It is shown that all uniquely homogeneous spaces are connected. We characterize the uniquely homogeneous spaces that are semitopological or quasitopological groups. We identify two properties of homogeneous spaces called skew-2-flexibility and 2-flexibility that are useful in studying unique homogeneity. We also construct a large family of uniquely homogeneous spaces with only trivial continuou...

This note was written in 1997 after a talk I gave at the séminaire de complexité et cryptographie at the École Normale Supérieure After it was rejected at crypto97 I forgot it until a few colleagues of mine informed me that it could be of some interest to some researchers in the field of algorithmic and cryptography. Although I am not quite happy with the redaction of this note, I believe it is...

We derive Banach-Stone theorems for spaces of homogeneous polynomials. We show that every isometric isomorphism between the spaces of n-homogeneous approximable polynomials on real Banach spaces E and F is induced by an isometric isomorphism of E′ onto F ′. With an additional geometric condition we obtain the analogous result in the complex case. Isometries between spaces of n-homogeneous integ...

The group-invariant geometry on real and complex n-balls is hyperbolic geometry, if one pursues classical geometric notions in this context, in the sense that there are infinitely many straight lines (geodesics) through a given point not on a given straight line, thus contravening the parallel postulate for Euclidean geometry. We will not consider classical geometric notions here, since the tra...