Abstract The purpose of this paper is to compare the notion a Grzegorczyk point introduced in [19] (and thoroughly investigated [3, 14, 16, 18]) standard notions filter Boolean algebras and round contact algebras. In particular, we points filters ultrafilters atomic atomless We also prove how certain extra axiom influences topological spaces for Last but not least, do refrain from philosophical...

We analyse Lieb–kagomé model, a three-band model with contact points showing particular examples of the merging Dirac points. prove that eigenstates can be parametrized in classification surface, which is hypersurface 4-dimension space. This surface powerful device giving topological properties energy band structure; analysis its fundamental group proves all singularities structure characterize...

In an effort to study the stability of contact lines in fluids, we consider dynamics a drop incompressible viscous Stokes fluid evolving above one-dimensional flat surface under influence gravity. This is free boundary problem: interface between on and air (modeled by trivial fluid) move experiences capillary forces. The three-phase where fluid, air, solid vessel wall meet known as point, angle...