LECTURE NOTES IN ANALYSIS (2011)
《LECTURE NOTES IN ANALYSIS (2011)》 · 第 226 页 · Section 5.2「Simultaneous Linear Equations」后的说明
From the work of Hasse and Minkowski it is also known that a single quadratic form, in any number of variables, has a nontrivial solution in integers provided that it has nontrivial solutions everywhere locally. An interesting special case of this is the subject of the next section. Unfortunately, this "Hasse-Minkowski principle" does not hold in general.