We derive a coordinate-invariant expression for the photon deflection angle in the strong deflection limit (SDL) of stationary axisymmetric spacetimes. The key logarithmic-divergence coefficient is ...

The light bending (global and topological) phenomenon in the presence of black holes (BHs) will be examined by using the Gauss–Bonnet theorem (GBT) to understand the intricate physics. BHs inspired by ...

Abstract: In this paper, a composite anti-disturbance control method is proposed for electromechanical fin actuators with deflection angle constraints and multiple disturbances. Firstly, a ...

In oscillatory tests the measuring system moves backwards and forwards at a set frequency and amplitude. The advantage of performing the test in such a way is that small strains are applied onto the ...