Nonminimally coupled topological-defect boson stars: Static solutions

We consider spherically symmetric static composite structures consisting of a boson star and a global monopole, minimally or non-minimally coupled to the general relativistic gravitational field. In the non-minimally coupled case, Marunovic and Murkovic have shown that these objects, so-called boson D-stars, can be sufficiently gravitationally compact so as to potentially mimic black holes. Here, we present the results of an extensive numerical parameter space survey which reveals additional new and unexpected phenomenology in the model. In particular, focusing on families of boson D-stars which are parameterized by the central amplitude of the boson field, we find configurations for both the minimally and non-minimally coupled cases that contain one or more shells of bosonic matter located far from the origin. In parameter space, each shell spontaneously appears as one tunes through some critical central amplitude of the boson field. In some cases the shells apparently materialize at spatial infinity: in these instances their areal radii are observed to obey a universal scaling law in the vicinity of the critical amplitude. We derive this law from the equations of motion and the asymptotic behavior of the fields.Comment: 17 pages, 24 figure

Minimax studies

Effect of nonzero initial conditions on selection of minimax controllers for large launch vehicles and extremal bounded amplitude bounded rate inputs to linear system

Laser diode initiated detonators for space applications

Ensign Bickford Aerospace Company (EBAC) has over ten years of experience in the design and development of laser ordnance systems. Recent efforts have focused on the development of laser diode ordnance systems for space applications. Because the laser initiated detonators contain only insensitive secondary explosives, a high degree of system safety is achieved. Typical performance characteristics of a laser diode initiated detonator are described in this paper, including all-fire level, function time, and output. A finite difference model used at EBAC to predict detonator performance, is described and calculated results are compared to experimental data. Finally, the use of statistically designed experiments to evaluate performance of laser initiated detonators is discussed