The Robinson-Trautman spacetime and its holographic fluid

Understand

We discuss the holographic reconstruction of four-dimensional asymptotically anti-de Sitter Robinson-Trautman spacetime from boundary data.

• We use for that a resummed version of the derivative expansion.
• The latter involves a vector field, which is interpreted as the dual-holographic-fluid velocity field and is naturally defined in the Eckart frame.
• In this frame the analysis of the non-perfect holographic energy-momentum tensor is considerably simplified.