Explicit bounds on integrals of eigenfunctions over curves in surfaces of nonpositive curvature

Let $(M,g)$ be a compact Riemannian surface with nonpositive sectional curvature and let $\gamma$ be a closed geodesic in $M$. And let $e_\lambda$ be an $L^2$-normalized eigenfunction of the Laplace-Beltrami operator $\Delta_g$ with $-\Delta_g e_\lambda = \lambda^2 e_\lambda$. Sogge, Xi, and Zhang showed using the Gauss-Bonnet theorem that $$\int_\gamma e_\lambda \, ds = O((\log\lambda)^{-1/2}),$$ an improvement over the general $O(1)$ bound. We show this integral enjoys the same decay for a wide variety of curves, where $M$ has nonpositive sectional curvature. These are the curves $\gamma$ whose geodesic curvature avoids, pointwise, the geodesic curvature of circles of infinite radius tangent to $\gamma$.Comment: 23 pages, 3 figures, arXiv admin note: text overlap with arXiv:1702.0355

Direct measurement of xenon flashtube opacity

Opacity measurement of xenon flash tube - optical mase

Application of DOT-MORSE coupling to the analysis of three-dimensional SNAP shielding problems

The use of discrete ordinates and Monte Carlo techniques to solve radiation transport problems is discussed. A general discussion of two possible coupling schemes is given for the two methods. The calculation of the reactor radiation scattered from a docked service and command module is used as an example of coupling discrete ordinates (DOT) and Monte Carlo (MORSE) calculations

The Scholarly Communication Problem: Why Open Access is Necessary – A Transatlantic Perspective –

This article was written to raise awareness among researchers in the Open Access movement and share KU’s experience as a leader in Open Access policy. First published in September 2010 in the national daily paper Delo (Ljubljana, Slovenia) [http://hdl.handle.net/1808/6646], the piece has appeared in translation in newspapers in Croatia, Romania, Serbia, and Ukraine, among others