2012/11/13 by Masatoshi Suzuki, Suzuki, Masatoshi
Mathematics · #30C15 #34A55 #34L40 #Classical Analysis and ODEs (math.CA) #FOS: Mathematics #Functional Analysis (math.FA) #Number Theory (math.NT) #math.CA #math.FA #math.NT #msc:30C15 #msc:34A55 #msc:34L40
paper · pdf · doi:10.48550/arxiv.1211.2953
28 pages; v2 29 pages, revision of Sec.8, typos corrected, refs. added
arxiv created 2012/12/14 · arxiv updated 2012/12/18
We establish a necessary and sufficient condition for all zeros of a self-reciprocal polynomial to lie on the unit circle. Moreover, we relate the necessary and sufficient condition with a canonical system of linear differential equations (in the sense of de Branges). This relationship enable us to understand that the property of a self-reciprocal polynomial having only zeros on the unit circle is equivalent to the positive semidefiniteness of Hamiltonians of corresponding canonical systems.