Alexandros Chapsiadis

Alexandros Chapsiadis (Greek: Δρ. Αλέξανδρος Χαψιάδης, 1946–1992) was a mathematician and physicist. He was born and raised in Alexandroupolis, Greece.

Chapsiadis graduated from the Department of Mathematics, Aristotle University of Thessaloniki, Greece, in 1973. In 1975 he received an MSc in Mathematics at the Imperial College London, UK. In 1980 he joined the Technological University of Kavala, Greece, as an assistant professor in Mathematics. In 1988 Chapsiadis received a PhD in Physics, from the Astrophysics Group, Department of Physics, Aristotle University of Thessaloniki, Greece.

In his doctoral Thesis, under the supervision of Prof. M. Michalodimitrakis, he studied the fundamental problem, in Mechanics, of a two–body system consisting of a solid body and a material point. He was the first to prove the existence of bounded motions for an isolated system, consisting of a solid body ${\displaystyle B_{1}}$ and a material point ${\displaystyle B_{2}}$, moving under their mutual gravitational attraction. Chapsiadis and Michalodimitrakis also found the necessary and sufficient condition for a configuration of the system to be compatible with the given values of the energy ${\displaystyle E}$ and the angular momentum vector ${\displaystyle {\hat {L}}}$ (or the ${\displaystyle L^{2}}$). They showed that this condition is also valid for a system of ${\displaystyle N\geq 2}$ solids. This fundamental result was published in the Celestial Mechanics Journal.