Communication and language in Niklas Luhmann's systems theory

This article investigates the function and reality of language in Niklas Luhmann's systems theory. How can one interpret the systems-theoretical assumption that language is based on communication? Luhmann describes language as a dynamic media/form relationship, which is able to couple the social and psychological system. This structural coupling, which constructs consciousness and language as two autonomous systems, raises problems if one defines language from a cognitive point of view. This article discusses these problems and aims to develop assumptions and questions within the systems-theoretical approach.O presente artigo investiga a função e realidade da linguagem na teoria dos sistemas de Niklas Luhmann. Como se pode interpretar a suposição sistêmico-teórica de que a linguagem é baseada na comunicação? Luhmann descreve a linguagem como uma relação dinâmica entre meio e forma, a qual é capaz de ligar o sistema social e psicológico. Essa conexão estrutural, que constroi a consciência e a linguagem como dois sistemas autônomos, gera problemas quando se define a linguagem do ponto de vista cognitivo. Este artigo discute tais problemas e pretende desenvolver suposições e questões a partir da própria abordagem sistêmico-teórica

Review of AdS/CFT Integrability: An Overview

This is the introductory chapter of a review collection on integrability in the context of the AdS/CFT correspondence. In the collection we present an overview of the achievements and the status of this subject as of the year 2010.Comment: 31 pages, v2: reference added, references to other chapters updated, v3: footnote 1 on location of references added, v4: minor changes, references added, accepted for publication in Lett. Math. Phys, v5: minor corrections, links to chapters updated, attached IntAdS.pdf with all chapters in one file, see http://arxiv.org/src/1012.3982/anc/IntAdS.pdf or http://www.phys.ethz.ch/~nbeisert/IntAdS.pd

Management as a Symbolizing Construction?

In this article, we outline the concept of management as a symbolizing construction. According to Niklas LUHMANN, organizations process by referring to decisions. But decisions are not simply "given" and in principle invisible. This is the reason why organizations institute formalities like protocols, signatures or other insignia of the official that symbolize the decision—without actually being a decision. These symbols allow for making decisions "process-able." And just like a protocol or a signature, management symbolizes decisions as well. Management provides an organizational practice with symbols of decision making without being the "unity" of the decisions, as decisions perpetually have to be reconstructed, redefined and rearranged in the communication of all organizational units. Therefore management symbolizes on the one hand more than it can achieve. On the other hand the importance of management as a symbolizing construction lies in allowing the reconstruction, redefining and rearrangement of decisions by making them visible and recognizable. Heroic managers, meetings, management tools and procedures are solutions to the paradox of decision making. By symbolizing decidedness they create credibilities that conceal the self-referential construction of organizational communication and the paradox of its decision praxis

On Yangian Symmetry in Planar N=4 SYM

Planar N=4 supersymmetric Yang-Mills theory appears to be perturbatively integrable. This work reviews integrability in terms of a Yangian algebra and compares the application to the problems of anomalous dimensions and scattering amplitudes.Comment: 24 pages, To Lev Lipatov on the occasion of his 70th birthday, v2: references and typos corrected, v3: no changes, references updated, published in "Subtleties in Quantum Field Theory", pp. 175, ed: D. Diakonov and "Gribov-80 Memorial Volume: Quantum Chromodynamics and Beyond", pp. 413, ed: Yu. Dokshitzer, P. L\'evai, J. Ny\'ir

Beyond the ‘other’ as constitutive outside: : The politics of immunity in Roberto Esposito and Niklas Luhmann

This article re-conceptualises the ‘constitutive outside’ through Roberto Esposito’s theory of immunity to detach it from Laclau and Mouffe’s political antagonism. It identifies Esposito’s thought as an innovative epistemological perspective to dissolve post-ontological political theories of community from the intertwinement with a foundational self/other dialectic. Esposito shows how a community can sustain its relations through introversive immunisation against a primarily undefined outside. But it is argued that his theory of immunity slips back to a vitalist depth ontology which ultimately de-politicises the construction of the communal outside. This article draws on Niklas Luhmann’s immunity theory to resituate immunisation in the political production of social connectivity. Following Luhmann, politics relies on immunisation through contradictions to reproduce its functional role as a decision-making institution, but is at the same time constantly exposed to potential rupture through the political openness immunity introduces. Through Esposito and Luhmann, this article identifies the relationship between a social inside and its outside as open-ended and secondary to an introversive process of socio-political self-differentiation. It can involve, but does epistemologically necessitate, the construction of an external otherPeer reviewedFinal Accepted Versio

Economics of gift - positivity of justice : the mutual paranoia of Jacques Derrida and Niklas Luhmann

S.a. Deutsche Fassung: Ökonomie der Gabe - Positivität der Gerechtigkeit: Gegenseitige Heimsuchungen von System und différance. In: Albrecht Koschorke und Cornelia Vismann (Hg.) System - Macht - Kultur: Probleme der Systemtheorie. Akademie, Berlin 1999, 199-212. Auch auf unserem Server vorhanden. * Italienische Fassung: Economia del dono, positività della giustizia: la reciproca paranoia di Jacques Derrida e Niklas Luhmann. Sociologia e politiche sociali 6, 2003, 113-130. Portugiesische Fassung: Economia da dádiva ? posividade da rustica; ?assombracao?? mutua entre sistema e différance. In: Gunther Teubner, Direito, Sistema, Policontexturalidade, Editora Unimep, Piracicaba Sao Paolo, Brasil 2005, 55-78

Cues for shelter use in a phytophagous insect

Many insects spend a large proportion of their life inactive, often hiding in shelters. The presence of shelters may, therefore, influence where insects feed. This study examines stimuli affecting the use of shelters by adults of the pine weevil, Hylobius abietis (L.) (Coleoptera, Curculionidae). This species is an economically important forest pest in Europe since the adults feed on the stem bark of newly planted conifer seedlings. When there are hiding or burrowing places present in close proximity to a seedling, pine weevils may hide there and repeatedly return to feed on the same seedling. Experiments were conducted in a laboratory arena with above-ground or below-ground shelters and in the presence or absence of wind. Pine weevils were highly attracted to shelters both above and below ground. Weevils in shelters were often observed assuming a characteristic "resting" posture. Experiments with opaque and transparent shelters showed that visual stimuli are used for orientation towards shelters and also increase the probability of an individual remaining in a shelter. The presence of wind increased the weevils' propensity to use shelters both above and below ground. The present study indicates that shelters have a major influence on the behavior of the pine weevil and possible implications of the results are discussed

Higher loops, integrability and the near BMN limit

In this note we consider higher-loop contributions to the planar dilatation operator of N=4 SYM in the su(2) subsector of two complex scalar fields. We investigate the constraints on the form of this object due to interactions of two excitations in the BMN limit. We then consider two scenarios to uniquely fix some higher-loop contributions: (i) Higher-loop integrability fixes the dilatation generator up to at least four-loops. Among other results, this allows to conjecture an all-loop expression for the energy in the near BMN limit. (ii) The near plane-wave limit of string theory and the BMN correspondence fix the dilatation generator up to three-loops. We comment on the difference between both scenarios.Comment: 6 page

One-Loop Superconformal and Yangian Symmetries of Scattering Amplitudes in N=4 Super Yang-Mills

Recently it has been argued that tree-level scattering amplitudes in N=4 Yang-Mills theory are uniquely determined by a careful study of their superconformal and Yangian symmetries. However, at one-loop order these symmetries are known to become anomalous due to infrared divergences. We compute these one-loop anomalies for amplitudes defined through dimensional regularisation by studying the tree-level symmetry transformations of the unitarity branch cuts, keeping track of the crucial collinear terms arising from the holomorphic anomaly. We extract the superconformal anomalies and show that they may be cancelled through a universal one-loop deformation of the tree-level symmetry generators which involves only tree-level data. Specialising to the planar theory we also obtain the analogous deformation for the level-one Yangian generator of momentum. Explicit checks of our one-loop deformation are performed for MHV and the 6-point NMHV amplitudes.Comment: 64 pages, v2: typos and minor corrections in (6.14) and (6.17), to appear in JHE