Consistency conditions and the derivation of harmonic structure in Einstein-Maxwell-dilaton theory
- 1University of Saskatchewan
- 2Red Deer Polytechnic
Abstract
Many exact solutions of Einstein–Maxwell and Einstein–Maxwell-dilaton theory share a common structural pattern in which the metric functions are built from harmonic functions on a specified spatial base, often taken to be flat. We investigate this pattern by considering the Einstein–Maxwell-dilaton theory in arbitrary dimensions, where the dilaton field is non-trivially coupled to the Maxwell field and to a Liouville-type potential proportional to the cosmological parameter. Without imposing either the base geometry or the harmonic form of the metric function in advance, we show that for the generic branch, the field equations force the dilaton couplings to be equal, restrict the spatial base geometry to be Ricci flat, and make the metric function harmonic on this base. The resulting spacetime can then be written in terms of a conformal potential. We also consider a purely spatial branch, which instead leads to a distinct constraint on the coupling constants. These results provide a unified field-equation derivation of the harmonic behavior and conformal structure that appear in several classes of solutions, including multi-center geometries, cosmological solutions, and dynamical black holes.
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BibTeX
@article{fahim2026consistency,
title = {{Consistency conditions and the derivation of harmonic structure in Einstein-Maxwell-dilaton theory}},
author = {Bardia H. Fahim and Joshua G. Fenwick},
journal = {The European Physical Journal C},
year = {2026},
month = oct,
doi = {10.1140/epjc/s10052-026-16426-0},
url = {https://link.springer.com/10.1140/epjc/s10052-026-16426-0},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Consistency conditions and the derivation of harmonic structure in Einstein-Maxwell-dilaton theory
AU - Bardia H. Fahim
AU - Joshua G. Fenwick
PY - 2026
DA - 2026/10/08
JO - The European Physical Journal C
DO - 10.1140/epjc/s10052-026-16426-0
UR - https://link.springer.com/10.1140/epjc/s10052-026-16426-0
AB - Many exact solutions of Einstein–Maxwell and Einstein–Maxwell-dilaton theory share a common structural pattern in which the metric functions are built from harmonic functions on a specified spatial base, often taken to be flat. We investigate this pattern by considering the Einstein–Maxwell-dilaton theory in arbitrary dimensions, where the dilaton field is non-trivially coupled to the Maxwell field and to a Liouville-type potential proportional to the cosmological parameter. Without imposing either the base geometry or the harmonic form of the metric function in advance, we show that for the generic branch, the field equations force the dilaton couplings to be equal, restrict the spatial base geometry to be Ricci flat, and make the metric function harmonic on this base. The resulting spacetime can then be written in terms of a conformal potential. We also consider a purely spatial branch, which instead leads to a distinct constraint on the coupling constants. These results provide a unified field-equation derivation of the harmonic behavior and conformal structure that appear in several classes of solutions, including multi-center geometries, cosmological solutions, and dynamical black holes.
SN - 1434-6044
SN - 1434-6052
ER -