Black hole topologies and geodesic structures in symmetric teleparallel f(Q) gravity

Abstract

In this work, we investigate black hole solutions in the context of symmetric teleparallel gravity, specifically within f ( Q ) theory, where Q denotes the non-metricity scalar. We focus on static, circularly symmetric spacetimes in ( 2 + 1 ) -dimensions, analyzing both charged and uncharged cases. By adopting a power-law form for f ( Q ) , we derive exact black hole solutions and explore their thermodynamic and geometric properties. Curvature and non-metricity scalars reveal central singularities stronger than those in general relativity. We find that the horizon radii increase with the charge parameter while higher values of the non-metricity coefficient, c 4 , or the cosmological constant Λ tend to merge or eliminate horizons, reducing their total number and altering the near-origin structure of the spacetime. We perform a detailed topological analysis based on the Euler characteristic and examine the geodesic completeness of the spacetime. Our findings show that, depending on the presence of electric charge, the singularity may or may not be reachable by geodesics. The thermodynamic stability is confirmed via temperature, entropy, and heat capacity calculations. This study highlights the rich structure of f ( Q ) gravity in lower-dimensional settings and offers new insights into the nature of singularities and black hole topologies in modified gravity theories.