Gravitational Memory and Compact Extra Dimensions
  We develop a general formalism for treating radiative degrees of freedom near
$\mathscr{I}^{+}$ in theories with an arbitrary Ricci-flat internal space.
These radiative modes are encoded in a generalized news tensor which decomposes
into gravitational, electromagnetic, and scalar components. We find a preferred
gauge which simplifies the asymptotic analysis of the full nonlinear Einstein
equations and makes the asymptotic symmetry group transparent. This asymptotic
symmetry group extends the BMS group to include angle-dependent isometries of
the internal space. We apply this formalism to study memory effects, which are
expected to be observed in future experiments, that arise from bursts of
higher-dimensional gravitational radiation. We outline how measurements made by
gravitational wave observatories might probe properties of the compact extra
dimensions.
