| 释义 |
Quadratic FieldAn Algebraic Integer of the form where is Squarefree forms a quadratic field and is denoted . If , the field is called a Real Quadratic Field, and if , it is called anImaginary Quadratic Field. The integers in are simply called ``the''Integers. The integers in are called Gaussian Integers, and the integers in are called Eisenstein Integers. TheAlgebraic Integers in an arbitrary quadratic field do not necessarily have unique factorizations.For example, the fields and are not uniquely factorable, since
 | (1) |
 | (2) |
although the above factors are all primes within these fields. All other quadratic fields with are uniquely factorable.
Quadratic fields obey the identities
 | (3) |
 | (4) |
and
 | (5) |
The Integers in the real field are of theform , where
 | (6) |
There exist 22 quadratic fields in which there is a Euclidean Algorithm (Inkeri 1947). See also Algebraic Integer, Eisenstein Integer, Gaussian Integer, Imaginary Quadratic Field,Integer, Number Field, Real Quadratic Field References
Shanks, D. Solved and Unsolved Problems in Number Theory, 4th ed. New York: Chelsea, pp. 153-154, 1993. |