4 papers
Two-sided bounds for dihedral angle sums of path and 4-ball tetrahedra
Sergey Korotov, Michal Krizek
A tetrahedron is called a path tetrahedron, if it has three mutually orthogonal edges that do not intersect at a single point. A tetrahedron is called a 4-ball tetrahedron, if ther…
An alternative explanation of the orbital expansion of Titan and other bodies in the Solar system
Michal Křížek, Vesselin G. Gueorguiev, André Maeder
Recently it was found from Cassini data that the mean recession speed of Titan from Saturn is cm/yr which corresponds to a tidal quality factor of Saturn $Q\cong 10…
Factorization of CP-rank-3 completely positive matrices
Jan Brandts, Michal Krizek
A symmetric positive semi-definite matrix A is called completely positive if there exists a matrix B with nonnegative entries such that A=BB^T. If B is such a matrix with a minimal…
There are only two nonobtuse binary triangulations of the unit -cube
Jan Brandts, Sander Dijkhuis, Vincent de Haan +1
Triangulations of the cube into a minimal number of simplices without additional vertices have been studied by several authors over the past decades. For this so-ca…