The singular support of an $\mathrm{\ell }$-adic sheaf

We define the singular support of an $\mathrm{\ell }$-adic sheaf on a smooth variety over any field. To do this, we combine Beilinson’s construction of the singular support for torsion étale sheaves with Hansen and Scholze’s theory of universal local acyclicity for $\mathrm{\ell }$-adic sheaves.