3 papers
math.AT2005
The Extension of Knot Groups to Tangles
John Armstrong
The extension of the knot group to the category of tangles is introduced via a new category-theoretic construction. Through this presentation, a new avenue of…
math.DG2001
Local models and integrability of certain almost Kahler 4-manifolds
Vestislav Apostolov, John Armstrong, Tedi Draghici
We classify, up to a local isometry, all non-Kahler almost Kahler 4-manifolds for which the fundamental 2-form is an eigenform of the Weyl tensor, and whose Ricci tensor is invaria…
math.DG1999
Local rigidity of certain classes of almost Kahler 4-manifolds
Vestislav Apostolov, John Armstrong, Tedi Draghici
We show that any non-Kahler, almost Kahler 4-manifold for which both the Ricci and the Weyl curvatures have the same algebraic symmetries as they have for a Kahler metric is locall…