  We study the 2-loop part of the rational Kontsevich integral of a knot in an
integer homology sphere. We give a general formula which explains how the
2-loop part of the Kontsevich integral of a knot changes after surgery on a
single clasper whose leaves are not linked to the knot. As an application, we
relate this formula with a conjecture of L. Rozansky about integrality of the
2-loop polynomial of a knot.

Geometric Topology