Higher-order intersections in low-dimensional topology

Higher-order intersections in low-dimensional topology.

We show how to measure the failure of the Whitney move in dimension 4 by constructing higher-order intersection invariants of Whitney towers built from iterated Whitney disks on immersed surfaces in 4-manifolds. For Whitney towers on immersed disks in the 4-ball, we identify some of these new invariants with previously known link invariants such as Milnor, Sato-Levine, and Arf invariants. We al...

Topology and higher dimensional representations

SU(3) gauge theory in the 2-index symmetric (sextet) and fundamental representations is considered in symmetric and periodic boxes. Using the overlap formulation in the quenched approximation it is shown that the topological charge obtained from the sextet index theorem always leads to an integer value and agrees with the charge obtained from the fundamental index theorem in the continuum. At l...

Problems in Low-dimensional Topology

Four-dimensional topology is in an unsettled state: a great deal is known, but the largest-scale patterns and basic unifying themes are not yet clear. Kirby has recently completed a massive review of low-dimensional problems [Kirby], and many of the results assembled there are complicated and incomplete. In this paper the focus is on a shorter list of \tool" questions, whose solution could unif...

Low - dimensional Topology 57

Intersections of Golay codes with higher order Kerdock codes

Golay codewords are useful for transmission schemes such as OFDM, and [MacWilliams/Sloane] demonstrated that these codewords are bent functions contained in second order Reed-Muller codes. This paper investigates the intersection between these codes and Kerdock-like codes.