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In algebra, the Chevalley–Warning theorem implies that certain polynomial equations in sufficiently many variables over a finite field have solutions. It was proved by and a slightly weaker form of the theorem, known as Chevalley's theorem, was proved by . Chevalley's theorem implied Artin's and Dickson's conjecture that finite fields are quasi-algebraically closed fields . == Statement of the theorems == Let be a finite field and be a set of polynomials such that the number of variables satisfies : where is the total degree of . The theorems are statements about the solutions of the following system of polynomial equations : * ''Chevalley–Warning theorem'' states that the number of common solutions is divisible by the characteristic of . Or in other words, the cardinality of the vanishing set of is modulo . * ''Chevalley's theorem'' states that if the system has the trivial solution , i.e. if the polynomials have no constant terms, then the system also has a non-trivial solution . Chevalley's theorem is an immediate consequence of the Chevalley–Warning theorem since is at least 2. Both theorems are best possible in the sense that, given any , the list has total degree and only the trivial solution. Alternatively, using just one polynomial, we can take ''f''1 to be the degree ''n'' polynomial given by the norm of ''x''1''a''1 + ... + ''x''''n''''a''''n'' where the elements ''a'' form a basis of the finite field of order ''p''''n''. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Chevalley–Warning theorem」の詳細全文を読む スポンサード リンク
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