements correspond, in Quantum Decision Theory, to intermediate stages of decision making in...

Topics: Quantum Physics, Physics, Physics and Society

Source: http://arxiv.org/abs/1604.04739

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3.0

Jun 27, 2018
06/18

by
V. I. Yukalov; D. Sornette

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We show that the correct mathematical foundation of quantum decision theory, dealing with uncertain events, requires the use of positive operator-valued measure that is a generalization of the projection-valued measure. The latter is appropriate for operationally testable events, while the former is necessary for characterizing operationally uncertain events. In decision making, one has to distinguish composite non-entangled events from composite entangled events. The mathematical definition of...

Topics: Quantum Physics, Physics and Society, Physics

Source: http://arxiv.org/abs/1503.04750

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2.0

Jun 28, 2018
06/18

by
V. I. Yukalov; D. Sornette

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The influence of additional information on the decision making of agents, who are interacting members of a society, is analyzed within the mathematical framework based on the use of quantum probabilities. The introduction of social interactions, which influence the decisions of individual agents, leads to a generalization of the quantum decision theory developed earlier by the authors for separate individuals. The generalized approach is free of the standard paradoxes of classical decision...

Topics: Quantum Physics, Physics and Society, Physics

Source: http://arxiv.org/abs/1510.02686

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1.0

Jun 28, 2018
06/18

by
V. I. Yukalov; D. Sornette

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We consider the psychological effect of preference reversal and show that it finds a natural explanation in the frame of quantum decision theory. When people choose between lotteries with non-negative payoffs, they prefer a more certain lottery because of uncertainty aversion. But when people evaluate lottery prices, e.g. for selling to others the right to play them, they do this more rationally, being less subject to behavioral biases. This difference can be explained by the presence of the...

Topics: Quantum Physics, Physics and Society, Physics

Source: http://arxiv.org/abs/1510.02300

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0.0

Jun 30, 2018
06/18

by
Saeed Osat; Filippo Radicchi

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We extend the observability model to multiplex networks. We present mathematical frameworks, valid under the treelike ansatz, able to describe the emergence of the macroscopic cluster of mutually observable nodes in both synthetic and real-world multiplex networks. We show that the observability transition in synthetic multiplex networks is discontinuous. In real-world multiplex networks instead, edge overlap among layers is responsible for the disappearance of any sign of abruptness in the...

Topics: Physics, Computing Research Repository, Physics and Society, Social and Information Networks

Source: http://arxiv.org/abs/1701.04042

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Jun 29, 2018
06/18

by
Yang Yang; Filippo Radicchi

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We consider the observability model in networks with arbitrary topologies. We introduce a system of coupled nonlinear equations, valid under the locally tree-like ansatz, to describe the size of the largest observable cluster as a function of the fraction of directly observable nodes present in the network. We perform a systematic analysis on 95 real-world graphs and compare our theoretical predictions with numerical simulations of the observability model. Our method provides almost perfect...

Topics: Physics and Society, Statistical Mechanics, Condensed Matter, Physics, Computing Research...

Source: http://arxiv.org/abs/1607.07124

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0.0

Jun 29, 2018
06/18

by
Filippo Radicchi; Claudio Castellano

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Two very important problems regarding spreading phenomena in complex topologies are the optimal selection of node sets either to minimize or maximize the extent of outbreaks. Both problems are nontrivial when a small fraction of the nodes in the network can be used to achieve the desired goal. The minimization problem is equivalent to a structural optimization. The "superblockers", i.e., the nodes that should be removed from the network to minimize the size of outbreaks, are those...

Topics: Social and Information Networks, Computing Research Repository, Physics, Physics and Society

Source: http://arxiv.org/abs/1610.02908

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0.0

Jun 29, 2018
06/18

by
Filippo Radicchi; Claudio Castellano

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Among the consequences of the disordered interaction topology underlying many social, techno- logical and biological systems, a particularly important one is that some nodes, just because of their position in the network, may have a disproportionate effect on dynamical processes mediated by the complex interaction pattern. For example, the early adoption by an opinion leader in a social network may change the fate of a commercial product, or just a few super-spreaders may determine the virality...

Topics: Social and Information Networks, Computing Research Repository, Physics, Physics and Society

Source: http://arxiv.org/abs/1605.07041

2
2.0

Jun 30, 2018
06/18

by
V. I. Yukalov; D. Sornette

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We investigate how the choice of decision makers can be varied under the presence of risk and uncertainty. Our analysis is based on the approach we have previously applied to individual decision makers, which we now generalize to the case of decision makers that are members of a society. The approach employs the mathematical techniques that are common in quantum theory, justifying our naming as Quantum Decision Theory. However, we do not assume that decision makers are quantum objects. The...

Topics: Physics, Quantum Physics, Quantitative Finance, Physics and Society, General Finance

Source: http://arxiv.org/abs/1409.0636

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1.0

Jun 30, 2018
06/18

by
V. I. Yukalov; D. Sornette

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The idea is advanced that self-organization in complex systems can be treated as decision making (as it is performed by humans) and, vice versa, decision making is nothing but a kind of self-organization in the decision maker nervous systems. A mathematical formulation is suggested based on the definition of probabilities of system states, whose particular cases characterize the probabilities of structures, patterns, scenarios, or prospects. In this general framework, it is shown that the...

Topics: Physics, Nonlinear Sciences, Physics and Society, Adaptation and Self-Organizing Systems

Source: http://arxiv.org/abs/1408.1529

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2.0

Jun 29, 2018
06/18

by
V. I. Yukalov; D. Sornette

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A rigorous general definition of quantum probability is given, which is valid for elementary events and for composite events, for operationally testable measurements as well as for inconclusive measurements, and also for non-commuting observables in addition to commutative observables. Our proposed definition of quantum probability makes it possible to describe quantum measurements and quantum decision making on the same common mathematical footing. Conditions are formulated for the case when...

Topics: Quantum Physics, Physics, Mathematics, Information Theory, Computing Research Repository, Physics...

Source: http://arxiv.org/abs/1601.02480

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6.0

Jun 30, 2018
06/18

by
V. I. Yukalov; D. Sornette

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We demonstrate that behavioral probabilities of human decision makers share many common features with quantum probabilities. This does not imply that humans are some quantum objects, but just shows that the mathematics of quantum theory is applicable to the description of human decision making. The applicability of quantum rules for describing decision making is connected with the nontrivial process of making decisions in the case of composite prospects under uncertainty. Such a process...

Topics: Physics, Quantitative Biology, Neurons and Cognition, Quantum Physics, Physics and Society

Source: http://arxiv.org/abs/1703.05691

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0.0

Jun 29, 2018
06/18

by
Filippo Radicchi; Alexander Weissman; Johan Bollen

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Citations are commonly held to represent scientific impact. To date, however, there is no empirical evidence in support of this postulate that is central to research assessment exercises and Science of Science studies. Here, we report on the first empirical verification of the degree to which citation numbers represent scientific impact as it is actually perceived by experts in their respective field. We run a large-scale survey of about 2000 corresponding authors who performed a pairwise...

Topics: Physics, Digital Libraries, Computing Research Repository, Physics and Society

Source: http://arxiv.org/abs/1612.03962

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4.0

Jun 28, 2018
06/18

by
V. I. Yukalov; E. P. Yukalova; D. Sornette

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We propose a reduced form set of two coupled continuous time equations linking the price of a representative asset and the price of a bond, the later quantifying the cost of borrowing. The feedbacks between asset prices and bonds are mediated by the dependence of their "fundamental values" on past asset prices and bond themselves. The obtained nonlinear self-referencing price dynamics can induce, in a completely objective deterministic way, the appearance of periodically exploding...

Topics: General Finance, Physics and Society, Quantitative Finance, Physics

Source: http://arxiv.org/abs/1507.05311

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0.0

Jun 30, 2018
06/18

by
V. I. Yukalov; E. P. Yukalova; D. Sornette

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We consider a class of evolution equations describing population dynamics in the presence of a carrying capacity depending on the population with delay. In an earlier work, we presented an exhaustive classification of the logistic equation where the carrying capacity is linearly dependent on the population with a time delay, which we refer to as the "linear delayed carrying capacity" model. Here, we generalize it to the case of a nonlinear delayed carrying capacity. The nonlinear...

Topics: Populations and Evolution, Physics, Quantitative Biology, Physics and Society

Source: http://arxiv.org/abs/1403.2051

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Jun 30, 2018
06/18

by
V. I. Yukalov; E. P. Yukalova; D. Sornette

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We present a novel system of equations to describe the evolution of self-organized structured societies (biological or human) composed of several trait groups. The suggested approach is based on the combination of ideas employed in the theory of biological populations, system theory, and utility theory. The evolution equations are defined as utility rate equations, whose parameters are characterized by the utility of each group with respect to the society as a whole and by the mutual utilities...

Topics: Physics, Populations and Evolution, Physics and Society, Quantitative Biology

Source: http://arxiv.org/abs/1401.1321

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Jun 30, 2018
06/18

by
Jasleen Kaur; Emilio Ferrara; Filippo Menczer; Alessandro Flammini; Filippo Radicchi

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Citation metrics are becoming pervasive in the quantitative evaluation of scholars, journals and institutions. More then ever before, hiring, promotion, and funding decisions rely on a variety of impact metrics that cannot disentangle quality from quantity of scientific output, and are biased by factors such as discipline and academic age. Biases affecting the evaluation of single papers are compounded when one aggregates citation-based metrics across an entire publication record. It is not...

Topics: Digital Libraries, Physics, Computing Research Repository, Physics and Society

Source: http://arxiv.org/abs/1411.7357

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Jun 29, 2018
06/18

by
M. Favre; A. Wittwer; H. R. Heinimann; V. I. Yukalov; D. Sornette

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Quantum decision theory (QDT) is a recently developed theory of decision making based on the mathematics of Hilbert spaces, a framework known in physics for its application to quantum mechanics. This framework formalizes the concept of uncertainty and other effects that are particularly manifest in cognitive processes, which makes it well suited for the study of decision making. QDT describes a decision maker's choice as a stochastic event occurring with a probability that is the sum of an...

Topics: Physics, Physics and Society

Source: http://arxiv.org/abs/1602.04058

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Jun 27, 2018
06/18

by
Qing Ke; Emilio Ferrara; Filippo Radicchi; Alessandro Flammini

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A Sleeping Beauty (SB) in science refers to a paper whose importance is not recognized for several years after publication. Its citation history exhibits a long hibernation period followed by a sudden spike of popularity. Previous studies suggest a relative scarcity of SBs. The reliability of this conclusion is, however, heavily dependent on identification methods based on arbitrary threshold parameters for sleeping time and number of citations, applied to small or monodisciplinary...

Topics: Social and Information Networks, Physics and Society, Digital Libraries, Computing Research...

Source: http://arxiv.org/abs/1505.06454