Tidal Love Numbers of Thin-Shell Wormholes, de Sitter Gravastars, and Anti-de Sitter Gravastars via Full Perturbed Junction Conditions

Abstract

In this work, we revisit the tidal Love numbers (TLNs) of several classes of exotic compact objects (ECOs) using the recently derived full perturbed junction conditions. We investigate four representative thin-shell models: wormholes, de Sitter gravastars with zero surface energy density, general de Sitter gravastars, and anti-de Sitter gravastars. Previous studies of wormholes and de Sitter gravastars with zero surface energy density, based on simplified matching conditions, suggested that the TLNs of ultracompact ECOs vanish logarithmically in the black-hole (BH) limit, leading to the conjecture that this logarithmic dependence is a generic feature of ultracompact exotic objects. We show that this logarithmic behavior is not universal once the full perturbed junction conditions are imposed. In particular, the odd-parity TLNs exhibit polynomial scaling in the BH limit for all the models considered, while the even-parity sector displays both logarithmic and polynomial behaviors depending on the model. We also find that the signs of the TLNs can differ qualitatively from previous results, especially in the odd-parity sector. Our results demonstrate that the tidal response of ECOs is strongly affected by the perturbed matching conditions and that the previously conjectured universal logarithmic scaling near the BH limit is not generic.