Sebastian Hensel

About me Research Teaching Other

Research

My research lies at the intersection of low-dimensional topology and geometric group theory. I mainly study algebraic and geometric properties of mapping class groups, handlebody groups and the spaces they act on. Recently I have been very interested in the action of these groups on the homology of finite covers.

Short notes

Out(Fn) does not lift to the handlebody group

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Preprints

Homological Approximations to the Handlebody Group

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Nielsen Realisation for two-dimensional right-angled Artin groups
(joint with Dawid Kielak)
Submitted.
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arXiv:1410.1618

Accepted For Publication

Rigidity and Flexibility for Handlebody Groups
To appear in Commentarii Mathematici Helvetici.
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arXiv:1608.03094
Convex cocompact subgroups of Out(F_n)
(joint with Ursula Hamenstädt)
To appear in Groups, Geometry, and Dynamics.
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arXiv:1411.2281
Relative Nielsen Realisation by Gluing: Limit Groups and Free Products
(joint with Dawid Kielak)
To appear in the Michigan Journal of Mathematics.
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arXiv:1601.02187
Exponential Torsion Growth for Random 3-Manifolds
(joint with Hyungryul Baik, David Bauer, Ilya Gekhtman, Ursula Hamenstädt, Thorben Kastenholz, Bram Petri, Daniel Valenzuela)
to appear in International Mathematics Research Notices.
The set of uniquely ergodic IETs is path-connected
(joint with Jon Chaika)
To appear in Ergodic Theory and Dynamical Systems.
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SAGE code
arXiv:1405.0767

Published Articles

Moving homology classes in finite covers of graphs
(joint with Benson Farb)
Israel Journal of Mathematics, Vol. 220, Issue 2 (2017), pp. 605-615
Published Version PDF
arXiv:1509.09253
Finite covers of graphs, their primitive homology, and representation theory
(joint with Benson Farb)
New York Journal of Mathematics, Volume 22 (2016) 1365-1391
Published Version
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arXiv:1610.08819
1-slim triangles and uniform hyperbolicity for arc and curve graphs
(joint with Piotr Przytycki and Richard Webb)
Journal of the European Mathematical Society, Volume 17, Issue 4 (2015).
Published Version
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arXiv:1301.5577
Realisation and dismantlability
(joint with Damian Osajda and Piotr Przytycki)
Geometry and Topology, Volume 18, Issue 4 (2014).
Published Version
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arXiv:1205.0513
Isoperimetric inequalities for the handlebody groups
(joint with Ursula Hamenstädt)
Transactions of the American Mathematical Society 365 (2013).
Published Version
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arXiv:1109.5255,
Spheres and projections for Out(Fn)
(joint with Ursula Hamenstädt)
Journal of Topology 8 (2015).
Published Version
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arXiv:1109.2687
The geometry of the handlebody groups I: Distortion
(joint with Ursula Hamenstädt)
Journal of Topology and Analysis, Volume 4, Issue 1 (2012).
Published Version
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arXiv:1101.1838
The ending lamination space of the five-punctured sphere is the Nöbeling curve
(joint with Piotr Przytycki)
London Math. Soc. 84 (1) (2011).
Published Version
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arXiv:0910.3554
Iterated Grafting and Holonomy Lifts of Teichmüller space
Geometriae Dedicata Volume 155, Number 1 (2011)
Published Version
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arXiv:0802.3290