182,278 research outputs found

    Relevant elments, Magnetization and Dynamical Properties in Kauffman Networks: a Numerical Study

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    This is the first of two papers about the structure of Kauffman networks. In this paper we define the relevant elements of random networks of automata, following previous work by Flyvbjerg and Flyvbjerg and Kjaer, and we study numerically their probability distribution in the chaotic phase and on the critical line of the model. A simple approximate argument predicts that their number scales as sqrt(N) on the critical line, while it is linear with N in the chaotic phase and independent of system size in the frozen phase. This argument is confirmed by numerical results. The study of the relevant elements gives useful information about the properties of the attractors in critical networks, where the pictures coming from either approximate computation methods or from simulations are not very clear.Comment: 22 pages, Latex, 8 figures, submitted to Physica

    Hierarchic trees with branching number close to one: noiseless KPZ equation with additional linear term for imitation of 2-d and 3-d phase transitions.

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    An imitation of 2d field theory is formulated by means of a model on the hierarhic tree (with branching number close to one) with the same potential and the free correlators identical to 2d correlators ones. Such a model carries on some features of the original model for certain scale invariant theories. For the case of 2d conformal models it is possible to derive exact results. The renormalization group equation for the free energy is noiseless KPZ equation with additional linear term.Comment: latex, 5 page

    Multiple Shocks in a Driven Diffusive System with Two Species of Particles

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    A one-dimensional driven diffusive system with two types of particles and nearest neighbors interactions has been considered on a finite lattice with open boundaries. The particles can enter and leave the system from both ends of the lattice and there is also a probability for converting the particle type at the boundaries. We will show that on a special manifold in the parameters space multiple shocks evolve in the system for both species of particles which perform continuous time random walks on the lattice.Comment: 11 pages, 1 figure, accepted for publication in Physica

    Kinetics of Coalescence, Annihilation, and the q-State Potts Model in One Dimension

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    The kinetics of the q-state Potts model in the zero temperature limit in one dimension is analyzed exactly through a generalization of the method of empty intervals, previously used for the analysis of diffusion-limited coalescence, A+A->A. In this new approach, the q-state Potts model, coalescence, and annihilation (A+A->0) all satisfy the same diffusion equation, and differ only in the imposed initial condition.Comment: 4 pages, RevTeX, submitted to Phys. Lett.

    "As Nobody I was Sovereign": reading Derrida reading Blanchot

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    In Session 7 (26 February 2003) of The Beast and the Sovereign, Volume II, Jacques Derrida engages again with Maurice Blanchot, two days after the latter’s cremation. This intervention also appears as a post-face to Derrida’s 2003 edition of Parages, his collection of essays devoted to the work of Blanchot. In this article, I examine Derrida’s affinity to the work of Blanchot, as the one whose work ‘stood watch over and around what matters to me, for a long time behind me and forever still before me’ [The Beast and the Sovereign, Volume II, p. 176]. In doing so I look at the manner in which Derrida engaged with Blanchot in his work and how in examining this engagement another reading of sovereignty emerges, one which is not tethered to liberal models of sovereign will but one which eludes biopolitical ordering and may be seen as a form of disappearance. Through a reading of Derrida’s readings of Blanchot’s The Madness of the Day I emphasize the link of this alternative sovereignty to both writing and literature in order to demonstrate how a more radical thinking of sovereignty can be discovered in Derrida’s thought

    Persistence exponent in a superantiferromagnetic quenching

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    We measure the persistence exponent in a phase separating two-dimensional spin system with non-conserved dynamics quenched in a region with four coexisting stripe phases. The system is an Ising model with nearest neighbor, next-to-the-nearest neighbor and plaquette interactions. Due the particular nature of the ground states, the order parameter is defined in terms of blocks of spins. Our estimate of the persistence exponent, θ=0.42\theta=0.42, differs from those of the two-dimensional Ising and four state Potts models. Our procedure allows the study of persistence properties also at finite temperature TT: our results are compatible with the hypothesis that θ\theta does not depend on TT below the critical point.Comment: LaTeX file with postscript figure

    Phase Transition in NK-Kauffman Networks and its Correction for Boolean Irreducibility

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    In a series of articles published in 1986 Derrida, and his colleagues studied two mean field treatments (the quenched and the annealed) for \textit{NK}-Kauffman Networks. Their main results lead to a phase transition curve Kc2pc(1pc)=1 K_c \, 2 \, p_c \left( 1 - p_c \right) = 1 (0<pc<1 0 < p_c < 1 ) for the critical average connectivity Kc K_c in terms of the bias pc p_c of extracting a "11" for the output of the automata. Values of K K bigger than Kc K_c correspond to the so-called chaotic phase; while K<Kc K < K_c , to an ordered phase. In~[F. Zertuche, {\it On the robustness of NK-Kauffman networks against changes in their connections and Boolean functions}. J.~Math.~Phys. {\bf 50} (2009) 043513], a new classification for the Boolean functions, called {\it Boolean irreducibility} permitted the study of new phenomena of \textit{NK}-Kauffman Networks. In the present work we study, once again the mean field treatment for \textit{NK}-Kauffman Networks, correcting it for {\it Boolean irreducibility}. A shifted phase transition curve is found. In particular, for pc=1/2 p_c = 1 / 2 the predicted value Kc=2 K_c = 2 by Derrida {\it et al.} changes to Kc=2.62140224613 K_c = 2.62140224613 \dots We support our results with numerical simulations.Comment: 23 pages, 7 Figures on request. Published in Physica D: Nonlinear Phenomena: Vol.275 (2014) 35-4

    Derrida reappraised : deconstruction, critique and emancipation in management studies

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    Derrida has been significantly misread by many management scholars. The paper argues that his work is not ‘postmodernist’; further, that Habermas’ (1987) influential critique of Derrida’s views on truth and politics have led to widespread but misleading views of his critical credentials. Although Habermas is not entirely misguided, a defence of Derrida is provided that sets out the potential for his work to inform management scholars who wish to provide emancipatory critique

    Derrida's Territorial Knowledge of Justice

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    Peter Fitzpatrick’s writings prove once and for all that it is possible for a law professor to write in beautiful English. His work also proves once and for all that the dominating tradition of Anglo-American legal philosophy and of law teaching has been barking up the wrong tree: namely, that the philosopher and professional law teachers can understand justice as nested in empty forms, better known as rules, doctrines, principles, policies, and other standards. The more rigorous our analysis or decomposition of the forms, we have believed, the more closely do we access the identity of laws. Justice has been assumed to be a matter of intellectually accessing such analysed forms. Fitzpatrick’s articles and books embody an implicit critique of the analytic view of law and of justice. My entry point into this critique is his preoccupation with Jacques Derrida’s theory of laws as universals and with Derrida’s theory of justice as an inaccessible immediacy or presence in context-specific or concrete experienced events. Each event is experienced in an official’s decision. Such a decision represents what Derrida, Fitzpatrick, and Hegel call ‘individuality’. Derrida’s theory of law presents a conundrum. Derrida misses the possibility that law may exist by virtue of its content rather than its form. Derrida misses this possibility because, heavily influenced by Kant (in Derrida’s theory of law), Derrida associates law with universals. This is so because Kant (and Derrida) are preoccupied with the identity of what counts as a law (lois) rather than with a law’s legitimacy. A universal cannot exist unless it is legitimate, and it is legitimate, I claim, by virtue of its content. In his association of law with universals, Derrida presupposes that legal knowledge exists with reference to a territorial-like boundary. The forms are represented or signified by signs (signifiers) within a boundary of the ultimate form (the state, the nation, or humanity). This ultimate form as a universal, like the discrete rules or forms, lacks socially contingent content. A boundary separates knowable universals from the unknowable world on the exteriority of the boundary. The unknowable world is constituted by concrete events experienced in context-specific circumstances. In his legal theory Derrida hones in upon the decision as the experienced event. In a decision, one is present or immediate with the event. Derrida considers such immediacy as justice. The immediacy, however, can only be represented as a sign (sometimes called a signifier). The sign, in turn, represents an empty signified or form, according to Derrida. Because the immediacy remains a representation rather than a presentation of the experienced event, laws as universals cannot be just. The rupture between the inaccessible immediacy of a decision on the one hand and the represented empty forms on the other is critical to Derrida’s theory of law. I claim that this rupture permeates Derrida’s writings about law because Derrida possesses a territorial-like sense of legal knowledge. I shall argue to this effect as follows. In the first section I shall explain the importance of Fitzpatrick’s exposure of the vacuity of the foundation of the system or structure of universals. In the second section I shall flesh out two elements of Derrida’s legal theory: law as form and the ipseity or concrete event that the form excludes from law. This takes me to the third section, where I shall elaborate how Derrida’s legal theory presupposes knowledge as territorial. I shall argue in the final section that this very sense of territorial knowledge prevents justice from accessing law and law from accessing justice. I conclude with the hint of a very different sense of law, one that draws from experiential knowledge in contradistinction to territorial knowledge
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