arXiv subjects

Witold Rosicki

Publications and source records attributed to Witold Rosicki.

4 recordsLinked to original sources

arXiv2013

Cocycle invariants of codimension 2-embeddings of manifolds

We consider the classical problem of a position of n-dimensional manifold M in R^{n+2}. We show that we can define the fundamental (n+1)-cycle and the shadow fundamental (n+2)-cycle for a fundamental quandle of a knotting M to R^{n+2}. In particular, we show that for any fixed quandle, quandle coloring, and shadow quandle coloring, of a diagram of M embedded in R^{n+2} we have (n+1)- and (n+2)-(co)cycle invariants (i.e. invariant under Roseman moves). We speculate on a similar construction for general Yang-Baxter operators.

math.GT↗

arXiv2012

On Minc's sheltered middle path

This paper shows that a construction, which was introduced by Piotr Minc in connection with a problem that came from Helly type theorems and that allows to replace three PL-arcs with a "sheltered middle path", can in the case of general (non-PL) paths result in the topologist's sine curve.

math.GT↗

arXiv2008

Embeddability of multiple cones

The main result of this paper is that if $X$ is a Peano continuum such that its $n$-th cone $C^n(X)$ embeds into $\RR^{n+2}$ then $X$ embeds into $S^2$. This solves a problem proposed by W. Rosicki.

math.GT↗

arXiv2004

The topological interpretation of the core group of a surface in S^4

We give a topological interpretation of the core group invariant of a surface embedded in S^4. We show that the group is isomorphic to the free product of the fundamental group of the double branch cover of S^4 with the surface as a branched set, and the infinite cyclic group. We present a generalization for unoriented surfaces, for other cyclic branched covers, and other codimension two embeddings of manifolds in spheres. The method of computing the fundamental group of n-fold cyclic branched covers is related to the one described in R.H.Crowell, The derived group of a permutation representation, Adv. in Math. 53(1), 1984, 99--124. We use these computations in recent papers: http://front.math.ucdavis.edu/math.GT/0302098 http://front.math.ucdavis.edu/math.GT/0309140

math.GT↗