Grušin operators, Riesz transforms and nilpotent Lie groups

Derek W Robinson, Adam Sikora

We establish that the Riesz transforms of all orders corresponding to the Grušin operator $H_N=-{\nabla }_x^2-|x{|}^{2N}{\nabla }_y^2$, and the first-order operators $(\nabla_{x},x^ν…