2020/10/31 by Masato Nozawa · 1 citation
Mathematics · Physics and Astronomy · #Advanced Differential Geometry Research #Black Holes and Theoretical Physics #Cosmological constant #Cosmology and Gravitation Theories #Curvature #Dilaton #General relativity #Geometry #Mathematical physics #Mathematics #Physics #Quantum mechanics #Scalar (mathematics) #Scalar curvature #Scalar field #Spacetime #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.103.024004
published as Phys. Rev. D 103, 024004 (2021) · 2 figures, 1 table, 33 pages; v2: refs added, to appear in PRD
openalex created_date 2020/10/22 · arxiv created 2021/01/05 · openalex publication_date 2021/01/06 · arxiv updated 2021/01/13 · openalex updated_date 2026/08/05
We present a method to generate static solutions in the Einstein-Maxwell system with a (phantom) dilaton field in n(\ensuremath≥4) dimensions, based upon the symmetry of the target space for the nonlinear sigma model. Unlike the conventional Einstein-Maxwell-dilaton system, there appears a critical value of the coupling constant for a phantom dilaton field. In the noncritical case, the target space is ℝ\ifmmode×\else\texttimes\fiSL(2,ℝ)/H with the maximal subgroup H=SO(2),SO(1,1), whereas in the critical case the target space becomes a symmetric pp-wave and the corresponding Killing vectors form a non-semi-simple algebra. In either case, we apply the formalism to charge up the neutral solutions and show the analytical expression for dilatonic charged versions of (i) the Fisher solution, (ii) the Gibbons solution, and (iii) the Ellis-Bronnikov solution. We discuss global structures of these solutions in detail. It turns out that some solutions contained in the Fisher and Gibbons classes possess the parallelly propagated (p.p) curvature singularities in the parameter region where all the scalar curvature invariants remain bounded. These p.p curvature singularities are not veiled by a horizon, thrusting them into physically untenable nakedly singular spacetimes. We also demonstrate that the dilatonic-charged Ellis-Bronnikov solution admits a parameter range under which the solution represents a regular wormhole spacetime in the two-sided asymptotically flat regions.