Publikace ÚTF

In this paper we calculate the Bondi mass of asymptotically flat spacetimes
with interacting electromagnetic and scalar fields. The system of coupled Einstein–
Maxwell–Klein–Gordon equations is investigated and corresponding field equations
are written in the spinor form and in the Newman–Penrose formalism. Asymptotically
flat solution of the resulting system is found near null infinity. Finally we use the
asymptotic twistor equation to find the Bondi mass of the spacetime and derive the
Bondi mass-loss formula.We compare the results with our previous work (Bičák et al.
in Class Quantum Gravity 27(17):175011, 2010) and show that, unlike the conformal
scalar field, the (Maxwell–)Klein–Gordon field has negatively semi-definite mass-loss
formula.