Dymnikova Black Hole Surrounded by Quintessence

TL;DR

This work extends the regular Dymnikova black hole by embedding it in a quintessence field described by a state parameter $\omega$ and normalization $c$. It analyzes thermodynamics, null geodesics and shadows, and scalar quasinormal modes to show how quintessence alters Hawking temperature, heat capacity, horizon structure, light deflection, and damping of perturbations. The results reveal parameter-dependent phase transitions via the Davies point, and demonstrate that shadows remain observationally consistent with current measurements (e.g., Sgr A$^*$) while QNMs exhibit enhanced damping, implying greater stability. Together, these findings provide a cohesive view of how quintessence influences the observational and dynamical properties of a regular black hole.

Abstract

The Dymnikova black hole (BH) is a regular solution that interpolates between a de Sitter core near the origin and a Schwarzschild-like behavior at large distances. In this work, we investigate the properties of a Dymnikova BH immersed in a quintessential field, characterized by the state parameter $ω$ and a normalization constant $c$. We explore the thermodynamic behavior, null geodesics, scalar quasinormal modes and shadow profiles for this model. Our analysis shows that the presence of quintessence alters the Hawking temperature and specific heat, leading to parameter-dependent phase transitions. The null geodesics and corresponding black hole shadows are also found to be sensitive to the model parameters, especially $ω$ and $c$. This sensitivity influences light deflection and shadow size. Furthermore, we compute the scalar quasinormal modes and observe that quintessence tends to enhance the damping of the modes, indicating greater stability under perturbations.

Figures (7)

• Figure 1: The function $f(r)$ is plotted for various sets of the parameters $c, r_0, r_g$ and $w$.
• Figure 2: The Hawking temperature $T$ is plotted for various sets of the parameters $c, r_0, r_g$ and $w$ as function of $r$.
• Figure 3: The thermal capacity $C$ is plotted for various sets of the parameters $c, r_0, r_g$ and $w$ as function of $r$.
• Figure 4: The effective Potential $V_{eff}$ of the black hole is plotted for various sets of the parameters $c$ and $w$ as function of $r$.
• Figure 5: Geodesics of massless particles near the Dymnikova black hole surrounded by quintessence. The purple lines indicates the particles that do not fall in the black hole, going therefore to cosmological horizon, while the red lines are for those particles that end up falling in the black hole. For this plot we have considered $M=1$ and $r_0=0.3$.