On surgery curves for genus one slice knots

If a knot K bounds a genus one Seifert surface F in the 3-sphere and F contains an essential simple closed curve alpha that has induced framing 0 and is smoothly slice, then K is smoothly slice. Conjecturally, the converse holds. It is known that if K is slice, then there are strong constraints on the algebraic concordance class of such alpha, and it was thought that these constraints might imply that alpha is at least algebraically slice. We present a counterexample; in the process we answer negatively a question of Cooper and relate the result to a problem of Kauffman. Results of this paper depend on the interplay between the Casson-Gordon invariants of K and algebraic invariants of alpha.Comment: 17 pages, 1 figure. Typographical correction

The nonorientable four-genus of knots

We develop obstructions to a knot K in the 3-sphere bounding a smooth punctured Klein bottle in the 4-ball. The simplest of these is based on the linking form of the 2-fold branched cover of the 3-sphere branched over K. Stronger obstructions are based on the Ozsvath-Szabo correction term in Heegaard-Floer homology, along with the G-signature theorem and the Guillou-Marin generalization of Rokhlin's theorem. We also apply Casson-Gordon theory to show that for every n greater than one there exists a knot that does not bound a topologically embedded nonorientable ribbon surface F in the 4-ball with first Betti number less than n.Comment: 20 pages; expository change

Continental shift? An analysis of convergence trends in European real estate equities

European economic and political integration have been recognised as having implications for patterns of performance in national real estate and capital markets and have generated a wide body of research and commentary. In 1999, progress towards monetary integration within the European Union culminated in the introduction of a common currency and monetary policy. This paper investigates the effects of this ‘event’ on the behaviour of stock returns in European real estate companies. A range of statistical tests is applied to the performance of European property companies to test for changes in segmentation, co-movement and causality. The results suggest that, relative to the wider equity markets, the dispersion of performance is higher, correlations are lower, a common contemporaneous factor has much lower explanatory power whilst lead-lag relationships are stronger. Consequently, the evidence of transmission of monetary integration to real estate securities is less noticeable than to general securities. Less and slower integration is attributed to the relatively small size of the real estate securities market and the local and national nature of the majority of the companies’ portfolios

Distributing program entities in Ada

In any discussion of distributing programs and entities of programs written in a high order language (HOL), certain issues need to be included because they are generally independent of the particular language involved and have a direct impact on the feasibility of distribution. Of special interest is the distribution of Ada program entities, but many of the issues involved are not specific to Ada and would require resolution whether written in PASCAL, PL/1, Concurrent PASCAL, HAL/S, or any language which provides similar functionality. The following sections will enumerate some of these issues, and will show in what ways they relate to Ada. Also, some (but by no means all) of the issues involved in the distribution of Ada programs and program entities will be discussed

The stability of interfaces in fluidised beds

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Continental Shift? An Analysis of Convergence Trends in European Real Estate Equities

This paper investigates the effects of European monetary integration on the behavior of stock returns in European real estate companies from the perspective of a dollar-denominated investor. A range of statistical tests is applied to assess changes in segmentation, co-movement and causality. The results suggest that, relative to the wider equity markets, the dispersion of performance is higher, correlations are lower, a common contemporaneous factor has much lower explanatory power whilst lead-lag relationships are stronger. Less and slower integration is attributed to the relatively small size of the real estate securities market and the local nature of many real estate companies’ portfolios.