The semi-analytical model (based on the averaging technique) for long-term orbital evolution has proven to be useful in both astrophysical and astrodynamical contexts. In this secular approximation, orbits exhibit rich evolutionary behaviors under effects of various perturbations. For example, hierarchical three-body systems, Lidov-Kozai mechanism based quadrupole-level third-body perturbation ...

Integrated optics and silicon photonics is a rapidly maturing technology progressing in telecom, computation, sensing. Surface-roughness-induced scattering the primary source of optical loss most photonic integrated circuits, as such, ultimately limits performance their applications. However, closed-form description for arbitrary refractive index profiles remains lacking, even though such one e...