# Papers and preprints

62. The Euler characteristic of Out(F_n), (with M. Borinsky, arXiv:1907.03543 . |

61. Cube complexes and abelian subgroups of automorphism groups of RAAGs, (with B. Millard), to appear in Mathematical Proceedings of the Cambridge Philosophical Society, arXiv:1902.00871. |

60. On the bordification of Outer space, (with K.-U. Bux and P. Smillie), J. London Math Soc. 98, Issue 1 (2018), 12–34. |

59. The topology and geometry of automorphism groups of free groups, Proceedings of the 2016 European Congress of Mathematicians, EMS Publishing House, Zurich (2018), 181-202. |

58. Tethers and homology stability for surfaces, (with A. Hatcher), Algebr. Geom. Topol. 17 (2017), no. 3, 1871–1916. |

57. Contractibility of Outerspace:reprise, Hyperbolic Geometry and Geometric Group Theory, Advanced Studies in Pure Mathematics 73 (2017), Math. Soc. Japan, 265–280. |

56. Outer space for untwisted automorphisms of right-angled Artin groups, (with R. Charney and Nathaniel Stambaugh), Geom. Topol. 21 (2017), no. 2, 1131–1178. |

55. Assembling homology classes in automorphism groups of free groups, (with J. Conant, A, Hatcher and M. Kassabov), Commentarii Math. Helv. 91 (2016), 751-806. |

54. GL(n, Z), Out(Fn) and everything in between: automorphism groups of RAAGs, London Mathematical Society Lecture Note Series 422: Groups St Andrews 2013, 105-127, Cambridge University Press, 2015. |

53. Higher hairy graph homology, (with J. Conant and M. Kassabov), Geometriae Dedicata 176 (2015), 345-374. |

52. On the geometry of Outer space, Bull. Amer. Math. Soc. (N.S.) 52 (2015), no. 1, 27–46. |

51. Actions of arithmetic groups on homology spheres and acyclic homology manifolds, (with M.R. Bridson, F. Grunewald and B. Zimmermann), Math. Z. 276 (2014), no. 1-2, 387–395. |

50. Hairy graphs and the unstable homology of M(g,s), Out(Fn) and Aut(Fn), (with J. Conant and M. Kass- abov), J Topology (2013) 6(1): 119-153. |

49. The Dehn functions of Aut(Fn) and Out(Fn) (with M. R. Bridson), Annales de l’institut Fourier, 62 no. 5 (2012), p. 1811-1817. |

48. Abelian covers of graphs and maps between outer automorphisms of free groups, (with M. R. Bridson), Math. Ann. 353 (2012), no. 4, 1069-1102. |

47. Subgroups and quotients of automorphism groups of RAAGs, (with R. Charney), Low-dimensional and Symplectic Topology - Proceedings of Symposia in Pure and Applied Math., Michael Usher ed University of Georgia, Editor - AMS, 2011. |

46. What is Outer space?, Notices of the AMS 55, No. 7 (2008) 784-786. |

45. Automorphisms of two-dimensional RAAGs and partially symmetric automorphisms of free groups, (with 44. K.-U. Bux and R. Charney), Groups, Geometry and Dynamics 3 (4) (2009) 541-554. |

43. Actions of automorphism groups of free groups on spheres and acyclic manifolds, (with Martin Bridson), Commentarii Math. Helv. 86 (1) (2011) |

42. Automorphisms of higher-dimensional right-angled Artin groups, (with Ruth Charney), Bull. London Math Soc. (41) February (2009) 94-102. |

41. A presentation for Aut(Fn), (with H. Armstrong and B. Forrest), J. of Group Theory 11 (2008), 267- 276. |

40. Automorphism groups of right-angled Artin groups, (with Ruth Charney), Guido’s book of conjectures, L’Enseignement Mathematiques Monographie No. 40, 2008. |

39. Automorphisms of two-dimensional right-angled Artin groups, (with Ruth Charney and John Crisp), Geometry & Topology 11 (2007) 2227-2264. |

38. Morita classes in the homology of Aut(Fn) vanish after one stabilization, (with Jim Conant), Groups, Geometry and Dynamics 2 (1) (2008) 121-138. |

37. The cohomology of automorphism groups of free groups, Proceedings of the International Congress of Mathematicians, Madrid 2006, European Mathematical Society Publishing House, Zurich, 2006. |

36. Erratum to: Homology stability for outer automorphism groups of free groups,(with A. Hatcher and N.Wahl), Algebr. Geom. Topol. 6 (2006), 573–579. |

35. Automorphismsoffreegroups,surfacegroupsandfreeabeliangroups,(withMartinBridson),inProblems on Mapping Class Groups and Related Topics, ed. by B. Farb, Proc. Symp. Pure Math. 74, Amer. Math. Soc., Providence RI, (2006). |

34. Automorphisms of free groups and outer space, Proceedings of the Conference on Geometric and Com- binatorial Group Theory, Part I (Haifa, 2000). Geom. Dedicata 94 (2002), 1–31. |

33. Geometry of the space of phylogenetic trees (with L. Billera and S. Holmes), Advances in Applied Math 27 (2001), 733-767. |

32. Automorphisms of automorphism groups of free groups (with M. R. Bridson), J. Algebra 229 (2000), no. 2, 785–792. |

31. The symmetries of Outer space (with M. R. Bridson), Duke Math Journal 106 (2001), 391–409. |

30. A Whitehead algorithm for surface groups (with G. Levitt), Topology 29. (2000), no. 6, 1239–1251. |

28. An Equivariant Whitehead algorithm and conjugacy for roots of Dehn twists (with S. Krstic and M. Lustig), Proceedings of the Edinburgh Math Society 44 (2001), 117-141. |

27. Rational homology of Aut(Fn) (with A. Hatcher), Mathematical Research Letters 5 (1998), 759-780. |

26. The complex of free factors of a free group (with A. Hatcher), Quart. J. Math. Oxford Ser. (2) 49 (1998), |

25. Cerf theory for graphs (with A. Hatcher), J. London Math. Soc., 58, part 3 (1998), 633-655. |

24. A group-theoretic criterion for Property FA, (with M. Culler), Proc. Amer. Math. Soc. 124 (1996), no. 3, 677-683. |

23. Homology stability for outer automorphism groups of free groups, 37. (with Allen Hatcher), Algebr. Geom. Topol. 4 (2004), 1253-1272. |

22. Homology stability for outer automorphism groups of free groups, (with Allen Hatcher), Algebr. Geom. Topol. 4 (2004), 1253-1272. |

21. Morita classes in the homology of automorphism groups of free groups, (with Jim Conant), Geom. Topol. 8 (2004), 1471-1499. |

20. Cut vertices in commutative graphs, (with James Conant and Ferenc Gerlits), Quart. J. Math 56(3) (2005), 321-336. |

19. On a theorem of Kontsevich, (with Jim Conant), Algebr. Geom. Topol. 3 (2003) 1167-1224. |

18. Infinitesimal operations on graph complexes, (with James Conant), Math. Ann. 327 (2003), 545–573. |

17. Homomorphisms from automorphism groups of free groups, (with Martin R. Bridson), Bull. London Math. Soc. 35 (2003), no. 6, 785–792. |

16. On the geometry of the group of automorphisms of a free group (with M. Bridson), Bull. London Math. Soc. 27 (1995), 544-552. |

15. Isoperimetric inequalities for automorphism groups of free groups (with A. Hatcher), Pacific J. Math. 173 (1996), no. 2, 425-441. |

14. End invariants of the group of outer automorphisms of a free group, Topology 14 (1995) no. 3, 533-545.. |

13. Length functions and outer space (with J. Smillie), Michigan Math J. 39 (1992) 485-493. 46. |

12. Equivariant Outer space and automorphisms of free-by-finite groups (with S. Krstic), Comment. Math. Helvetici 68 (1993) 216-262. |

11. Automorphisms of SL2 of imaginary quadratic integers, (with J. Smillie) Proc. A.M.S. 112 (1991) no. 3 |

10. The boundary of outer space in rank two, (with M. Culler) in Arboreal Group Theory (R. Alperin, ed) New York: Springer-Verlag (1991) 189-229. |

9. Local structure of some Out(Fn)-complexes, Proc. Edinburgh Math Soc. 33 (1990), 367-379. |

8. Automorphisms of graphs, p-subgroups of Out(Fn) and the Euler characteristic of Out(Fn), (with J. Smillie) J. Pure and Appl. Algebra 49 (1987), 187-200. |

7. A generating function for the Euler characteristic of Out(Fn), (withJ.Smillie) J.Pure and Appl. Algebra 44 (1987), 329-348. |

6. Moduli of graphs and automorphisms of free groups, (with M. Culler) Inventionnes 84 (1986), 91-119. |

5. Rational homology of Bianchi groups, Math. Ann. 272 (1985), 399-419. |

4. The integral homology of SL2 and P SL2 over Euclidean imaginary quadratic integers, (with J. Schwermer) Comment.Math.Helv. 58(1983)no.4,573-598. |

3. A Stieffel complex for the orthogonal group of a field, Comment. Math. Helv. 57 (1982), no.1, 11-21. |

2. Spherical Posets and homology stability for On,n, Topology 20 (1981), 119-132. |

1. Homology Stability for On,n, Comm. Alg., 7 (1979), no.1., 9-38 |