Renormalized g-log (g) double expansion for the invariant φ4 trajectory in three dimensions Original Research Article

We study the invariant unstable manifold of the trivial renormalization group fixed point tangent to the φ4 vertex in three dimensions. We parametrize it by a running φ4 coupling with linear step β-function. It is shown to have a renormalized double expansion in the running coupling and its logarithm.