WORD-HYPERBOLIC
GROUPS
FALL 2001 MATH 415 Section
D1
MWF, 11am Altgeld
Hall, rm 441
WWW:
http://www.math.uiuc.edu/~kapovich/415-01/415-01.html
Telephone:
265-0633
e-mail: kapovich@math.uiuc.edu. (Preferred method
of reaching me!)
Office location: Illini Hall, room 328
Office hours: Tuesday, Friday, 3-4pm
AND by appointment
TEXTBOOK:
There is no assigned textbook for this course. We will be using several
articles as our primary sources. All of those will be directly supplied
by the instructor to the course participants.
Here are some of the sources that we will use for of
the course (we shall start with those in red):
-
"Notes on word-hyperbolic groups", by J.M.Alonso,
T.Brady, D.Cooper, V.Ferlini, M.Lustig, M.Mihalik, M.Shapiro, H.Short;
in Group Theory from a Geometric Viewpoint, World Scientific, 1991, pp.
3-63
-
"The Theory of negatively curved spaces and
groups", by J.Cannon; in "Ergodic Theory, Symbolic Dynamics and Hyperbolic
Spaces", Oxford University Press, 1991, pp. 315-368
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"Metric Spaces of Non-Positive Curvature", by M.Bridson and A.Haefliger;
Springer-Verlag, 1999 (selected chapters)
-
"Greenberg's theorem for quasiconvex subgroups of word hyperbolic groups",
by I.Kapovich and H.Short; Canadiand J. Math 48 (1996), no. 6, pp.
1224-1244
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"On Hausdorff-Gromov convergence and a theorem of Paulin", by M.Bridson
and G.Swarup; Enseign. Math. (2) 40 (1994), no. 3-4,
pp. 267-28
-
"Hyperbolic groups", by M.Gromov; Essays in group theory, 75--263,
Math. Sci. Res. Inst. Publ., 8, Springer, New York, 1987 [this monograph
is recommended ONLY for reference purposes!]
-
"Cut points and canonical splittings of hyperbolic groups", by B.Bowditch;
Acta Math. 180 (1998), no. 2, pp. 145-186
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"Cannon-Thurston maps for hyperbolic group extensions", by M.Mitra;
Topology 37 (1998), no. 3, pp. 527-538
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"Word Processing in Groups", by D.Epstein, J.Cannon,
D.Holt, S.Levy, M.Paterson, and W.Thurston; Jones and Bartlett
Publishers, Boston, MA, 1992 (selected topics)
-
"Finite subgroups of hyperbolic groups", by N.Brady; Internat. J.
Algebra Comput. 10 (2000), no. 4, pp. 399-405
-
"A combination theorem for negatively curved groups", by M.Bestvina
and M.Feighn; J. Differential Geom. 35 (1992), no. 1, pp. 85-101
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"The fixed group of an automorphism of a word hyperbolic group is rational",
by W.Neumann; Invent. Math. 110 (1992), no. 1, pp. 147-150
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"Almost every group is hyperbolic", by A.Yu. Ol'shanskii;
Internat. J. Algebra Comput. 2 (1992), no. 1, pp. 1-17
-
"Combinatorial Group Theory", by R.Lyndon and P.Schupp;
Ergebnisse der Mathematik und ihrer Grenzgebiete, Band 89. Springer-Verlag,
Berlin-New York, 1977
Syllabus (very approximate):
-
Introduction to Geometric Group Theory. Cayley graphs, Quasi-isometries
and Geometric Actions.
-
Gromov-Hyperbolic metric spaces and word-hyperbolic groups.
-
Divergence of geodesics. Quasigeodesics and quasiconvex subsets in hyperbolic
spaces.
-
Isoperimetric functions and Dehn algorithm.
-
Hyperbolic groups are automatic.
-
Hyperbolicity and Quasi-isometries. Equivalence of various definitions
of hyperbolicity. Sources of hyperbolic groups and hyperbolicity as a generic
property.
-
Conjugacy Problem in Hyperbolic groups.
-
Rips Complex and basic cohomological properties of hyperbolioc groups.
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Finite subgroups of hyperbolic groups.
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Hyperbolic boundary: topological and metric structure.
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Basic subgroup properties of hyperbolic groups.
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Action on the boundary as a convergence action.
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Limit sets and quasiconvexity of subgroups.
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Free and non-free subgroups of hyperbolic groups. Rips' construction.
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Amalgamated free products, HNN extensions and the Combination Theorem.
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Automorphisms of Hyperbolic groups. Neumann's Theorem on the fixed subgroup
of an automorphism.
-
Outer automorphisms, Dehn twists and small actions on R-trees.
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Cannon-Thurston map.
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Bowditch's approach to the JSJ decomposition for hyperbolic groups.
-
Other topics, time permitting