Zeeman-type dragging in the Kerr--Newman and NUT spacetimes

In this communication we discuss two distinct Zeeman-type gravitomagnetic effects deserving attention since they can be easily characterized in their exact form, not via approximation procedures. Some observations are also made on gravitoelectric effects.Comment: 5 pages, a talk delivered at the 11th Marcel Grossmann Meeting (2006

Urban space and pervasive systems

In this paper we present an early approach for developing a theoretical framework and understanding for designing pervasive systems as an integral part of the urban landscape. The research will be conducted in the city of Bath as part of the CityWare project, in a heritage environment with tourist attractions. Here we propose to investigate the application of research methods based on Space Syntax, which encompasses a set of theories and techniques for the analysis of space and spatial patterns, as a framework for understanding the complex relationship between pervasive systems, urban space and society in general; and the impact of the deployment of pervasive systems on people’s relationships to heritage, and to each other in particular

Quasinormal frequencies of asymptotically flat two-dimensional black holes

We discuss whether the minimally coupled massless Klein-Gordon and Dirac fields have well defined quasinormal modes in single horizon, asymptotically flat two-dimensional black holes. To get the result we solve the equations of motion in the massless limit and we also calculate the effective potentials of Schrodinger type equations. Furthermore we calculate exactly the quasinormal frequencies of the Dirac field propagating in the two-dimensional uncharged Witten black hole. We compare our results on its quasinormal frequencies with other already published.Comment: 12 pages. Accepted for publication in Gen. Rel. and Gra