M ay 2 00 5 Transverse doubled knots and clasp disks

2 9 M ay 2 00 3 Property P for Knots admitting Certain Gabai Disks Oliver

We show that if a knot has a minimal spanning surface that admits certain Gabai disks, then this knot has Property P. As one of the applications we extend and simplify a recent result of Menasco and Zhang that closed 3-braid knots have Property P. Other applications are given.

. G T / 0 50 52 33 v 1 1 2 M ay 2 00 5 NEW TOPOLOGICALLY SLICE KNOTS

In the early 1980’s Mike Freedman showed that all knots with trivial Alexander polynomial are topologically slice (with fundamental group Z). This paper contains the first new examples of topologically slice knots. In fact, we give a sufficient homological condition under which a knot is slice with fundamental group Z⋉Z[1/2]. These two fundamental groups are known to be the only solvable ribbon...

ar X iv : 0 70 5 . 32 58 v 1 [ as tr o - ph ] 2 2 M ay 2 00 7 Disks around Young Binary Stars

ar X iv : 0 70 5 . 13 21 v 1 [ m at h . G T ] 9 M ay 2 00 7 Mutant knots with symmetry

Mutant knots, in the sense of Conway, are known to share the same Homfly polynomial. Their 2-string satellites also share the same Homfly polynomial, but in general their m-string satellites can have different Homfly polynomials for m > 2. We show that, under conditions of extra symmetry on the constituent 2-tangles, the directed m-string satellites of mutants share the same Homfly polynomial f...

ar X iv : a st ro - p h / 02 07 44 7 v 3 6 M ay 2 00 3 Application of MHD Disk Wind Solutions to Planetary / Protoplanetary Nebulae

Winds from accretion disks have been proposed as the driving source for precessing jets and extreme bipolar morphologies in Planetary Nebulae (PNe) and proto-PNe (pPNe). In this paper we address the applicability MHD disk wind models to PNe and pPNe. We first review Pelletier & Pudritz's (1992) non self-similar approach to magneto-centrifugal disk winds. We then discuss conditions which may occ...