Minimal Extensions of Algebraic Groups and Linear Independence

Algebraic extensions in free groups

The aim of this paper is to unify the points of view of three recent and independent papers (Ventura 1997, Margolis, Sapir and Weil 2001 and Kapovich and Miasnikov 2002), where similar modern versions of a 1951 theorem of Takahasi were given. We develop a theory of algebraic extensions for free groups, highlighting the analogies and differences with respect to the corresponding classical field-...

Criteria for irrationality, linear independence, transcendence and algebraic independence

For proving linear independence of real numbers, Hermite [6] considered simultaneous approximation to these numbers by algebraic numbers. The point of view introduced by Siegel in 1929 [14] is dual (duality in the sense of convex bodies): he considers simultaneous approximation by means of independent linear forms. We define the height of a linear form L = a0X0 + · · · + amXm with complex coeff...

FINITE EXTENSIONS OF MINIMAL TRANSFORMATION GROUPS ( i )

In this paper we shall study homomorphisms p: W — Y on minimal transformation groups. We shall prove, in the case that W and Y are metrizable, that W is a finite (iV-to-1) extension of Y if and only if W is an Nfold covering space of Y and pisa covering map. This result places no further restrictions on the acting group. We shall then use this characterization to investigate the question of lif...

Linear Algebraic Groups

Linear Algebraic Groups