The off-shell 4D/5D connection

Understand

A systematic off-shell reduction scheme from five to four space-time dimensions is presented for supergravity theories with eight supercharges.

• It is applicable to theories with higher-derivative couplings and it is used to address a number of open questions regarding BPS black holes in five dimensions.
• Under this reduction the 5D Weyl multiplet becomes reducible and decomposes into the 4D Weyl multiplet and an extra Kaluza-Klein vector multiplet.
• The emergence of the pseudoscalar field of the latter multiplet and the emergence of the 4D R-symmetry group are subtle features of the reduction.