{ "id": "math/0305402", "version": "v3", "published": "2003-05-28T15:33:38.000Z", "updated": "2004-10-27T20:35:46.000Z", "title": "Eta invariants as sliceness obstructions and their relation to Casson-Gordon invariants", "authors": [ "Stefan Friedl" ], "comment": "Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol4/agt-4-39.abs.html", "journal": "Algebr. Geom. Topol. 4 (2004) 893-934", "categories": [ "math.GT" ], "abstract": "We give a useful classification of the metabelian unitary representations of pi_1(M_K), where M_K is the result of zero-surgery along a knot K in S^3. We show that certain eta invariants associated to metabelian representations pi_1(M_K) --> U(k) vanish for slice knots and that even more eta invariants vanish for ribbon knots and doubly slice knots. We show that our vanishing results contain the Casson-Gordon sliceness obstruction. In many cases eta invariants can be easily computed for satellite knots. We use this to study the relation between the eta invariant sliceness obstruction, the eta-invariant ribbonness obstruction, and the L^2-eta invariant sliceness obstruction recently introduced by Cochran, Orr and Teichner. In particular we give an example of a knot which has zero eta invariant and zero metabelian L^2-eta invariant sliceness obstruction but which is not ribbon.", "revisions": [ { "version": "v3", "updated": "2004-10-27T20:35:46.000Z" } ], "analyses": { "subjects": [ "57M25", "57M27", "57Q45", "57Q60" ], "keywords": [ "casson-gordon invariants", "slice knots", "eta invariant sliceness obstruction", "casson-gordon sliceness obstruction", "zero eta invariant" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }