On the influence of the cosmological constant on gravitational lensing in small systems

The cosmological constant Lambda affects gravitational lensing phenomena. The contribution of Lambda to the observable angular positions of multiple images and to their amplification and time delay is here computed through a study in the weak deflection limit of the equations of motion in the Schwarzschild-de Sitter metric. Due to Lambda the unresolved images are slightly demagnified, the radius of the Einstein ring decreases and the time delay increases. The effect is however negligible for near lenses. In the case of null cosmological constant, we provide some updated results on lensing by a Schwarzschild black hole.Comment: 8 pages, 1 figure; v2: extended discussion on the lens equation, references added, results unchanged, in press on PR

Margarita de Sossa, Sixteenth-Century Puebla de los Ángeles, New Spain (Mexico)

Margarita de Sossa’s freedom journey was defiant and entrepreneurial. In her early twenties, still enslaved in Portugal, she took possession of her body; after refusing to endure her owner’s sexual demands, he sold her, and she was transported to Mexico. There, she purchased her freedom with money earned as a healer and then conducted an enviable business as an innkeeper. Sossa’s biography provides striking insights into how she conceptualized freedom in terms that included – but was not limited to – legal manumission. Her transatlantic biography offers a rare insight into the life of a free black woman (and former slave) in late sixteenth-century Puebla, who sought to establish various degrees of freedom for herself. Whether she was refusing to acquiesce to an abusive owner, embracing entrepreneurship, marrying, purchasing her own slave property, or later using the courts to petition for divorce. Sossa continued to advocate on her own behalf. Her biography shows that obtaining legal manumission was not always equivalent to independence and autonomy, particularly if married to an abusive husband, or if financial successes inspired the envy of neighbors

Social sciences as learning systems

Die Studie analysiert den Funktionswandel im Selbstverstaendnis der Sozialwissenschaften vor dem Hintergrund einer fortschreitenden Proliferation und Spezialisierung der Wissenschaften. Eroertert wird dabei die Frage, ob heute die Forderung nach einer Integration und Vereinheitlichung des fragmentierten Wissens noch machbar ist oder wir sie als eine 'romantische Illusion' verabschieden sollten. Der Autor sucht unterhalb der Schwelle einer integrativen 'grand theory' nach den Moeglichkeiten der Vernetzung des Wissens durch interdisziplinaere Forschung und der Schaffung spezifischer institutioneller Arrangements in den Sozialwissenschaften, die interdisziplinaere Lernprozesse beguenstigen. Von diesem Ansatz her erscheint das System der Sozialwissenschaften insgesamt als ein lernendes, umweltoffenes und adaptives System, das durch selbstorganisierende Mechanismen seine Identitaet und damit auch Anschlussmoeglichkeiten durch Wissenstransfer wahrt. (ICA)German title: Die Sozialwissenschaften als lernendes SystemAvailable from UuStB Koeln(38)-20030106782 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Postindustrialism and postmaterialism? A critical view of the 'New Economy', the 'Information Age', the 'High Tech Society', and all that

'The theory of postindustrial society and postmaterialist culture can explain neither the structural uniformities of modern society captured by convergence theory nor the national differences captured by theories of democratic corporatism and the mass society. Its depiction of structural changes is superficial: the service sector is too heterogeneous to describe occupational and industrial trends; the idea of technocratic dominance is overblown and misses big national differences in the location and role of experts and intellectuals. As for postindustrial values, they apply to a small population, a minority even of college students. That these attitudes fluctuate so much with shifting economic conditions and political agendas casts doubt on the idea of a basic shift toward 'postmaterial values'. The literature documenting such shifts is plagued with problems of survey validity. It goes up against a heavy weight of evidence showing that older issues of security, equality, civic order and crime, economic growth and stability are dominant in the politics and mentality of modern populations; that cohort effects are weak to non-existent; that political generational effects are rare and soon fade away; that family life cycle, if carefully delineated, has an impact across a wide range of attitudes and behavior. Most important, differences in national mobilizing structures shape both mass and elite responses to the dilemmas and problems of modern life. Assessing related images of modern society - 'the information age', the 'high-tech society' - the paper finds these equally misleading.' (author's abstract)Die Theorie der postindustriellen Gesellschaft und der postmaterialistischen Kultur sind - so die These des vorliegenden Arbeitspapiers - nicht in der Lage, die strukturellen Gemeinsamkeiten und die nationalen Differenzen der modernen 'Massengesellschaft' zu erklaeren. Die Beschreibungen des Strukturwandels durch diese Ansaetze sind oberflaechlich: Der Dienstleistungssektor ist zu heterogen, um daraus berufliche und industrielle Trends abzuleiten; die These von der technokratischen Dominanz ist ueberzogen und ignoriert die Bedeutung von Experten und Intellektuellen. Weiterhin bezweifelt der Autor den behaupteten Trend hin zu 'postmaterialistischen' Wertorientierungen. Die empirischen Studien, die diese Entwicklung zu belegen scheinen, kranken alle am Problem der Validitaet von Umfrageforschung. Gegenueber diesem Wertewandel behauptet der Autor die Persistenz der traditionellen Themen wie Sicherheit, Gleichheit, Angst vor Kriminalitaet, Wirtschaftswachstum und politische Stabilitaet in den modernen Gesellschaften. Dies zeigt sich daran, dass bei diesen Themen die Kohorteneffekte zwischen den Generationen schwach ausgepraegt sind. Insgesamt sind daher die im Titel genannten 'Zeitdiagnosen' eher irrefuehrend. (ICA)German title: Postindustrialismus und Postmaterialismus?: ein kritischer Blick auf die 'New Economy', das 'Informationszeitalter', die 'High Tech Society' und all dasAvailable from UuStB Koeln(38)-20040106420 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Factorization dynamics and Coxeter-Toda lattices

It is shown that the factorization relation on simple Lie groups with standard Poisson Lie structure restricted to Coxeter symplectic leaves gives an integrable dynamical system. This system can be regarded as a discretization of the Toda flow. In case of SL_n the integrals of the factorization dynamics are integrals of the relativistic Toda system. A substantial part of the paper is devoted to the study of symplectic leaves in simple complex Lie groups, its Borel subgroups and their doubles. (orig.)SIGLEAvailable from TIB Hannover: RR 1596(420) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Cluster formation in a stepping stone model with continuous, hierarchically structured sites

A stepping stone model with site space a continuous, hierarchical group is constructed via duality with a system of (delayed) coalescing 'stable' Levy processes. This model can be understood as a continuum limit of discrete state-space, two allele, genetics models with hierarchically structured resampling and migration. The existence of a process rescaling limit on suitable large space and time scales is established and interpreted in terms of the dynamics of cluster formation. This paper was inspired by recent work of Klenke. (orig.)Available from TIB Hannover: RR 5549(187)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Quantum discrete sine-Gordon model at roots of 1: integrable quantum system on the integrable classical background

The quantum discrete sine-Gordon model at roots of 1 is studied. It is shown that this model provides an example of an integrable quantum system in an integrable classical background. In particular, the spectrum of quantum integrals of motions in this model depends only on the values of integrals of motion of a background classical system. (orig.)Available from TIB Hannover: RR 1596(166) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman