O třetím Hilbertově problému
On Brocard points in the isotropic plane.
On cyclic curves in the Euclidean n-space.
On the finite blocking property
A planar polygonal billiard is said to have the finite blocking property if for every pair of points in there exists a finite number of “blocking” points such that every billiard trajectory from to meets one of the ’s. Generalizing our construction of a counter-example to a theorem of Hiemer and Snurnikov, we show that the only regular polygons that have the finite blocking property are the square, the equilateral triangle and the hexagon. Then we extend this result to translation surfaces....
On the Representation and Multiplication of Basic Alternating Cycle Matrices