Probing Modified Gravity Theories with Scalar Fields Using Black-Hole Images

• DOI: 10.3390/universe9030147
• Publication Date: 2023-03-13T07:03:57Z
• Authors: Georgios Antoniou; Alexandros Papage...; Panagiota Kanti
• Keywords: Black hole (networking)

We study a number of well-motivated theories modified gravity with the common overarching theme that they predict existence compact objects, such as black holes and wormholes endowed scalar hair. compute shadow radius resulting objects demonstrate hole images, M87* or more recent SgrA* by Event Horizon Telescope (EHT) collaboration, could provide powerful way to constrain deviations metric functions from what is expected general relativity (GR) solutions. focus our attention on Einstein-scalar-Gauss–Bonnet (EsGB) theory three couplings, including dilatonic Z2 symmetric cases. then analyze in context spontaneous scalarization scenario within EsGB an additional coupling Ricci (EsRGB). Finally, we turn Einstein–Maxwell-Scalar (EMS) impact parameters shadow. Our results show imaging important tool for constraining hair, and, some part parameter space, solutions hair may be marginally favored compared GR.