Heat kernel expansion for higher order minimal and nonminimal operators
Heat kernel expansion for higher order minimal and nonminimal operators
We build a systematic calculational method for the covariant expansion of the two-point heat kernel $\stackrel{^}{K}(\ensuremath{\tau}|x,{x}^{\ensuremath{'}})$ for generic minimal and nonminimal differential operators of any order. This is the expansion in powers of dimensional background field objects---the coefficients of the operator and the corresponding spacetime and vector bundle curvatures, suitable …