6 papers
Constructing the -gon, the first step: the 641-gon
Helmut Ruhland
In an article S. Adlaj showed the construction of the -gon ( a Fermat prime). Extending the authors method to cases, where the multiplicative group is not of or…
On two Abelian Groups Related to the Galois Top
Helmut Ruhland
In mathematical physics the Galois top, introduced by S. Adlaj, possesses a fixed point on one of two Galois axes through its center of mass. This heavy top has two algebraic motio…
Unified constructions of the regular Heptagon, Triskaidecagon and Heptadecagon
Helmut Ruhland
Constructions of regular heptagon and triskaidecagon by trisection of an angle are well known. An elegant construction of the heptagon by S. Adlaj shows a 3-fold symmetry related t…
No new lower bound for the density of planar Sets avoiding Unit Distances
Helmut Ruhland
In a recently published article by G. Ambrus et al. a new \emph{upper bound} for the density of an unit avoiding, periodic set is given as , the first upper bound .…
Cubic equations with 2 Roots in the interval
Helmut Ruhland
The conditions for cubic equations, to have 3 real roots and 2 of the roots lie in the closed interval are given. These conditions are visualized. This question arises in…
Families of lattices with an unbounded number of unit vectors
Helmut Ruhland
3 families of 4-dimensional lattices are defined. Each lattice is defined by 2 quadratic extensions and has a \emph{finite} number of unit…