Representations of Binary Forms by Certain Quinary Positive Integral Quadratic Forms, Original Research Article

In this article, we provide the complete answer to a question raised by Kitaoka in his book. (1999, “Arithmetic of Quadratic Forms,” Cambridge Univ. Press, Cambridge, UK). More precisely, we prove that A4perpendicularleft angle bracket4right-pointing angle bracket represents all but one and D420[2 image] represents all but three binary positive even image-lattices. We further investigate representations of the binary forms by quinary forms in certain positive even 2-universal genera of class number 2.