When L/K is separable, the trace provides a duality theory via the trace form: the map from L × L to K sending (x, y) to TrL/K(xy) is a nondegenerate, symmetric, bilinear form called the trace form. An example of where this is used is in algebraic number theory in the theory of the different ideal.
The trace form for a finite degree field extension L/K has non-negative signature for any field ordering of K. The converse, that every Witt equivalence class with non-negative signature contains a trace form, is true for algebraic number fields K.
Read more about this topic: Field Trace
Famous quotes containing the words trace and/or form:
“‘Tis chastity, my brother, chastity.
She that has that is clad in complete steel,
And like a quivered nymph with arrows keen
May trace huge forests and unharbored heaths,
Infamous hills and sandy perilous wilds,
Where, through the sacred rays of chastity,
No savage fierce, bandit, or mountaineer
Will dare to soil her virgin purity.”
—John Milton (1608–1674)
“The worker can unionize, go out on strike; mothers are divided from each other in homes, tied to their children by compassionate bonds; our wildcat strikes have most often taken the form of physical or mental breakdown.”
—Adrienne Rich (b. 1929)