A mathematical analysis of the virial theorem can be found at http://astrosun.tn.cornell.edu/courses/astro201/vt.htm
... Syndrome[?] Asherman's syndrome[?] Aspartylglycosaminuria[?] Asperger syndrome Aspergillosis[?] Asphyxia neonatorum[?] Asthenia[?] Asthenophobia[?] ...