A universal ribbon surface in $B^{4}$

A Universal Ribbon Surface in B

We construct an orientable ribbon surface F ⊂ B, which is universal in the following sense: any orientable 4-manifold M ∼= B ∪ 1-handles ∪ 2-handles can be represented as a cover of B branched over F .

Skeleton of a Multi-ribbon Surface

In this paper, two-dimensional manifolds in threedimensional Euclidian space are considered in order to single out surfaces whose skeletons fulfill the grass-fire concept. Among such surfaces we distinguish those ones that can be covered by finite number of adjacent patches. We name them multi-ribbon surfaces. We aim to calculate a multi-ribbon surface skeleton by constructing every patch Voron...

On the universal sl2 invariant of ribbon bottom tangles

A bottom tangle is a tangle in a cube consisting of arc components whose boundary points are on a line in the bottom square of the cube. A ribbon bottom tangle is a bottom tangle whose closure is a ribbon link. For every n-component ribbon bottom tangle T , we prove that the universal invariant JT of T associated to the quantized enveloping algebra Uh(sl2) of the Lie algebra sl2 is contained in...

A Universal Newborn Hearing Screening in Iran

Objectives: In September 2002 University of Social Welfare & Rehabilitation Sciences established a pilot universal newborn hearing screening program in two crowded maternity hospital in Tehran. Our objective was to assess the feasibility of implementing universal newborn hearing screening in IRAN. Methods: Between September 2002 and March 2004 a total of 7718 newborns were screened for heari...

Mani and shapur a universal faith for e universal kingdom