In quantum systems, a subspace spanned by degenerate eigenvectors of the Hamiltonian may have higher symmetries than those itself. When this enhanced-symmetry group can be generated from local operators, we call it quasisymmetry group. is Lie group, an external field coupled to certain generators lifts degeneracy, and results in exactly periodic dynamics within subspace, namely, many-body-scar ...

We study the chaotic signatures of geodesic dynamics a nonspinning test particle in effective-one-body (EOB) formalism for inspiral process spinning binary black holes. first show that second-order post-Newtonian (2PN) EOB is nonintegrable by demonstrating metric does not satisfy criterion existence Carter constant. then employ numerical to find plateaus rotation curve, which are associated wit...

Recent advances in optical Feshbach resonance technique have enabled the experimental investigation of atomic gases with time-dependent interaction. In this work, we study many-body dynamics weakly interacting bosons subject an arbitrary time varying scattering length. By employing a variational ansatz, derive effective Hamiltonian that governs thermal particles. Crucially, show there exists hi...