Publications
179 results found
Pereira T, Eroglu, Bagci, et al., 2013, Connectivity-Driven Coherence in Complex Networks, Physical Review Letters, Vol: 110
We study the emergence of coherence in complex networks of mutually coupled nonidentical elements. We uncover the precise dependence of the dynamical coherence on the network connectivity, the isolated dynamics of the elements, and the coupling function. These findings predict that in random graphs the enhancement of coherence is proportional to the mean degree. In locally connected networks, coherence is no longer controlled by the mean degree but rather by how the mean degree scales with the network size. In these networks, even when the coherence is absent, adding a fraction s of random connections leads to an enhancement of coherence proportional to s. Our results provide a way to control the emergent properties by the manipulation of the dynamics of the elements and the network connectivity.
Petri G, Expert P, Jensen HJ, et al., 2013, Entangled communities and spatial synchronization lead to criticality in urban traffic, SCIENTIFIC REPORTS, Vol: 3, ISSN: 2045-2322
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- Citations: 22
Robalino JD, Jensen HJ, 2013, Entangled economy: An ecosystems approach to modeling systemic level dynamics, PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS, Vol: 392, Pages: 773-784, ISSN: 0378-4371
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- Citations: 6
Sibani P, Jensen HJ, 2013, Stochastic Dynamics of Complex Systems From Glasses to Evolution, ISBN: 9781848169937
The main focus of this book is on the stochastic processes which cause ageing, and the surprising fact that the ageing dynamics of systems which are very different at the microscopic level can be treated in similar ways.
Gaucherel C, Jensen HJ, 2012, Origins of evolution: Non-acquired characters dominates over acquired characters in changing environment, JOURNAL OF THEORETICAL BIOLOGY, Vol: 304, Pages: 111-120, ISSN: 0022-5193
Alarcon T, Jensen HJ, 2012, Invasion in multi-type populations: the role of phenotypic robustness and fluctuations, MATHEMATICAL MEDICINE AND BIOLOGY-A JOURNAL OF THE IMA, Vol: 29, Pages: 3-20, ISSN: 1477-8599
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- Citations: 1
Giometto A, Jensen HJ, 2012, Connecting the microdynamics to the emergent macrovariables: Self-organized criticality and absorbing phase transitions in the deterministic lattice gas, PHYSICAL REVIEW E, Vol: 85, ISSN: 1539-3755
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- Citations: 6
Giometto A, Jensen HJ, 2012, Connecting the microdynamics to the emergent macrovariables: Self-organized criticality and absorbing phase transitions in the deterministic lattice gas., Phys Rev E, Vol: 85, ISSN: 1539-3755
We reinvestigate the Deterministic Lattice Gas introduced as a paradigmatic model of the 1/f spectra [Phys. Rev. Lett. 64, 3103 (1990)] arising according to the self-organized criticality scenario. We demonstrate that the density fluctuations exhibit an unexpected dependence on systems size and relate the finding to effective Langevin equations. The low-density behavior is controlled by the critical properties of the gas at the absorbing state phase transition. We also show that the deterministic lattice gas is in the Manna universality class of absorbing state phase transitions. This is in contrast to expectations in the literature that suggested that the entirely deterministic nature of the dynamics would put the model in a different universality class. To our knowledge this is the first fully deterministic member of the Manna universality class.
Giometto A, Jensen HJ, 2012, Connecting the microdynamics to the emergent macrovariables: self-organized criticality and absorbing phase transitions in the Deterministic Lattice Gas., Phys Rev E Stat Nonlin Soft Matter Phys, Vol: 85
We reinvestigate the Deterministic Lattice Gas introduced as a paradigmatic model of the 1/f spectra [Phys. Rev. Lett. 64, 3103 (1990)] arising according to the self-organized criticality scenario. We demonstrate that the density fluctuations exhibit an unexpected dependence on systems size and relate the finding to effective Langevin equations. The low-density behavior is controlled by the critical properties of the gas at the absorbing state phase transition. We also show that the deterministic lattice gas is in the Manna universality class of absorbing state phase transitions. This is in contrast to expectations in the literature that suggested that the entirely deterministic nature of the dynamics would put the model in a different universality class. To our knowledge this is the first fully deterministic member of the Manna universality class.
Tirnakli U, Jensen HJ, Tsallis C, 2011, Restricted random walk model as a new testing ground for the applicability of q-statistics, EPL, Vol: 96, ISSN: 0295-5075
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- Citations: 8
Richardson TO, Christensen K, Franks NR, et al., 2011, Ants in a labyrinth: A statistical mechanics approach to the division of labour, PLOS One, Vol: 6, ISSN: 1932-6203
Division of labour (DoL) is a fundamental organisational principle in human societies, within virtual and robotic swarms and at all levels of biological organisation. DoL reaches a pinnacle in the insect societies where the most widely used model is based on variation in response thresholds among individuals, and the assumption that individuals and stimuli are well-mixed. Here, we present a spatially explicit model of DoL. Our model is inspired by Pierre de Gennes' 'Ant in a Labyrinth' which laid the foundations of an entire new field in statistical mechanics. We demonstrate the emergence, even in a simplified one-dimensional model, of a spatial patterning of individuals and a right-skewed activity distribution, both of which are characteristics of division of labour in animal societies. We then show using a two-dimensional model that the work done by an individual within an activity bout is a sigmoidal function of its response threshold. Furthermore, there is an inverse relationship between the overall stimulus level and the skewness of the activity distribution. Therefore, the difference in the amount of work done by two individuals with different thresholds increases as the overall stimulus level decreases. Indeed, spatial fluctuations of task stimuli are minimised at these low stimulus levels. Hence, the more unequally labour is divided amongst individuals, the greater the ability of the colony to maintain homeostasis. Finally, we show that the non-random spatial distribution of individuals within biological and social systems could be caused by indirect (stigmergic) interactions, rather than direct agent-to-agent interactions. Our model links the principle of DoL with principles in the statistical mechanics and provides testable hypotheses for future experiments.
Expert P, Lambiotte R, Chialvo DR, et al., 2011, Self-similar correlation function in brain resting-state functional magnetic resonance imaging, JOURNAL OF THE ROYAL SOCIETY INTERFACE, Vol: 8, Pages: 472-479, ISSN: 1742-5689
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- Citations: 106
Richardson TO, Christensen K, Franks NR, et al., 2011, Group dynamics and record signals in the ant <i>Temnothorax albipennis</i>, JOURNAL OF THE ROYAL SOCIETY INTERFACE, Vol: 8, Pages: 518-528, ISSN: 1742-5689
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- Citations: 3
Richardson TO, Robinson EJH, Christensen K, et al., 2011, Comment on P. Nouvellet, JP Bacon, D. Waxman, "Testing the level of ant activity associated with quorum sensing: An empirical approach leading to the establishment and test of a null-model", JOURNAL OF THEORETICAL BIOLOGY, Vol: 269, Pages: 356-358, ISSN: 0022-5193
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- Citations: 3
Alarcon T, Jensen HJ, 2011, Quiescence: a mechanism for escaping the effects of drug on cell populations, JOURNAL OF THE ROYAL SOCIETY INTERFACE, Vol: 8, Pages: 99-106, ISSN: 1742-5689
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- Citations: 19
Peel A, Jensen HJ, 2011, DELAY BEFORE SYNCHRONIZATION AND ITS ROLE IN LATENCY OF SENSORY AWARENESS, INTERNATIONAL JOURNAL OF MODERN PHYSICS C, Vol: 22, Pages: 85-94, ISSN: 0129-1831
Jones D, Jensen HJ, Sibani P, 2010, Tempo and mode of evolution in the tangled nature model, PHYSICAL REVIEW E, Vol: 82, ISSN: 1539-3755
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- Citations: 5
Benkoe G, Jensen HJ, 2010, Logarithmically slow onset of synchronization, JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL, Vol: 43, ISSN: 1751-8113
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- Citations: 1
Richardson TO, Robinson EJH, Christensen K, et al., 2010, Record dynamics in ants, PLOS One, Vol: 5, ISSN: 1932-6203
The success of social animals (including ourselves) can be attributed to efficiencies that arise from a division of labour. Many animal societies have a communal nest which certain individuals must leave to perform external tasks, for example foraging or patrolling. Staying at home to care for young or leaving to find food is one of the most fundamental divisions of labour. It is also often a choice between safety and danger. Here we explore the regulation of departures from ant nests. We consider the extreme situation in which no one returns and show experimentally that exiting decisions seem to be governed by fluctuating record signals and ant-ant interactions. A record signal is a new ‘high water mark’ in the history of a system. An ant exiting the nest only when the record signal reaches a level it has never perceived before could be a very effective mechanism to postpone, until the last possible moment, a potentially fatal decision. We also show that record dynamics may be involved in first exits by individually tagged ants even when their nest mates are allowed to re-enter the nest. So record dynamics may play a role in allocating individuals to tasks, both in emergencies and in everyday life. The dynamics of several complex but purely physical systems are also based on record signals but this is the first time they have been experimentally shown in a biological system.
Jones D, Jensen HJ, Sibani P, 2010, Mutual information in the Tangled Nature model, ECOLOGICAL MODELLING, Vol: 221, Pages: 400-404, ISSN: 0304-3800
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- Citations: 1
Jensen HJ, Arcaute E, 2010, Complexity, collective effects, and modeling of ecosystems: formation, function, and stability, ECOLOGICAL COMPLEXITY AND SUSTAINABILITY, Vol: 1195, Pages: E19-E26, ISSN: 0077-8923
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- Citations: 6
Arcaute E, Christensen K, Sendova-Franks A, et al., 2009, Division of labour in ant colonies in terms of attractive fields, Eco Summit 2007, Publisher: ELSEVIER, Pages: 396-402, ISSN: 1476-945X
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- Citations: 10
Petri G, Jensen HJ, Polak JW, 2009, Global and local information in traffic congestion, EPL, Vol: 88, ISSN: 0295-5075
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- Citations: 8
Windus AL, Jensen HJ, 2009, Change in order of phase transitions on fractal lattices, PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS, Vol: 388, Pages: 3107-3112, ISSN: 0378-4371
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- Citations: 10
Lawson DJ, Jensen HJ, 2009, The role of weak selection and high mutation rates in nearly neutral evolution, JOURNAL OF THEORETICAL BIOLOGY, Vol: 257, Pages: 696-703, ISSN: 0022-5193
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- Citations: 1
Windus A, Jensen HJ, 2009, Accuracy of the cluster-approximation method in a nonequilibrium model, JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, ISSN: 1742-5468
Windus AL, Jensen HJ, 2009, CLUSTER GEOMETRY AND EXTINCTION, INTERNATIONAL JOURNAL OF MODERN PHYSICS C, Vol: 20, Pages: 97-107, ISSN: 0129-1831
Windus A, Jensen HJ, 2008, Cluster geometry and survival probability in systems driven by reaction-diffusion dynamics, NEW JOURNAL OF PHYSICS, Vol: 10, ISSN: 1367-2630
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- Citations: 5
Jensen HJ, 2008, Emergence of network structure in models of collective evolution and evolutionary dynamics, PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 464, Pages: 2207-2217, ISSN: 1364-5021
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- Citations: 6
Hatzopoulos V, Jensen HJ, 2008, Prisoner's dilemma on a stochastic nongrowth network evolution model, PHYSICAL REVIEW E, Vol: 78, ISSN: 2470-0045
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- Citations: 11
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