Analyses of halo shapes for disc galaxies are said to give incongruous results. I point out that the modified dynamics (MOND) predicts for disc galaxies a distribution of fictitious dark matter that comprises two components: a pure disc and a rounder halo. The former dominates the true disc in regions of small accelerations, where it controls the z-dynamics in the disc (disc flaring etc.); it h...

To help the prospective observer take full advantage of the mid-IR capability of Gemini South, we characterize a key aspect of the mid-IR performance of the 8-meter telescope at Gemini-S, namely, the appearance and stability of its delivered mid-IR image profiles, with the goal of demonstrating that it can be used with a level of precision not used before. About 2000 images obtained with T-ReCS...

We both theoretically and experimentally examine the behavior of the first- and the second-order rainbows produced by a normally illuminated glass rod, which has a nearly elliptical cross section, as it is rotated about its major axis. We decompose the measured rainbow angle, taken as a function of the rod's rotation angle, into a Fourier series and find that the rod's refractive index, average...

In this publication we present the results of a detailed study into directly written multimode waveguides for astronomical applications. We show that waveguides up to 100 μm across can be inscribed with the cumulative heating form of this technique. The waveguides have 2 concentric guiding regions which are elliptical; a core that has an average ellipticity of 1.1±0.1 and an outer cladding with...

The use of bichromatic counter-rotating laser field is known to generate high-order harmonics with non-zero ellipticity. By combining such a plasmonic-enhanced spatially inhomogeneous field, we propose way influence the sub-cycle dynamics high-harmonic generation process. Using numerical solution time-dependent Schr{\"o}dinger equation combined classical trajectory Monte Carlo simulations, show...

Searches for continuous gravitational waves from \textit{unknown} Galactic neutron stars provide limits on the shapes of stars. A rotating star will produce if asymmetric deformations exist in its structure that are characterized by star's ellipticity. In this study, we use a simple model spatial and spin distribution to estimate total number probed, using waves, given upper limit This may help...

We consider hyperelastic stored energy functions in Rn×n that are isotropic. We give necessary and sufficient conditions for the ellipticity of such functions. The present article is essentially a review of recent results on the subject.