FeynCalc manual (development version)

DotExpand

DotExpand[exp] expands dot products in exp.

See also

Overview, DOT, DotSimplify, DeclareNonCommutative, UnDeclareNonCommutative

Examples

DOT[a x + b y + c z, d + e + f] 
 
DotExpand[%]

(ax+by+cz).(d+e+f)(a x+b y+c z).(d+e+f)

adx+aex+afx+bdy+bey+bfy+cdz+cez+cfza d x+a e x+a f x+b d y+b e y+b f y+c d z+c e z+c f z

DeclareNonCommutative /@ {a, b, c, d, e, f}; 
 
DotExpand[DOT[a x + b y + c z, d + e + f]]

xa.d+xa.e+xa.f+yb.d+yb.e+yb.f+zc.d+zc.e+zc.fx a.d+x a.e+x a.f+y b.d+y b.e+y b.f+z c.d+z c.e+z c.f

UnDeclareNonCommutative /@ {a, b, c, d, e, f}; 
 
DotExpand[DOT[a x + b y + c z, d + e + f]]

adx+aex+afx+bdy+bey+bfy+cdz+cez+cfza d x+a e x+a f x+b d y+b e y+b f y+c d z+c e z+c f z