On reduced positive definite ternary quadratic forms. (Q2585804)

From MaRDI portal





scientific article
Language Label Description Also known as
English
On reduced positive definite ternary quadratic forms.
scientific article

    Statements

    On reduced positive definite ternary quadratic forms. (English)
    0 references
    1940
    0 references
    Die positiv definite reelle ternäre quadratische Form \[ f (x) = a_1x_1^2 +a_2x_2^2 +a_3x_3^2+2b_1x_2x_3+2b_2x_1x_3+2b_3x_1x_2 \] heißt reduziert, wenn die Ungleichungen \(0<a_1\leqq a_2\leqq a_3, 0\leqq b_1\leqq \tfrac12a_2,\) \(|b_2|\leqq \tfrac12a_1, 0\leqq b_3\leqq\tfrac12a_1,\) \(b_1-b_2+b_3\leqq \tfrac12(a_1+a_2)\) gelten. Neuer Beweis für die Abschätzung \(a_1a_2a_3\leqq 2D\), wo \(D = a_1a_2a_3-(a_1b^2_1 + a_2b_2^2 +a_3b_3^2 - 2b_1b_2b_3)\) die Determinante von \(f(x)\) ist.
    0 references
    0 references

    Identifiers