Explorations in 2+1 AdS Pure Gravity: Path Integral Formulation and Partition Function Analyses in BTZ Mini-Superspace

Abstract: In this work, we employ the Hamiltonian approach to analyze the Lorentzian path integral in 2+1 AdS gravity, with an aim to sum over all possible geometries, including naked singularities and BTZ black holes, between fixed initial and final surfaces. A novel path integral measure, grounded on the metric over mini-superspace, is proposed for executing the path integral. Shifting to Euclidean geometries, we derive the temperature and angular potential of Euclidean naked singularities within the partition function. Significantly, without utilizing conformal field theory, we extract logarithmic corrections to the entropy of BTZ black holes and compute the entropy of naked singularities, along with their log corrections.