Quasi-algebraically Closed Field

Quasi-algebraically Closed Field

In mathematics, a field F is called quasi-algebraically closed (or C1) if every non-constant homogeneous polynomial P over F has a non-trivial zero provided the number of its variables is more than its degree. The idea of quasi-algebraically closed fields was investigated by C. C. Tsen, a student of Emmy Noether in a 1936 paper; and later in the 1951 Princeton University dissertation of Serge Lang. The idea itself is attributed to Lang's advisor Emil Artin.

Formally, if P is a non-constant homogeneous polynomial in variables

X1, ..., XN,

and of degree d satisfying

d < N

then it has a non-trivial zero over F; that is, for some xi in F, not all 0, we have

P(x1, ..., xN) = 0.

In geometric language, the hypersurface defined by P, in projective space of dimension N − 1, then has a point over F.

Read more about Quasi-algebraically Closed Field:  Examples, Properties, Ck Fields

Famous quotes containing the words closed and/or field:

    Pray but one prayer for me ‘twixt thy closed lips,
    Think but one thought of me up in the stars.
    William Morris (1834–1896)

    But the old world was restored and we returned
    To the dreary field and workshop, and the immemorial feud

    Of rich and poor. Our victory was our defeat.
    Sir Herbert Read (1893–1968)