L1-determined ideals in group algebras of exponential Lie groups

A locally compact group $G$ is said to be $\ast$-regular if the natural map \Psi:\Prim C^\ast(G)\to\Prim_{\ast} L^1(G) is a homeomorphism with respect to the Jacobson topologies on the primitive ideal spaces \Prim C^\ast(G) and \Prim_{\ast} L^1(G). In 1980 J. Boidol characterized the $\ast$-regular ones among all exponential Lie groups by a purely algebraic condition. In this article we introduce the notion of $L^1$-determined ideals in order to discuss the weaker property of primitive $\ast$-regularity. We give two sufficient criteria for closed ideals $I$ of $C^\ast(G)$ to be $L^1$-determined. Herefrom we deduce a strategy to prove that a given exponential Lie group is primitive $\ast$-regular. The author proved in his thesis that all exponential Lie groups of dimension $\le 7$ have this property. So far no counter-example is known. Here we discuss the example $G=B_5$, the only critical one in dimension $\le 5$

Wavelength-selectable laser emission from a multistripe array grating integrated cavity laser

We report laser operation of a multistripe array grating integrated cavity (MAGIC) laser in which the wavelength of the emission from a single output stripe is chosen by selectively injection pumping a second stripe. We demonstrate a device that lases in the 1.5 µm fiber band at 15 wavelengths, evenly spaced by ~2 nm. The single-output/wavelength-selectable operation, together with the accurate predefinition of the lasing wavelengths, makes the MAGIC laser a very attractive candidate for use in multiwavelength networks

Finitness of the basic intersection cohomology of a Killing foliation

We prove that the basic intersection cohomology ${I H}^{^{*}}_{_{\bar{p}}}{(M/\mathcal{F})},$ where $\mathcal{F}$ is the singular foliation determined by an isometric action of a Lie group $G$ on the compact manifold $M$, is finite dimensional

Intra-party decision-making in contemporary Europe: improving representation or ruling with empty shells?

Political observers agree that parties in European parliamentary democracies are more likely than previously to give party members opportunities to vote in decisions about party policies or personnel. Observers are less agreed about the implications of these apparent procedural trends. Some, including Peter Mair, saw them as evidence of the hollowing-out of party democracies; others have seen them as enhancing citizens’ opportunities for meaningful political participation. Because this is ultimately an empirical question as well as a normative one, these radically conflicting interpretations make it crucial to examine which interpretation is best supported by usage to date This is the task we undertake in this article. We use data from the Political Party Database Project (PPDB) to investigate the extent to which parties in 26 European countries have adopted and employed intra-party ballots. We also ask whether there is evidence that such procedures are changing intra-party relationships. We find that balloting of party members is indeed widely used, but it is by no means universal. We find much less support for the implication that such ballots are associated with less competitive contests, or that the new devices are generally used in ways that devalue party-member bonds

Monolithic WDM Sources And Detectors For The Long Wavelength Fiber Band Based On An InP Grating Multiplexer/demultiplexer

Wavelength Division Multiplexed (WDM) networks are currently attracting considerable attention worldwide. Applications envisaged are wide-ranging - from computer back-plane interconnects and the telephone local loop, through local- and metropolitan- area networks, to wide-area networks involving advanced wavelength routing schemes [1, 2]

The MAGIC Laser: a Monolithic WDM Source

We discuss the Multi-stripe Array Grating Integrated Cavity (MAGIC) Laser: a multi-wavelength laser formed by monolithically integrating a diffraction grating and an array of active stripes in a planar semiconductor waveguide cavity. Recent results will be presented

The MAGIC Laser: a Monolithic WDM Source

We discuss the Multi-stripe Array Grating Integrated Cavity (MAGIC) Laser: a multi-wavelength laser formed by monolithically integrating a diffraction grating and an array of active stripes in a planar semiconductor waveguide cavity. Recent results will be presented

Party rules, party resources, and the politics of parliamentary democracies: how parties organize in the 21st Century

This article introduces the first findings of the Political Party Database (PPDB) project, a major survey of party organizations in parliamentary and semi-presidential democracies. The project’s first round of data covers 122 parties in 19 countries. In this paper we describe the scope of the database, then investigate what it tells us about contemporary party organization in these countries, focussing on parties’ resources, structures and internal decision-making. We examine organizational patterns by country and party family, and where possible we make temporal comparisons with older datasets. Our analyses suggest a remarkable coexistence of uniformity and diversity. In terms of the major organizational resources on which parties can draw, such as members, staff and finance, the new evidence largely confirms the continuation of trends identified in previous research: i.e., declining membership, but enhanced financial resources and more paid staff. We also find remarkable uniformity regarding the core architecture of party organizations. At the same time, however, we find substantial variation between countries and party families in terms of their internal processes, with particular regard to how internally democratic they are, and in the forms that this democratization takes