Page 1 Next

Displaying 1 – 20 of 39

Showing per page

Generalized analytic spaces, completeness and fragmentability

Petr Holický (2001)

Czechoslovak Mathematical Journal

Classical analytic spaces can be characterized as projections of Polish spaces. We prove analogous results for three classes of generalized analytic spaces that were introduced by Z. Frolík, D. Fremlin and R. Hansell. We use the technique of complete sequences of covers. We explain also some relations of analyticity to certain fragmentability properties of topological spaces endowed with an additional metric.

Generalized n-colorings of links

Daniel Silver, Susan Williams (1998)

Banach Center Publications

The notion of an (n,r)-coloring for a link diagram generalizes the idea of an n-coloring introduced by R. H. Fox. For any positive integer n the various (n,r)-colorings of a diagram for an oriented link l correspond in a natural way to the periodic points of the representation shift Φ / n ( l ) of the link. The number of (n,r)-colorings of a diagram for a satellite knot is determined by the colorings of its pattern and companion knots together with the winding number.

Generalized projections of Borel and analytic sets

Marek Balcerzak (1996)

Colloquium Mathematicae

For a σ-ideal I of sets in a Polish space X and for A ⊆ X 2 , we consider the generalized projection (A) of A given by (A) = x ∈ X: Ax ∉ I, where A x =y ∈ X: 〈x,y〉∈ A. We study the behaviour of with respect to Borel and analytic sets in the case when I is a 2 0 -supported σ-ideal. In particular, we give an alternative proof of the recent result of Kechris showing that [ 1 1 ( X 2 ) ] = 1 1 ( X ) for a wide class of 2 0 -supported σ-ideals.

Currently displaying 1 – 20 of 39

Page 1 Next