title: Stratified Approximation Results in Singular Spaces creator: Listiyanto, - subject: ddc-500 subject: 500 Natural sciences and mathematics subject: ddc-510 subject: 510 Mathematics description: Determining conditions under which a given map is close to a homeomorphism has been an important problem in geometric topology. One of the major results related to the problem is the α-Approximation Theorem of Chapman and Ferry, which asserts that a small homotopy equivalence between manifolds is small homotopic to a homeomorphism. In this context, the smallness condition on a homotopy means that the size of the track covered by each point during the homotopy is small when measured by an open cover of the target space. In proving such a theorem, besides the original approach of ChapmanFerry which uses some results from topological surgery theory, there is another more geometric approach that is more suitable to establish a similar theorem for classes of spaces more general than manifolds. This second approach, due to Chapman himself, is to use controlled topological engulfing to prove a geometric result on approximate fibrations called the Sucking Principle. The α-Approximation Theorem then follows from an application of this principle together with the Cell-Like Approximation Theorem of Siebenmann. In this thesis, based on previous work of B. Hughes, we develop various tools that address the above approximation questions in a stratified setting of possibly singular spaces. In particular, we establish the Stratified Radial Engulfing Theorem, the Stratified Wrapping Up Theorem, the Stratified Handle Theorem, and the Stratified gamma-Sucking Theorem. As a consequence we obtain a Stratified Sucking Theorem with unstratified polyhedral target space. date: 2021 type: Dissertation type: info:eu-repo/semantics/doctoralThesis type: NonPeerReviewed format: application/pdf identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/29887/1/Dissertation_Listiyanto.pdf identifier: DOI:10.11588/heidok.00029887 identifier: urn:nbn:de:bsz:16-heidok-298874 identifier: Listiyanto, - (2021) Stratified Approximation Results in Singular Spaces. [Dissertation] relation: https://archiv.ub.uni-heidelberg.de/volltextserver/29887/ rights: info:eu-repo/semantics/openAccess rights: Please see front page of the work (Sorry, Dublin Core plugin does not recognise license id) language: eng