Non-Schwarzschild black holes sourced by scalar-vector fields

Abstract

In a scalar-vector-gravity theory with the vector sector described by nonlinear electrodynamics, the field equations are integrated using the well-known gravitational decoupling method. The resulting spacetime corresponds to a spherically symmetric and static non-Schwarzschild black hole. Employing the master equations for both even and odd parity modes, it is proven that the solution is stable under certain conditions satisfied by the scalar and vector field parameters. To further corroborate the theoretical feasibility of this toy model, the causal structure, geodesic motion for massive particles, and some thermodynamic features are analyzed in detail.

Figures (8)

• Figure 1: The inverse radial metric potential versus the radial coordinate for $M=1$, $b=3$, $c=-2$, $l=-1$ and $\alpha=0.2$.
• Figure 2: Parameter-space structure of the minimally deformed solution in the $(b,l\alpha)$ plane for the representative case $M=1$ and $c=-2$. The solid curve $l\alpha_{\rm crit}(b)=-(4-b)^2$ separates the single–horizon branch (blue) from the multi–horizon branch (red). The dashed horizontal line $l\alpha=0$ corresponds to the Schwarzschild limit where the deformation vanishes, while the gray region above it corresponds to $l\alpha>0$, which lies outside the branch considered in the present analysis. The vertical dashed lines indicate the interval $2<b<4$ required for the regular behavior of the deformation.
• Figure 3: Odd parity condition for stability for $M=1$, $b=3$, $c=-2$, $l=-1$ and $\alpha=0.2$.
• Figure 4: Even parity condition for stability for $M=1$, $b=3$, $c=-2$, $l=-1$ and $\alpha=0.2$.
• Figure 5: Radial The effective potential versus the radial coordinate for $M=1$, $b=3$, $c=-2$, $\alpha=0.2$ and $l=-1$.