On the translation invariant operators in ell^p(mathbb{Z}^d)

In this paper we study boundedness of translation invariant operators in the discrete space $\ell^p(\mathbb{Z}^d)$. In this context a Mikhlin type multiplier theorem is given, yielding boundedness for certain known operators . We also give $\ell^p-\ell^q$ boundedness of a discrete wave equation.