Downloadble Papers

If a paper is published already, the version below is NOT the published version, but usually the one preceding it. The papers are listed in an approximately reverse chronological order.


  1. Linear Recurrences NEW (An expository note)

  2. Non-Desarguesian planes NEW (An expository note)

  3. Arnol'd, Jacobi identity, and orthocenters NEW VERSION


  1. (with Lizhen Ji) Infinite topology of curve complexes and non-Poincare duality of Teichmüller modular groups

  2. Fifteen problems about the mapping class groups

  3. (with B. Farb) The Torelli geometry and its applications

  4. Examples of centralizers in the Artin braid groups

  5. (with E. Irmak and John D. McCarthy) Automorphisms of surface braid groups


  1. The Lax proof of the change of variables formula, differential forms, a determinantal identity, and Jacobi multipliers

  2. Isometries of Teichmüler spaces from the point of view of Mostow rigidity

  3. Mapping class groups

  4. A topologists view of the Dunford-Schwartz proof of the Brouwer fixed point theorem

  5. A short proof of Gromov non-hyperbolicity of Teichmüller spaces

  6. (with John D. McCarthy) On injective homomorphisms between Teichmüller modular groups

  7. A geometric interpretation of the complex dilatation

  8. Ten Problems on the Mapping Class Groups