文摘
We establish that the spectral multiplier \(m({G_\alpha })\) associated to the differential operator $$G_\alpha = - \Delta _x + \sum\limits_{j = 1}^m {\frac{{\alpha _j^2 - 1/4}} {{x_j^2 }} - \left| x \right|^2 \Delta _y on (0,\infty )^m \times \mathbb{R}^n ,} $$, which we call the Bessel-Grushin operator, is of weak type (1, 1) provided that M is in a suitable local Sobolev space. In order to do this, we prove a suitable weighted Plancherel estimate. Also, we study L p -boundedness properties of Riesz transforms associated to \({G_\alpha }\) in the case n = 1. The first, second, and the fourth authors are partially supported by MTM2013/44357-P.