Shadow and Thermodynamics of deformed Schwarzschild-AdS black hole with a Cloud of Strings embedded in Perfect Fluid Dark Matter

TL;DR

This paper explores how a deformed Schwarzschild-AdS black hole's optical and thermodynamic properties are influenced by a cloud of strings and perfect fluid dark matter, revealing that critical behavior resembles that of RN-AdS black holes.

Contribution

It provides a comprehensive analysis of the optical shadow and thermodynamics of a deformed Schwarzschild-AdS black hole with matter fields, showing no new phase transitions arise from deformation or dark matter.

Findings

Photon sphere and shadow are affected by matter and deformation.

Thermodynamic analysis shows no new phase transitions from deformation or dark matter.

Critical behavior is similar to Reissner-Nordström-AdS black holes.

Abstract

We investigate the optical and thermodynamic properties of a deformed Schwarzschild Anti-de Sitter (AdS) black hole coupled to a cloud of strings and embedded in perfect fluid dark matter. We analyze the photon sphere and the corresponding black hole shadow, determining how these observables are affected by the string cloud, dark matter distribution, and geometric deformation. The thermodynamic behavior is studied through both the quasi-homogeneous fundamental equation within the classical physical approach and the geometric framework of geometrothermodynamics (GTD), showing full consistency between the two descriptions. In the extended phase space, we examine the critical structure and phase behavior of the system. Our analysis reveals that neither the geometric deformation nor the dark matter parameter generates new phase transitions; criticality emerges only in the vicinity of the Reissner--Nordstr\"om--AdS solution (RN--AdS), where the deformation parameter effectively plays the role of an electric charge squared. These results clarify the interplay between matter distributions, geometric deformations, and the phase structure of AdS black holes.