Density waves in strongly correlated quantum chains

We review exact numerical results for one-dimensional quantum systems with half-filled bands. The topics covered include Peierls transitions in Holstein, Fr\"ohlich, Su-Schrieffer-Heeger, and Heisenberg models with quantum phonons, competing fermion-boson and fermion-fermion interactions, as well as symmetry-protected topological states in fermion and anyon models.Comment: 15 pages, 17 figures; focused review article for an EPJ B topical issue on "Coexistence of long-range orders in low-dimensional systems". Comments welcome

Labour markets in Poland and Hungary five years from the start of transition: Evidence from monthly data

This paper presents error correction estimates of a simple interdependent model of the labour market using monthly data over 1990-1994 for the industrial sector in Poland and Hungary. The aim is to investigate three issues in the performance of labour markets during transition. First, is there a stable labour market equilibrium or do high unemployment rates across the region indicate hysteresis? Second, has the intensity of employment adjustment increased with progress in institutional reforms that strengthened corporate governance at the enterprise level? Third, what governs the evolution of real wages and to what extent is there evidence for strong insider power in the labour market? The results reveal striking differences between Poland and Hungary. The former exhibits hysteresis and evidence for considerable insider power while the latter has experienced adjustment towards a stable labour market equilibrium. The intensity of adjustment, however, is high in both countries over the sample period and fails to respond to the initiation of institutional reforms.Hysteresis,Adjustment Intensity,Insider Power

Making sense of the J-curve: Capital utilisation, output, and total factor productivity in Polish industry 1990 - 1993

The economies of Central and Eastern Europe are undergoing a period of rapid structural change. The general pattern confirms to the J-curve anticipated by several observers at the start of transition. This paper conceptualises the J-curve as the result of a combination of two factors. First, real energy price increases render parts of the capital stock obsolete, due to complementarity between capital and energy in the short run. Second, demand shifts and to a lesser extent efficiency improvements induced by increases in competition cause dramatic changes in total factor productivity. The paper shows for the case of Polish industry that 43 per cent of the capital stock was rendered obsolete over the 1990-1993 period. Total factor productivity fell by 11 per cent in 1990 but had increased to 17 per cent above the 1989 level by 1993. As the capital stock is gradually rebuilt, improvements in efficiency will guarantee an output level higher than before the start of transition.capital ultilisation,efficiency,J-curve,Poland

HQE²R - an European assessment tool towards sustainable neighbourhoods

The Institute of Ecological and Regional Development (IOER) is the German contractor of "Sustainable Renovation of Buildings for Sustainable Neighbourhoods" (HQE²R - Haute Qualité Environnementale et Economique Réhabilitation), partially funded by the EC under the Fifth Framework Programme. The project started in July 2001 and will continue until December 2003. Coordinated by CSTB France (Centre Scientifique et Technique du Bâtiment) it combines research and demonstration aspects by cooperation of nine European partners in connection with 15 international case studies. The project's objective is to develop a new methodology and the necessary tools to promote sustainable development and quality of life on the crucial and likewise challenging level of urban neighbourhoods. HQE²R will be a decision support tool for municipalities and their local partners, focussing on the aims of inhabitants and users of neighbourhoods. In its integrated approach it is meant to be generally applicable in Europe. The project is using the case studies as model neighbourhoods for the methodology to be provided. In Germany the case study will be carried out in Dresden-Loebtau. Loebtau residential area is a traditional workers quarter, cut off from the city-centre by large roads, railroad infrastructure and extensive brownfield sites. Although renovation works have been supported by declaring districts as "rehabilitation areas", Loebtau is facing a high residential vacancy. The challenge is how the considerable success in renovations achieved on building scale can be extended into sustainable neighbourhood development. Main targets therefore are to identify urban development measures towards sustainable development, especially in socio-economic terms and to find an appropriate methodology to estimate or assess the environmental effects arising from different combinations of socio-economic, urban planning and urban infrastructure measures.At ERSA 2002 we would be glad to present the methodology of neighbourhood analysis developed within the HQE²R project. The approach will be demonstrated by the case study of Dresden-Loebtau, showing how the application of the instrument has been carried out in practice. Furthermore the assessment and decision support tool to improve the quality of measures towards a sustainable neighbourhood can be presented in its state of the art, at this time still being under development.

Vertical structures induced by embedded moonlets in Saturn's rings: the gap region

We study the vertical extent of propeller structures in Saturn's rings. Our focus lies on the gap region of the propeller and on non-inclined propeller moonlets. In order to describe the vertical structure of propellers we extend the model of Spahn and Sremcevic (2000) to include the vertical direction. We find that the gravitational interaction of ring particles with the non-inclined moonlet does not induce considerable vertical excursions of ring particles, but causes a considerable thermal motion in the ring plane. We expect ring particle collisions to partly convert the lateral induced thermal motion into vertical excursions of ring particles. For the gap region of the propeller, we calculate gap averaged propeller heights on the order of 0.7 Hill radii, which is of the order of the moonlet radius. In our model the propeller height decreases exponentially until viscous heating and collisional cooling balance. We estimate Hill radii of 370m and 615m for the propellers Earhart and Bleriot. Our model predicts about 120km for the azimuthal extent of the Earhart propeller at Saturn's 2009 equinox, being consistent with values determined from Cassini images

Random Moment Problems under Constraints

We investigate moment sequences of probability measures on $E\subset\mathbb{R}$ under constraints of certain moments being fixed. This corresponds to studying sections of $n$-th moment spaces, i.e. the spaces of moment sequences of order $n$. By equipping these sections with the uniform or more general probability distributions, we manage to give for large $n$ precise results on the (probabilistic) barycenters of moment space sections and the fluctuations of random moments around these barycenters. The measures associated to the barycenters belong to the Bernstein-Szeg\H{o} class and show strong universal behavior. We prove Gaussian fluctuations and moderate and large deviations principles. Furthermore, we demonstrate how fixing moments by a constraint leads to breaking the connection between random moments and random matrices.Comment: 43 page