1,613 research outputs found
Contributions to Khovanov Homology
Khovanov homology ist a new link invariant, discovered by M. Khovanov, and
used by J. Rasmussen to give a combinatorial proof of the Milnor conjecture. In
this thesis, we give examples of mutant links with different Khovanov homology.
We prove that Khovanov's chain complex retracts to a subcomplex, whose
generators are related to spanning trees of the Tait graph, and we exploit this
result to investigate the structure of Khovanov homology for alternating knots.
Further, we extend Rasmussen's invariant to links. Finally, we generalize
Khovanov's categorifications of the colored Jones polynomial, and study
conditions under which our categorifications are functorial with respect to
colored framed link cobordisms. In this context, we develop a theory of
Carter--Saito movie moves for framed link cobordisms.Comment: 77 pages; PhD thesis, Zurich, 200
A spanning tree model for Khovanov homology
We use a spanning tree model to prove a result of E. S. Lee on the support of
Khovanov homology of alternating knots.Comment: 13 pages, 3 figures; Footnote 1 was changed, a remark was rephrased
as a theorem, a reference was added, typos were correcte
Khovanov Homology and Conway Mutation
We present an easy example of mutant links with different Khovanov homology.
The existence of such an example is important because it shows that Khovanov
homology cannot be defined with a skein rule similar to the skein relation for
the Jones polynomial.Comment: 9 pages, 5 figure
On Gradings in Khovanov homology and sutured Floer homology
We discuss generalizations of Ozsvath-Szabo's spectral sequence relating
Khovanov homology and Heegaard Floer homology, focusing attention on an
explicit relationship between natural Z (resp., 1/2 Z) gradings appearing in
the two theories. These two gradings have simple representation-theoretic
(resp., geometric) interpretations, which we also review.Comment: 17 pages, 5 figures, to be submitted to Proceedings of Jaco's 70th
Birthday Conference, 201
Charge profile of surface doped C60
We study the charge profile of a C60-FET (field effect transistor) as used in
the experiments of Schoen, Kloc and Batlogg. Using a tight-binding model, we
calculate the charge profile treating the Coulomb interaction in a mean-field
approximation. The charge profile behaves similarly to the case of a continuous
space-charge layer, in particular it is confined to a single interface layer
for doping higher than ~0.3 electron (or hole) per C60 molecule. The morahedral
disorder of the C60 molecules smoothens the structure in the density of states.Comment: 6 pages, 9 figure
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