$L^p$ spherical multipliers on homogeneous trees
  We characterise, for each $p$ in $[1,\infty) \setminus \{2\}$, the class of $L^p$ spherical multipliers on homogeneous trees in terms of $L^p$ Fourier multipliers on the torus. 
Dario Celotto, Stefano Meda, B{\l}a\.zej Wr\'obel
math.FA