Search results
Results From The WOW.Com Content Network
A mapping q : M → R : v ↦ b(v, v) is the associated quadratic form of b, and B : M × M → R : (u, v) ↦ q(u + v) − q(u) − q(v) is the polar form of q. A quadratic form q : M → R may be characterized in the following equivalent ways: There exists an R-bilinear form b : M × M → R such that q(v) is the associated quadratic form.
The mass formula is often given for integral quadratic forms, though it can be generalized to quadratic forms over any algebraic number field. In 0 and 1 dimensions the mass formula is trivial, in 2 dimensions it is essentially equivalent to Dirichlet's class number formulas for imaginary quadratic fields , and in 3 dimensions some partial ...
A quadratic form (not quadratic equation) is any polynomial in which each term has variables appearing exactly twice. The general form of such an equation is ax 2 + bxy + cy 2. (All coefficients must be whole numbers.) A given quadratic form is said to represent a natural number if substituting specific numbers for the variables gives the ...
Quadratic forms correspond one-to-one to symmetric bilinear forms over the same space. [2] A symmetric bilinear form is also described as definite, semidefinite, etc. according to its associated quadratic form. A quadratic form Q and its associated symmetric bilinear form B are related by the following equations:
Otherwise it is a definite quadratic form. More explicitly, if q is a quadratic form on a vector space V over F, then a non-zero vector v in V is said to be isotropic if q(v) = 0. A quadratic form is isotropic if and only if there exists a non-zero isotropic vector (or null vector) for that quadratic form.
Weight 3: The only Siegel modular form is 0. Weight 4: For any degree, the space of forms of weight 4 is 1-dimensional, spanned by the theta function of the E 8 lattice (of appropriate degree). The only cusp form is 0. Weight 5: The only Siegel modular form is 0. Weight 6: The space of forms of weight 6 has dimension 1 if the degree is at most ...
The Hasse–Minkowski theorem reduces the problem of classifying quadratic forms over a number field K up to equivalence to the set of analogous but much simpler questions over local fields. Basic invariants of a nonsingular quadratic form are its dimension , which is a positive integer, and its discriminant modulo the squares in K , which is ...
Pages in category "Quadratic forms" The following 61 pages are in this category, out of 61 total. This list may not reflect recent changes. ...