Gravitational Memory and Compact Extra Dimensions

Understand

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.