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 ...

Using the Keeton and Petters approach, we determine the deflection angle. We also investigate the motion of photons around a parameterized black hole in the presence of non-magnetized cold plasma 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 ...

Abstract: Traditional liquid prisms face challenges in achieving large aperture and wide deflection angle. In this letter, a large aperture liquid prism with mechanical drive is proposed. Four baffle ...

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 ...