Let F be a free group of rank N ≥ 2, let µ be a geodesic current on F and let T be an R-tree with a very small isometric action of F. We prove that the geometric intersection number 〈T, µ 〉 is equal to zero if and only if the support of µ is contained in the dual algebraic lamination L 2 (T) of T. Applying this result, we obtain a generalization of a theorem of Francaviglia regarding length spectrum compactness for currents with full support. We use the main result to obtain ”unique ergodicity type properties for the attracting and repelling fixed points of a toroidal iwip elements of Out(F) when acting both on the compactified Outer Space and on the projectivized space of currents. We also show that the some of the translation length functions of any two ”sufficiently transverse” very small F-trees is bilipschitz equivalent to the translation length function of an interior point of the Outer space. As another application, we define the notion of a filling element in F and prove that filling elements are ”nearly generic ” in F. We also apply our results t
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.