- decision problems,
- links between group theory and formal language theory,
- the theory of automatic groups and group combings,
- the language theoretical complexity of the word problem,
- the theoretical and practical development of algorithms in group theory.
- Rachael Boyd, Ruth Charney, Sarah Rees and Rose Morris-Wright, The Artin monoid Cayley graph, to appear in Journal of Combinatorial Algebra.
- Derek Holt and Sarah Rees, The compressed conjugacy problem in relatively hyperbolic groups, submitted for publication.
- Andrew Duncan, Alex Evetts, Derek F. Holt and Sarah Rees, Using EDT0L systems to solve some equations in the solvable Baumslag-Solitar groups, to appear in J. Algebra.
- Sarah Rees, The development of the theory of automatic groups, in `In the tradition of Thurston II', K. Oshika and A. Papadopoulos (editors), 449--473, Springer 2022.
- Barbara Baumeister, Derek Holt, George Neaime and Sarah Rees, Proving isomomorphism and non-isomomorphism for interval groups of type Dn, to appear in J. Alg.
- Barbara Baumeister, Derek Holt, George Neaime and Sarah Rees, Interval groups related to finite Coxeter groups, part II, to appear in Transactions of the LMS.
- Barbara Baumeister, George Neaime and Sarah Rees, Interval groups related to finite Coxeter groups I, Algebraic Combinatorics 6 (2023) 471--506
- Derek Holt and Sarah Rees, The compressed word problem in relatively hyperbolic groups, Journal of Algebra 607 (2022), Part B,305--343.
- Susan Hermiller, Derek Holt, Sarah Rees and Tim Susse, Automaticity for graphs of groups, Geometry, Groups and Dynamics 15 (2021) 503--551.
- Derek Holt, and Sarah Rees, Biautomatic structures in systolic Artin groups, Int. J. Algebra and Computation Int. J. Algebra and Computation 31 (2021) 365--391
- Laura Ciobanu, Derek Holt, and Sarah Rees, Equations in groups that are virtually direct products, J. Algebra 516 (2018) 149--171.
- Patrick Dehornoy, Derek F. Holt and Sarah Rees, Multifraction reduction IV: Padding and Artin-Tits monoids of sufficiently large type , J. Pure and Applied Algebra 222 (2018) 4082--4098.
- Laura Ciobanu, Derek Holt, and Sarah Rees, The generalised word problem in hyperbolic and relatively hyperbolic groups, J. Algebra 516 (2018) 149--171.
- Gabriele Nebe, Richard Parker and Sarah Rees, A method for building permutation representations of finitely presented groups, in Proceedings of Finite Simple Groups: Thirty Years of the Atlas and Beyond, Princeton 2015.
- Derek F. Holt and Sarah Rees, Some closure results for C-approximable groups, Pac. J. Math. 287-2 (2017) 393--409.
- Eddy Godelle and Sarah Rees, Rewriting systems in sufficiently large Artin-Tits groups, J. Alg. 466 (2016) 284--307.
- Laura Ciobanu, Derek Holt and Sarah Rees, Rapid decay and Baum-Connes for large type Artin groups, TAMS 368 (2016) 6103--6129.
- My review of the film The Imitation Game, which appeared in the Newsletter of the Association for Women in Mathematics (AWM), March-April 2015, 17--19.
- Laura Ciobanu, Susan Hermiller, Derek Holt, and Sarah Rees, Conjugacy languages in groups, Israel J. Math. 211 (2015) 311--347.
- Derek F. Holt and Sarah Rees, Conjugacy in Artin groups of extra-large type, J. Alg. 434 (2015) 12--26.
- Laura Ciobanu, Derek Holt and Sarah Rees, Sofic groups: graph products and graphs of groups, Pac. J. Math. 271 (2014) 53--64.
- Mark Lawson, Liam O'Carroll and Sarah Rees, David Rees 1918-2013, Semigroup Forum 88 (2014) 513-522.
- Derek F. Holt and Sarah Rees, Shortlex automaticity and geodesic regularity in Artin groups, Groups, Complexity and Cryptology 5 (2013) 1--23.
- Laura Ciobanu, Derek F. Holt and Sarah Rees, Rapid Decay is Preserved by Graph Products, Journal of Topology and Analysis 5 (2013) 225--237.
- Derek F. Holt and Sarah Rees, Generalising some results about right-angled Artin groups to graph products of groups, Journal of Algebra 371 (2012) 94--104.
- Derek F. Holt and Sarah Rees,
Artin groups of large type are shortlex automatic with regular geodesics,
*Proc. London Math. Soc 104*(2012) 486--512. - Derek F. Holt, Sarah Rees, Claas E. Röver,
Groups with Context-Free Conjugacy Problems,
*Int. J. Alg. Comput. 21*(2011) 193-216. - Derek F. Holt, Sarah Rees and Michael Shapiro,
Groups that do and do not have growing context-sensitive word problem,
*Int. J. Alg. Comput. 18*(2008) 1179-1191. - Susan Hermiller, Derek Holt and Sarah Rees,
Groups whose geodesics are locally testable,
*Int. J. Alg. Comput.*18 (2008) 911-923. - Robert H. Gilman, Susan Hermiller, Derek F. Holt and Sarah Rees,
A characterisation of virtually free groups,
*Archiv der Math.*89 (2007) 289--295 - Sarah Rees,
The automata that define representations of monomial algebras,
*Algebras and Representation Theory*11 (2008) 207--214. - Oliver Payne and Sarah Rees,
Computing subgroup presentations using
the coherence arguments of McCammond and Wise,
*J. Alg.*300 (2006) 109--133 (Leedham-Green birthday volume). - Susan Hermiller, Derek Holt and Sarah Rees,
Star-free geodesic languages for groups,
*Int. J. Alg. Comp.*17 (2007) 329--345. - Michael Batty, Sam Braunstein, Andrew Duncan and Sarah Rees, Quantum algorithms in group theory, Computational and experimental group theory, 1--62, Contemp. Math., 349, Amer. Math. Soc., Providence, RI, 2004
- Derek F. Holt, Sarah E. Rees, Claas E Röver, and Richard M. Thomas, Groups with context-free co-word problem, Journal of the London Mathematical Society 71 (2005) 643-- 657.
- Sarah Rees, How hard is the word problem?, in Proceedings of Conference for European Women in Mathematics, Varna, Bulgaria, September 2002.
- Derek F. Holt and Sarah Rees, Regularity of quasigeodesics in a hyperbolic group,, Internat. J. Alg. Comp. 13 (2003) 585--596.
- Derek F. Holt and Sarah Rees,
Solving the word problem in real time,
*J. London Math. Soc.*63 (2001), 623--639. - George Havas, Derek F. Holt, P.E.Kenne and Sarah Rees,
Some challenging group presentations,
*J. Austral. Math. Soc.*67 (1999) 137--163. - Sarah Rees and Leonard H. Soicher,
An algorithmic approach to fundamental groups and
covers of combinatorial cell complexes,
*Symb. J. Comput.*29 (2000) 59--77. - Robert H. Gilman, Derek F. Holt and Sarah Rees,
Combing nilpotent and polycyclic groups,
*Inter. J. Alg. Comput.*9 (1999) 135--155. - Derek F. Holt and Sarah Rees,
Computing with abelian sections of finitely presented groups,
*J. Algebra*214 (1999) 714--728. - Sarah Rees,
Hairdressing in groups: a survey of combings and formal languages,
*Geometry and Topology Monographs*1 (1998), The Epstein Birthday Schrift, paper no. 24, pages 493-509. - Sarah Rees,
A language theoretic analysis of combings,
*Contemp. Math.*250, 117--136 - Sarah Rees,
Automatic groups associated with word orders other than shortlex,
*Inter. J. Alg. Comput.*8 (1998), 575--598.

Professor Emerita,

School of Mathematics, Statistics and Physics,

University of Newcastle

Newcastle NE1 7RU

UK

Email: Sarah(DOT)Rees@newcastle(DOT)ac(DOT)uk

*quotpic*, an interactive graphics package to compute and display quotients of a finitely present group, and*testisom*, which attempts to test for isomorphism between two finitely presented groups, both developed jointly with Derek Holt, and available from the Warwick mathematics ftp-archive. as a joint package*isom_quotpic*.- automata,
a suite of programs, developed with David Epstein
and Derek Holt, to constructively
verify that a finitely presented group is shortlex automatic. Now superceded
by Derek Holt's
*kbmag*package, which is available from the Warwick mathematics ftp-archive. and contains my own code to test for automaticity with respect to other word orders than shortlex. *matrix group algorithms*developed jointly with Derek Holt, Charles Leedham-Green and Eamonn O'Brien, and now part of the matrix package within the GAP system- I have contributed to the magnus system, developed by the New York Group Theory Cooperative, led by Gilbert Baumslag.

(these are generally for my personal use)

- Authenticated password access to Newcastle University facilities.
- My link to Newcastle University library. The search facility in on this page, and from that I have password access to MathSciNet, JCR, and journals to which Newcastle has electronic access.
- Newcastle's page about videoconferencing
- School wiki, which also has access only by password.
- Secure entry to the the outlook e-mail service in Newcastle.
- List of upcoming Geometry and Algebra Seminars at Newcastle

- the North British Geometric Group Theory Seminar .
- the archive on Mactutor of the British Mathematical colloquium
- the EPSRC's useful list of its grants on the web
- the arXiv