Dr. Chiranjib Singha

In this talk, I will first discuss the tidal response of rotating BTZ black holes to scalar perturbations, showing that the real part of the response function is non-zero and therefore leads to finite tidal Love numbers (TLNs). The response also exhibits scale-dependent logarithmic running. Extremal rotating BTZ black holes show qualitatively similar behaviour, and I will outline a procedure to compute the tidal response for charged rotating BTZ spacetimes as well. Motivated by the vanishing static TLNs of four-dimensional vacuum black holes in general relativity, I will then explore tidal deformation in higher-curvature gravity theories. In pure Lovelock gravity, static TLNs vanish in certain cases, extending the four-dimensional result to specific higher-dimensional scenarios. In contrast, black holes in Einstein–Gauss–Bonnet gravity generally possess non-zero TLNs, whose magnitude depends on the Gauss–Bonnet coupling. These results emphasize the strong dependence of black hole tidal response on both spacetime dimensionality and the underlying theory of gravity. ArXiv link: https://arxiv.org/abs/2407.09470 , https://arxiv.org/abs/2508.14944