My name is Ilya Kapovich,
and I am a Professor in the Department of
Mathematics and Statistics at the Hunter College of CUNY,
starting from with the Fall 2018 semester.
I am also a member of doctoral faculty at the CUNY Graduate Center.
Contact info:
Department of Mathematics and Statistics, Hunter College
695 Park Avenue
New York, NY 10065
tel. 212-772-5303
e-mail: ik535 at hunter.cuny.edu
The above photo is licensed by under the Creative Commons Attribution-ShareAlike 4.0 license. The photo was taken by Ilya Kapovich in December 2012 at the University of Illinois in Urbana-Champaign.
Here is a
link to my old webpage at the University of Illinois at
Urbana-Champaign.
Here is a link
to the webpage for the Spring 2017 Math 751 General Topology
course I taught at Hunter.
My
research papers in arXiv.
My March 15, 2017 talk at the Hunter College GRECS Seminar, ``Groups
as geometric objects.
My office at Hunter is HE 917, tel. 212-772-5303
My second office, at the CUNY Graduate Center, is in 4214.07
Here is a reasonably up-to-date version of my
CV (October 2022).
Contact information
e-mail ik535@hunter.cuny.edu [preferred
way of contacting me]
office phone 212-772-5303
fax 212-772-4858
office location: Hunter East 917
Mailing address:
Department of Mathematics and Statistics
Room 919/944 East
Hunter College
695 Park Avenue
New York, NY 10065, U.S.A.
* My GoogleScholar profile
* My Math Genealogy Project profile
* My arXiv papers
Geometric Group Theory mailing list.
I currently administer a geometric group theory mailing list geom-group-theory@lists.illinois.edu for announcements about events and positions related to geometric group theory. To submit such an announcement, e-mail it directly to geom-group-theory@lists.illinois.edu.
The list's homepage is located at this link. You can subscribe/unsubscribe to the list there (you can also do that by sending me an e-mail request at ik535@hunter.cuny.edu).
New York Group Theory Seminar.
I am a co-organizer of the New York Group Theory Seminar at the CUNY Graduate Center. In the Fall 2024 semester the seminar meets in a hybrid format, with some in person talks and some online Zoom talks. The in-person talks are on Fridays at 4:15pm in room 5417 at the CUNY Graduate Center. The onine Zoom talks are on Fridays at 4:00pm U.S. eastern time.
I also maintain the NYGT Seminar mailing list. If you would like to receive the weekly announcements, including Zoom links and passwords, for the seminar talks, please e-mail me (from an academic institution affiliated e-mail address) a request to ik535@hunter.cuny.edu.
Videos of prior NYGT Seminar talks are available at the NYGT Youtube channel.
Human rights work
*I served as the Chair of the AMS Committee on the Human Rights of Mathematicians (02/01/2020-01/31/2021)
If you have a matter requiring the committee's attention, please e-mail humanrights@ams.org
*I am a member of the Steering Committee of the AAAS Science and Human Rights Coalition.
*AMS and ICM 2022, letter to the editor, Notices of the American Mathematical Society, volume 68, number 5 (May 2021), pp. 681-682
* The case of Azat Miftakhov
* Putin is distracting the world from his atrocities letter to the editor, Washington Post, February 21, 2022
Publications.
Link
to my papers posted at arxiv.og
I am currently supported by the NSF grant DMS-1905641
- Ilya Kapovich, "On the Hausdorff dimension and attracting laminations for fully irreducible automorphisms of free groups," preprint, 2024; arXiv:2410.02058
- Naomi Andrew, Edgar A. Bering IV, Ilya Kapovich, Stefano Vidussi; with an appendix by Peter Shalen, "On two-generator subgroups of mapping torus groups," preprint, 2024; arXiv:2405.08985
- "Counting
conjugacy classes of fully irreducibles: double exponential
growth", (joint with Catherine Pfaff); Geometriae Dedicata 218 (2024), no. 2, Paper no. 39; DOI: 10.1007/s10711-024-00885-4
- "Ascending chain condition in generic groups," preprint, 2023; arXiv:2306.06706
- "Primitivity rank for random elements in free groups," Journal of Group Theory 25 (2022), no. 5, 823-835
- "Primitivity index bounds in free groups, and the second Chebyshev function" (joint with Zachary Simon) International Journal of Algebra and Computation 33 (2023), no. 1, pp. 105-122
-
"Complexity and Randomness in Group Theory. GAGTA BOOK 1." (By Frederique Bassino, Ilya Kapovich, Markus Lohrey, Alexei Miasnikov, Cyril Nicaud, Andrey Nikolaev, Igor Rivin, Vladimir Shpilrain, Alexander Ushakov, Pascal Weil), De Gruyter, 2020; ISBN 9783110667028
- "Random trees in the boundary of Outer space"
, (joint with Joseph Maher,
Catherine Pfaff, and Samuel Taylor); Geometry & Topology 26 (2022), no. 1, 127-162
- "Generic-case complexity of Whitehead's algorithm, revisited ", preprint arXiv:1903.07040
- "Random outer automorphisms of free groups: Attracting trees and their
singularity structures", (joint with Joseph Maher,
Catherine Pfaff, and Samuel Taylor); Transactions of the American Mathematical Society 375 (2022), no. 1, pp. 525-557
- "Counting
conjugacy classes of fully irreducibles: double exponential
growth", (joint with Catherine Pfaff); preprint
arXiv:1801.07471
- "Counting
conjugacy classes in Out(FN)", (joint
with Michael Hull), Bulletin of the Australian Mathematical
Society 97 (2018), no 3, 412-421
- "Stable Strata
of Geodesics in Outer Space", (joint with Yael
Algom-Kfir and Catherine Pfaff), Internat. Math. Res. Notices
(IMRN) 2019 (2019), no. 14, pp. 4549-4578
- "Detecting
fully irreducible automorphisms: a polynomial time
algorithm. With an appendix by Mark C. Bell",
Experimental Mathematics, 28 (2019), no. 1, pp. 24-38
- "Endomorphisms,
train track maps, and fully irreducible monodromies ",
(joint with Spencer Dowdall and Christopher Leininger),
Groups, Geometry, and Dynamics 11 (2017), no. 4, pp.
1179-1200
- "The primitivity
index function for a free group, and untangling closed
curves on hyperbolic surfaces. With an appendix by Khalid
Bou-Rabee." (joint with Neha Gupta), Mathematical Proceedings of the Cambridge Philosophical Society 166 (2019), no. 1, pp. 83-121 Published version at the publisher's website
- "McMullen
polynomials and Lipschitz flows for free-by-cyclic groups" ,
(joint with Spencer Dowdall and Christopher J. Leininger);
Journal of the European Mathematical Society (JEMS) 19
(2017), no. 11, pp. 3253-3353
- "An integral
weight realization theorem for subset currents on free
groups" , Topology Proceedings 50 (2017), pp.
213-236
- "Wolfgang
Haken: A biographical sketch", Illinois Journal of
Mathematics 60 (2016), no. 1, pp. 3-9; special issue
in honor of Wolfgang Haken
- "Cannon-Thurston
maps for hyperbolic free group extensions", (joint with
Spencer Dowdall and Samuel Taylor), Israel J. Math. 216
(2016), no. 2, pp. 753-797
- "Musings on
generic-case complexity", preprint
- "On purely
loxodromic actions" , Monatshefte fur Mathematik 181
(2016), no. 1, pp. 89-101
- "Conical limit
points and the Cannon-Thurston map" (joint with Woojin
Jeon, Christopher Leininger and Ken'ichi Ohshika), Conformal
Geometry and Dynamics, 20 (2016), pp. 58-80
- "Nielsen
equivalence in a class of random groups" (joint with
Richard Weidmann), Journal of Topology 9 (2016), no.
2, 502-534
- "Patterson-Sullivan
currents, generic stretching factors and the asymmetric
Lipschitz metric for Outer space", (joint with Martin
Lustig), Pacific J. Math. 277 (2015), no. 2, pp.
371-398
- "Dynamics on
free-by-cyclic groups" , (joint with Spencer Dowdall
and Christopher J. Leininger); Geometry and Topology 19
(2015), 2801-2899
- "A train track
directed random walk on $Out(F_r)$" (joint with
Catherine Pfaff), International Journal of Algebra and
Computation 25 (2015), no. 5, pp. 745-798
- "Cannon-Thurston fibers
for iwip automorphisms of $F_N$", (joint with Martin
Lustig), Jour. London Math. Soc. 91 (2015), no. 1,
203-224
- "Unbounded
asymmetry of stretch factors", (joint with
Spencer Dowdall and Christopher J. Leininger); Comptes Rendus
Mathematique, 352 (2014), no. 11, 885-887
- "Algorithmic
detectability of iwip automorphisms", Bull. London Math.
Soc. 46 (2014), no. 2, pp. 279-290; online
version at the BLMS site available here
- "On
hyperbolicity of free splitting and free factor complexes",
(joint with Kasra Rafi), Groups, Geometry and Dynamics, 8
(2014), no. 2, pp. 391-414
- "Quasi-isometric
co-Hopficity of non-uniform lattices in rank-one semi-simple
Lie groups", (joint with Anton Lukyanenko), Conformal
Geometry and Dynamics, 16 (2012), 269-282
- "Spectral
rigidity of automorphic orbits in free groups", (joint
with Mathieu Carette, Stefano Francaviglia and Armando
Martino), Algebraic and Geometric Topology 12 (2012), pp. 1457-1486
"Corrigendum
to ''Spectral rigidity of automorphic orbits in free
groups''", (joint with Mathieu Carette, Stefano
Francaviglia and Armando Martino); Algebraic
and Geometric Topology 14 (2014), no. 5, pp.
3081-3088
- "Subset currents
on free groups", (joint with Tatiana Nagnibeda),
Geometriae Dedicata, 166 (2013), 307-348
- "Invariant
laminations for irreducible automorphisms of free groups",
(joint with Martin Lustig), Quarterly J. Math. 65
(2014), no. 4, pp. 1241-1275 Q. J. Math. (2014)
doi: 10.1093/qmath/hat056
- "Random
length-spectrum rigidity for free groups", Proceedings
of AMS 140 (2012),
no. 5, pp. 1549-1560
- "Stabilizers of
R-trees with free
isometric actions of FN ", (with Martin
Lustig), Journal of Group Theory, 14 (2011), no. 5, pp.
673-694
- "Domains of
proper discontinuity on the boundary of Outer space",(with
Martin Lustig), Illinois J. Math., 54 (2010), no. 1,
pp. 89-108, special issue dedicated to Paul Schupp
- "On
mathematical
contributions of Paul E. Schupp", Illinois J. Math., 54
(2010), no. 1, pp. 1-9, special issue dedicated to Paul Schupp
- "Ping-pong and
Outer space", (with Martin Lustig), Journal of Topology
and Analysis 2 (2010), no. 2, pp. 173-201
- "Nielsen
equivalence in small cancellation groups", (with Richard
Weidmann), preprint
- "Geometric
entropy of geodesic currents on free groups", (with
Tatiana Nagnibeda), Dynamical Numbers: Interplay Between
Dynamical Systems and Number Theory, Contemporary Mathematics
series, American Mathematical Society, 2010, pp. 149-176
- "Intersection
form,
laminations and currents on free groups ", (with Martin
Lustig), Geom. Funct. Anal. 19
(2010), no. 5, pp. 1426-1467
- "Geometric
Intersection Number and analogues of the Curve Complex for
free groups", (with Martin Lustig), Geometry and
Topology 13 (2009), pp. 1805-1833
- "Some
Quantitative Aspects of Fractional Computability", (with
Paul Schupp), preprint
- "On
group-theoretic models of randomness and genericity" (with
Paul Schupp), Groups, Geometry and Dynamics 2 (2008), no. 3, pp.
383-404
- "The
actions of $Out(F_k)$ on the boundary of Outer space and on
the space of currents: minimal sets and equivariant
incompatibility" (with Martin Lustig), Ergodic Theory
and Dynamical Systems 27
(2007), no. 3, pp. 827-847
- "Random
quotients of the modular group are rigid and essentially
incompressible" (with Paul Schupp), Journal fur die reine und
angewandte Mathematik (Crelle's Journal), 628 (2009), pp.
91-119
- "On
the absence of McShane-type identities for the outer space"
(with Igor Rivin), Journal of Algebra 320 (2008), no. 10, pp.
3659-3670
- "Clusters,
currents and Whitehead's algorithm", Experimental
Mathematics 16
(2007), no. 1, pp. 67-76
- "
Densities in free groups and $\mathbb{Z}^k$, Visible Points
and Test Elements" (with Igor Rivin, Paul Schupp and
Vladimir Shpilrain), Math. Research Letters 14 (2007), no. 2, pp.
263-284
- "The
Subadditive Ergodic Theorem and generic stretching factors
for free group automorphisms" (with Vadim Kaimanovich
and Paul Schupp), Israel J. Math. 157 (2007), pp. 1-46
- "Translation
equivalence
in free groups", (with Gilbert Levitt, Paul Schupp and
Vladimir Shpilrain), Transact. Amer. Math. Soc. 359 (2007), no. 4, pp.
1527-1546
- "The
Patterson-Sullivan embedding and minimal volume entropy for
outer space", (joint with Tatiana Nagnibeda), Geom.
Funct. Anal. (GAFA) 17 (2007),
no 4, pp 1201-1236
- "Generic
properties
of
Whitehead's Algorithm and isomorphism rigidity of random
one-relator groups" (with Paul Schupp and Vladimir
Shpilrain), Pacific J. Math. 223
(2006), no. 1, pp. 113-140
- "Currents
on
free groups", Topological and Asymptotic
Aspects of Group Theory (R. Grigorchuk, M. Mihalik, M. Sapir
and Z. Sunik, Editors), AMS Contemporary Mathematics Series,
vol. 394, 2006, pp. 149-176
- "The
frequency
space of a free group", Internat. J. Alg. Comput.
(special Gaeta Grigorchuk's 50's birthday issue), 15 (2005), no. 5-6, pp.
939-969
- "Delzant's
T-invariant,
Kolmogorov complexity and one-relator groups" (with Paul
Schupp), Commentari Math. Helv. 80 (2005), no. 4, pp. 911-933
- "Kleinian
groups
and the rank problem", (with Richard Weidmann), Geometry
and Topology 9
(2005), pp. 375-402
- "Foldings,
graphs
of groups and the membership problem" (with Richard
Weidmann and Alexei Myasnikov), Internat. J. Alg. Comput. 15
(2005), no. 1, 95-128
- "Acylindrical
accessibility
for
groups acting on R-trees" (with Richard
Weidmann), Math. Zeitschrift 249 (2005), no. 4, pp.
773-782
- "Genericity,
the
Arzhantseva-Ol'shanskii
method
and the isomorphism problem for one-relator groups" (with
Paul
Schupp),
Mathematische Annalen 331(2005), no. 1, pp. 1-19
- "Average-case
complexity
and
decision problems in group theory" (with Alexei
Myasnikov, Paul Schupp and Vladimir Shpilrain), Advances in
Mathematics 190 (2005), no. 2, pp. 343-359
- "Relative
hyperbolicity
and
Artin groups"(with Paul Schupp), Geom. Dedicata 107
(2004), no. 1, pp. 153-167
- "Freely
indecomposable
groups
acting on hyperbolic spaces"(with Richard
Weidmann), Internat. J. Algebra and Comput. 14
(2004), no. 2, pp. 115-171
- "Bounded
rank
subgroups
of Coxeter groups, Artin groups and one-relator groups with
torsion" (with Paul Schupp), Proceedings of the London
Mathematical Society 88 (2004), no. 1, pp. 89-113
- "Generic-case
complexity,
decision problems in group theory and random walks" (with
Alexei
Myasnikov, Paul Schupp and Vladimir Shpilrain), J.
Algebra 264 (2003), no. 2, pp. 665-694
- "Nielsen
methods and groups acting on hyperbolic spaces" (with
Richard Weidmann), Geometriae Dedicata 98 (2003), no.
1, pp. 95-121
- "The
Frattini
subgroup
for subgroups of hyperbolic groups", J. Group
Theory 6 (2003), no. 1, pp. 115-126
- "The
non-amenability
of
Schreier graphs for infinite index quasiconvex subgroups of
hyperbolic groups", Ensign. Math. 48 (2002), no.
3-4, pp. 359-375
- "The
geometry
of
relative Cayley graphs for subgroups of hyperbolic
groups", preprint
- "A
remark
on
mapping tori of free group endomorphisms",
preprint
- "Boundaries
of hyperbolic groups" (with Nadia Benakli),
Combinatorial and Geometric Group Theory (R.Gilman, et al,
editors), Contemporary Mathematics, vol. 296, 2002, pp. 39-94
- "A
note on the Poenaru condition", J. Group
Theory 5 (2002), no. 1, pp. 119-127
- "Stallings
foldings and the subgroup structure of free groups" (with
Alexey Myasnikov), J. Algebra 248 (2002), no
2, pp. 608-668, and an
Addendum
- "The
Combination Theorem and Quasiconvexity", Intern.
J. Algebra Comput. 11 (2001), no. 2, pp. 185-216
- "The
subgroup properties of fully residually free groups" ,
Transact. Amer. Math. Soc. 354 (2002), no. 1,
pp. 335-362; and an
ERRATUM , Transact. Amer. Math. Soc.
355 (2003), no. 3, pp. 1295--1296
- "On
the failure of the Co-Hopf property for subgroups of
word-hyperbolic groups" (with Dani Wise),
Israel. J. Math. 122 (2001), pp. 125-147
- "Mapping
tori of endomorphisms of free groups", Comm. in
Algebra 28 (2000), no. 6, pp. 2895-2917
- "Equivalence
of some residual properties for word-hyperbolic groups"(with
Dani Wise), J. Algebra 223 (2000), no. 2,
pp. 562-583
- "
Two-generated groups acting on Trees"(with Richard
Weidmann), Archiv der Mathematik (Basel) 73 (1999),
no. 3, pp. 172-181
- "On
the structure of two-generated word-hyperbolic groups"
(with Richard Weidmann), Math. Z. 231
(1999), no. 4, pp. 783-801
- "One-relator groups and the Howson property", Comm.
in Algebra 27 (1999), no. 3, pp. 1057-1072
- "A
non-quasiconvexity embedding theorem for hyperbolic
groups", Math Proc. Cambridge Phil.
Soc. 127 (1999), no. 3, pp. 461-486
- "Quasiconvexity and amalgams", Intern. J. Alg.
Computation 7 (1997), no. 6, pp. 771-811
-
"Amalgamated products and the Howson Property" ,
Canadian Math. Bulletin, 40 (1997), no. 3, pp.
330-340
- "Small cancellation groups and translation numbers",
Trans. Amer. Math. Soc., 349 (1997), no. 5,
pp. 1851-1875
- "Greenberg's
theorem for quasiconvex subgroups of word hyperbolic
groups" (with Hamish Short), Canadian J. Math., 48
(1996), no. 6, pp. 1224-1244
- "An
example of a non-quasiconvex subgroup of a word hyperbolic
group with an exotic limit set", New York
J. Math., 1 (1995), pp. 184-195
- "Detecting quasiconvexity: algorithmic aspects",
AMS DIMACS series, 25, Geometric and Computational
Perspectives on Infinite Groups, 1995, pp. 91-100
My graduate students
- Lucas Sabalka (PhD 2006, UIUC); an applied mathematician at Nebraska Global
- Gregory Kelsey (PhD 2011, UIUC); Assistant Professor at Bellarmine University
- Brent Solie (PhD 2011, UIUC); Assistant Professor at Embry-Riddle Aeronautical University
-
Patrick Reynolds (PhD 2011, UIUC); Machine learning engineer, Apple
-
Brian Ray (PhD 2014, UIUC); senior analyst at Daniel H. Wagner Associates)
-
Neha Gupta (PhD 2016, UIUC); Director of Math Scheduling, Georgia Tech
-
Caglar Uyanik (PhD 2017, UIUC); Gibbs Assistant Professor, Yale
-
Elizabeth Field (PhD 2020, UIUC); postdoctoral researcher, University of Utah
-
Heejoung Kim (UIUC, current PhD student)
-
Zachary Simon (M.Sc. 2020, City College of CUNY)