A formula for topology/deformations and its significance

Ruth Lawrence, Dennis Sullivan

The formula is $\partial e=({\mathrm{ad}}_e)b+{\sum }_{i=0}^{\infty }\frac{B_i}{i!}({\mathrm{ad}}_e{)}^i(b-a),$ with $\partial a+\frac{1}{2}[a,a]=0$ and $\partial b+\frac{1}{2}[b,b]=0$, where $…