Approximating the maximum ergodic average via periodic orbits

Let sigma: Sigma(A) -> Sigma(A) be a subshift of finite type, let M-sigma be the set of all sigma-invariant Borel probability measures on Sigma(A), and let f : Sigma(A) -> R be a Holder continuous observable. There exists at least one or-invariant measure A which maximizes integral f d mu. The following question was asked by B. R. Hunt, E. Ott and G. Yuan: how quickly can the maximum of the integrals integral f d mu be approximated by averages along periodic orbits of period less than p? We give an example of a Holder observable f for which this rate of approximation is slower than stretched-exponential in p

The influence of geomagnetic activity on polar cap absorption

Cosmic noise absorption data on polar cap analyzed for geomagnetic activit

Global flows or rural-urban connections? Temporality, public spaces and heterotopias in globalising Mumbai

Opposing certain dominant perspectives within urban studies, which give prominence to the role of capital in determining social space and urban social processes, there has been an emerging trend among scholars to develop Foucault's idea of heterotopia. This idea has been appropriated to explain spaces that have several levels or tiers of significance, meaning and relationships to other physical places and social spaces. This paper draws upon studies of and fieldwork from the Indian urban context and its evolution, linking these to larger processes of democratisation, social conflicts, and emancipatory struggles. It employs the idea of heterotopia to denote greater agency to class and non-class actors, groups and institutions, in the definition of urban visions and in the determination of urban spatial processes and spatially linked social processes. Various agentive groups and individual actors use the city and develop it for different social, political and economic purposes. For each of them, the city is an event that occurs (or is made to occur) in the specific evolutionary trajectory of their struggles for mobility and social emancipation, or possibly in their rise to dominance. Based on field research in the Indian city of Mumbai, this paper outlines the ways in which the study of this temporal dimension can provide key insights into the spatial, cultural, political and social implications of globalisation in Asian cities. At the same time, it further addresses rural-urban connections, networks and how these interact and intersect with global flows. To this effect, it maps the politics of rural-urban transitions and traces how they in turn give shape to the social agency of marginalised groups and classes in ways that are expressed in these groups’ uses of public space.Entgegen manchen in den Urban Studies weit verbreiteten Perspektiven, die die Rolle des Kapitals bei der Bestimmung des sozialen Raums und urbaner sozialer Prozesse in den Mittelpunkt stellen, wendet sich eine wachsende Anzahl von Forschern Foucaults Begriff der Heterotopie zu. Er dient dazu, Räume zu erklären, die mehrere Bedeutungs- und Sinnebenen aufweisen und in vielfacher Beziehung zu anderen physischen Orten und sozialen Räumen stehen. Das vorliegende Working Paper stützt sich auf Studien zur Entwicklung von städtischem Raum in Indien und setzt diese in Bezug zu größeren Demokratisierungsprozessen, sozialen Konflikten und Emanzipationsbewegungen. Der Begriff Heterotopie verdeutlicht, dass schicht- und nichtschichtspezifische Akteure, Gruppen und Institutionen bei der Definition urbaner Visionen sowie bei der Bestimmung urbaner räumlicher Prozesse und der damit verbundenen sozialen Prozesse stärker als Handelnde in Erscheinung treten. Verschiedene Gruppen und einzelne Akteure benutzen und entwickeln die Stadt zu unterschiedlichen sozialen, politischen und ökonomischen Zwecken. Sie betrachten die Stadt als ein Ereignis im spezifischen Verlauf ihrer jeweiligen Kämpfe um Mobilität und gesellschaftliche Emanzipation, fallweise auch ihres Aufstiegs an die Macht. Ausgehend von Feldforschung im indischen Mumbai wird herausgearbeitet, wie die Untersuchung dieser zeitlichen Dimension wichtige Einblicke in die räumlichen, kulturellen, politischen und sozialen Auswirkungen der Globalisierung in den Städten Asiens eröffnen kann. Darüber hinaus werden die Beziehungen und Netzwerke zwischen dem ländlichen und dem städtischen Raum angesprochen und deren Berührungspunkte und Wechselbeziehungen mit globalen Strömen beschrieben. Dazu wird anhand der Politik des Übergangs vom ruralen zum urbanen Raum aufgezeigt, wie diese Politik das soziale Handeln marginalisierter Gruppen und Schichten und deren Nutzung des öffentlichen Raums prägt

Spontaneous Time Asymmetry due to Horizon

We show that quantized matter fields in the presence of background metrics with Horizon exhibit spontaneous time asymmetry. All quantized matter fields have to vanish at the horizon. Some phenemenological applications of this in the context of black holes and early universe are considered.Comment: 4 pages, Revte

Gender and Social Capital Mediated Technology Adoption

This study explores gender-differentiated benefits from the social capital buildup in technology uptake, and the decision-making patterns of men and women with respect to production, consumption and household task; and allocation of resources. The background research examined women’s role in developing social capital, and research developed a case study of the groundnut producing areas of Maharashtra in western India, and compared ‘with’ and ‘without’ technology situations, and ‘before’ and ‘after’ situations in relation to the package of groundnut production technology introduced in the region in 1987. The paper addresses three aspects: (1) social networks in technology adoption, (2) the gender-based activity pattern, and (3) build-up of social capital leading to improvements in the welfare of farmers and the farming community with a gender perspective. Available evidence suggests substantial differences in networks of men and women, particularly in composition. The evidence suggests that men belong to more formal networks reflecting their employment or occupation status, while women have more informal networks that are centered on family and kin. Findings show that women who are engaged in agriculture and allied activities develop bonding social capital characterized by strong bonds such as that found among family members or among members of an ethnic group. Men who are engaged in agriculture, on the other hand, develop bridging social capital characterized by weaker, less dense but more crosscutting ties such as with farmers, acquaintances, friends from different ethnic groups and friends of friends. Women’s employment opportunities significantly improved with the introduction of technology. Finally, the study concludes that while technology development and exchange can build upon social capital as a means of empowering women, much more needs to be learned about the approaches that foster build-up of social capital.

Biao, X., Yeoh, B.S.A., Toyota, M. (Eds.) Return: Nationalizing Transnational Mobility in Asia. Durham: Duke University Press, 2013.

Book review

High resolution spectroscopy of the high velocity hot post-AGB star LS III +52 24 (IRAS 22023+5249)

The first high-resolution (R~50,000) optical spectrum of the B-type star, LS III +52 24, identified as the optical counterpart of the hot post-AGB candidate IRAS 22023+5249 (I22023) is presented. We report the detailed identifications of the observed absorption and emission features in the full wavelength range (4290-9015 A) as well as the atmospheric parameters and photospheric abundances (under the Local Thermodinamic Equilibrium approximation) for the first time. The nebular parameters (Te, Ne) are also derived. We estimate Teff=24,000 K, log g=3.0, xi=7 kms-1 and the derived abundances indicate a slightly metal-deficient evolved star with C/O<1. The observed P-Cygni profiles of hydrogen and helium clearly indicate on-going post-AGB mass loss. The presence of [N II] and [S II] lines and the non-detection of [O III] indicate that photoionisation has just started. The observed spectral features, large heliocentric radial velocity, atmospheric parameters, and chemical composition indicate that I22023 is an evolved post-AGB star belonging to the old disk population. The derived nebular parameters (Te=7000 K, Ne=1.2x104 cm-3) also suggest that I22023 may be evolving into a compact, young low-excitation Planetary Nebula. Our optical spectroscopic analysis together with the recent Spitzer detection of double-dust chemistry (the simultaneous presence of carbonaceous molecules and amorphous silicates) in I22023 and other B-type post-AGB candidates may point to a binary system with a dusty disk as the stellar origin common to the hot post-AGB stars with O-rich central stars.Comment: Accepted for publication in MNRAS (22 pages, 4 figures, and 8 tables). arXiv admin note: substantial text overlap with arXiv:0707.059

The expressive movements of the bonnet macaque

A bonnet troop inhabiting Lal Bagh, Bangalore (Hafeezur Rahaman & Parthasarathy, 1967) was exclusively studied for its communicative behavior. The whole system of the bonnet organization is based on composite expressions. Depending on situations, individual signals or a complex of them involving tactile, visual, auditory, and olfactory are passed from one individual to the other. Among tactile signals the most important one is the grooming; among visual the body movement, more particularly the face and jaws; among auditory the groaning and shrieking; among olfactory the sniffing. Analysis of such a study reveals that the bonnet monkeys have a communicative system and an organization of their own, which though principally are the same as in other primates, do entail a few minor differences. These features though primitive from the standards of human consideration, are developed to their full advantage, but still remain at a primitive level. By far, the greatest part of the whole system of communication seems to be devoted to the organization, of the social behavior of the group, to dominance and subordination, the maintenance of peace and cohesion of the group, reproduction and care of the young (Marler, 1965)