### Impacto

Gamboa Mutuberria, José Manuel
(1987)
*Some New Results On Ordered Fields.*
Journal Of Algebra, 110
(1).
pp. 1-12.
ISSN 0021-8693

Official URL: http://www.sciencedirect.com/science/journal/00218693

## Abstract

The author shows there is a non-Archimedean ordering of the field R(x, y), where x and y are algebraically independent over K, for which the identity is the only order-preserving automorphism.

The author proves the partly known result that the following statements about an ordered field K are equivalent: (1) each polynomial in K[x] satisfies the intermediate value theorem; (2) if f 2 K[x] and a < b, then f takes on its maximum value at some c 2 [a, b]; (3) K is real closed.

A (not necessarily ordered) field K is said to have the extension property if each automorphism of K(x), where x is transcendental over K, is an extension of an automorphism of K.

The author gives sufficient conditions for a field to have the the extension property. For example, a field has the extension property if, for some fixed integer n greater than two, each polynomial xn−ax−1, a 2 K, has a root in K.

Item Type: | Article |
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Uncontrolled Keywords: | real closed fields; automorphism of rational function field; non- archimedean ordered field; EP fields |

Subjects: | Sciences > Mathematics > Topology |

ID Code: | 15466 |

Deposited On: | 01 Jun 2012 10:52 |

Last Modified: | 01 Jun 2012 10:52 |

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