Parallel lines are very important objects in Euclid plane geometry and its behaviors can be gotten by one's intuition. But in a planar map geometry, a kind of the Smarandache geometries, the situation is complex since it may contains elliptic or hyperbolic points. This paper concentrates on the behaviors of parallel bundles in planar map geometries, a generalization of parallel lines in plane g...

casimir forces of massive ferrnionic dirac fields are calculated for parallel plates geometry in spatial space with dimension d and imposing bag model boundary conditions. it is shown that in the range of ma>>l where m is mass of fields quanta and a is the separation distance of the plates, it is equal to massive bosonic fields casimir force for each degree of freedom. we argue this equality ex...