Francisco S. N. Lobo

Entropy dynamics in gravitational collapse: From Minkowski breaking to de Sitter thermodynamics

The origin of black hole entropy remains one of the deepest mysteries in modern physics. Two recent developments offer complementary perspectives on this puzzle: the entropy release from regular Schwarzschild black holes with a de Sitter core (the OCK construction), and the local...

Buchdahl solution generator for Einstein-sigma gravity and multiscalar-tensor gravity

Buchdahl transformations provide a geometric route from vacuum spacetimes to scalar-field solutions. We formulate this mechanism as a target-covariant solution generator for Einstein gravity coupled to nonlinear sigma models in $D>3$ dimensions. On any connected region in which a...