Thermal kinetic inductance detectors for ground-based millimeter-wave cosmology

We show measurements of thermal kinetic inductance detectors (TKID) intended for millimeter wave cosmology in the 200-300 GHz atmospheric window. The TKID is a type of bolometer which uses the kinetic inductance of a superconducting resonator to measure the temperature of the thermally isolated bolometer island. We measure bolometer thermal conductance, time constant and noise equivalent power. We also measure the quality factor of our resonators as the bath temperature varies to show they are limited by effects consistent with coupling to two level systems.Comment: 8 pages, 4 figures. Submitted to Journal of Low Temperature Physic

Extremal Presentations for Classical Lie Algebras

The long-root elements in Lie algebras of Chevalley type have been well studied and can be characterized as extremal elements, that is, elements $x$ such that the image of (\ad x)^2 lies in the subspace spanned by $x$. In this paper, assuming an algebraically closed base field of characteristic not 2, we find presentations of the Lie algebras of classical Chevalley type by means of minimal sets of extremal generators. The relations are described by simple graphs on the sets. For example, for $C_n$ the graph is a path of length $2n$, and for $A_n$ the graph is the triangle connected to a path of length $n-3$.Comment: 26 pages, 6 figure

Evolutionary multi-stage financial scenario tree generation

Multi-stage financial decision optimization under uncertainty depends on a careful numerical approximation of the underlying stochastic process, which describes the future returns of the selected assets or asset categories. Various approaches towards an optimal generation of discrete-time, discrete-state approximations (represented as scenario trees) have been suggested in the literature. In this paper, a new evolutionary algorithm to create scenario trees for multi-stage financial optimization models will be presented. Numerical results and implementation details conclude the paper