##### New appointments

Michael Giudici - Deputy Director

Alice Devillers - Newsletter Editor

##### SymOmega:

SymOmega is a mathematical blog run by three of the CMSC's Mathematicians, Michael Giudici, John Bamberg and Gordon Royle. Read about their recent trips to conferences.

##### Arxiv

Find in one click all the publications of our members that are deposited on the Arxiv.

##### Conferences

### 5th de Bruin Workshop 'Groups, Combinatorics, Computing'

Held at the National University of Ireland, Galway, 11-16 April. Cheryl Praeger was a main lecturer, and gave a lecture course on “ ESTIMATIONS PROBLEMS AND RANDOMIZED GROUP ALGORITHMS (with Alice Niemeyer and Akos Seress)”. *Website*.

### Distinguished Lecturers Series

Cheryl Praeger gave a lecture on "Fifty years of Permutation groups" at this event, University of South Australia, May 3.

### Antalya Algebra Days XIII

In Antalya, May 18–22, 2011, Akos Seress gave an invited talk: "Majorana representations". *Website*.

### Finite Groups and Their Automorphisms

In Istanbul, June 7-11, 2011, Akos Seress gave a lecture series on: "Computing automorphism groups". *Website*.

### Finite and infinite sets

In Budapest, June 13-17, 2011, Akos Seress gave an invited talk: "The diameter of symmetric groups". *Website*.

### Matroid workshop

Gordon Royle attended this conference in La Vacquerie-et-Saint-Martin-de-Castries, South of France, June 2011.

### Finite Geometries, Third Irsee Conference

Several CMSC members attended this conference, in Irsee, Germany on June 19th-25th, 2011. Centre Director Prof. Cheryl Praeger presented an invited talk (Collinearly connected geometries and group triple factorisations). Other attendees from the Centre were John Bamberg, Alice Devillers, Michael Giudici and student Carmen Amarra. *Website*.

### Algebraic graph theory summer school

In Rogla, Slovenia, June 26 - July 2, 2011, Cheryl Praeger, John Bamberg and Michael Giudici collaborated to give a mini-course on "Group actions and quotient graphs". *Website*.

### British Combinatorial Conference 2011

Michael Giudici attended this conference, in Exeter, England, July 4-8, 2011. *Website*.

### The 10th International Conference on Finite Fields and their Applications

In Ghent, July 11-15, 2011. John Bamberg talked about "Projective permutation polynomials and flag-transitive linear spaces" and Alice Devillers about "On quasiprimitive rank 3 permutation groups". *Website*.

### Groups and Semigroups: Interactions and Computations

In In Lisbon, 25-29 July, 2011, Akos Seress will give an invited talk: "Constructive recognition of linear groups in all characteristics’" and Cheryl Praeger will give an invited talk: "Finding Involutions in finite classical groups and symmetric groups". *Website*.

##### Recent visitors

Sabina Pannek, Aachen (June 2010 – June 2011)

Anton Betten, Colorado State University (August - January)

Alexander Hulpke, Colorado State University (October) )

Jan Saxl, Cambridge (December)

Martin Liebeck, Imperial College, London (December)

Joy Morris and Dave Witte Morris, University of Lethbridge ( January – June)

Dillon Mayhew, Victoria University of Wellington (February).

Daniela Bubbuloni and Silvio Dolfi, Univeristy of Firenze (February – April)

Pablo Spiga (March-June)

##### Upcoming visitors

Max Neunhoeffer, University of St Andrews (August 2011).

Simon Guest, Baylor University (September-December 2011).

Tim Burness, Southampton (September 2011).

##### Papers

A. Azad, M. A. Iranmanesh, C. E. Praeger, P. Spiga, Abelian coverings of finite general linear groups and an application to their non-commuting graph , J. Alg. Combin. (to appear, accepted 5/04/2011).

John Bamberg, Anton Betten, Cheryl E. Praeger and Alfred Wassermann. Unitals in the Desarguesian projective plane of order sixteen (submitted).

Bamberg, J and De Clerck, F., A geometric construction of Mathon’s perp-system from four lines of PG(5, 3), Journal of Combinatorial Designs 18 (2010), no. 6, pp. 450–461.

Bamberg, J., De Clerck, F., Durante, N., Intriguing sets of partial quadrangles, Journal of Combinatorial Designs 19 (2011), no. 3, pp. 217–245.

John Bamberg, Alice Devillers, Jeroen Schillewaert, Weighted intriguing sets of finite generalised quadrangles (submitted).

Bamberg, J., Giudici, M., Point regular automorphism groups of generalised quadrangles, Journal of Combinatorial Theory Series A 118 (2011), no. 3, pp. 1114–1128.

John Bamberg, Michael Giudici, Martin Liebeck, Cheryl E. Praeger and Jan Saxl. The classification of almost simple 3/2-transitive groups (submitted).

Bamberg, J., Giudici, M., Royle, G. F., Every flock generalised quadrangle has a hemisystem, Bulletin of the London Mathematical Society 42 (2010), no. 5, pp. 795–810.

Bamberg, J., Giudici, M., Royle, G. F., Hemisystems of small flock quadrangles, Designs, Codes and Cryptography (submitted).

Scott Brown, Michael Giudici, Stephen Glasby and Cheryl E. Praeger, The proportion of cyclic matrices in maximal reducible matrix algebras (submitted).

Timothy C. Burness, Michael Giudici, Robert A. Wilson, Prime order derangements in primitive permutation groups, J. Algebra (to appear).

Andrew D. Cannon, John Bamberg and Cheryl E. Praeger. A classification of the strongly regular generalised Johnson graphs. Annals of Combin. (to appear, accepted 18/03/ 2011).

Philippe Cara, Alice Devillers, Michael Giudici and Cheryl E. Praeger. Quotients of incidence geometries (to appear, accepted 11/02/2011).

Ashraf Daneshkhah and Alice Devillers, A classification of graphs whose subdivision graph is locally distance transitive, Graphs and Combinatorics (to appear, accepted 09/06/2011).

Ashraf Daneshkhah, Alice Devillers and Cheryl E. Praeger, Symmetry properties of Subdivision Graphs, Discrete Math. (to appear, accepted 31/03/2011).

Alice Devillers, Michael Giudici, Cai Heng Li, Geoffrey Pearce and Cheryl E. Praeger, On imprimitive rank 3 permutation groups, J. London Math. Soc. (to appear, accepted 4/02/2011).

Alice Devillers, Michael Giudici, Cai Heng Li and Cheryl E. Praeger, Locally $s$-distance transitive graphs, J. Graph Theory (to appear, accepted 23/11/2010).

Alice Devillers, Michael Giudici, Cai Heng Li and Cheryl E. Praeger, An infinite family of biquasiprimitive 2-arc transitive cubic graphs, J. Alg. Combin. (to appear, accepted 20/05/2011).

Alice Devillers, Wei Jin, Cai Heng Li and Cheryl E. Praeger. On distance, geodesic and arc transitivity of graphs (submitted).

T. Dobson, Cai Heng Li, Pablo Spiga, Transitive permutation groups with a regular abelian Hall subgroup, Comm. Algebra (to appear).

Silvio Dolfi, R. M. Guralnick, Marcel Herzog and Cheryl E. Praeger, A new solvability criterion for finite groups, J. London Math. Soc. ((to appear, accepted 26/04/2011).

Dong, F.M, Royle, G.F and Wagner D. Chromatic Roots of a Ring of Four Cliques, Electronic Journal of Combinatorics (to appear).

W. W. Fan, D. Lemans, Cai Heng Li and J. M. Pan, Locally 2-arc-transitive complete bipartite graphs (submitted).

Y. Q. Feng, Cai Heng Li and J. X. Zhou, Symmetric cubic graphs with sovable automorphism groups (submitted).

Michael Giudici, Cai Heng Li, Geoffrey Pearce and Cheryl E. Praeger, Basic and degenerate pregeometries (submitted).

Michael Giudici, Geoffrey Pearce and Cheryl E. Praeger, Basic coset geometries. J. Alg. Combin. (submitted).

Michael Giudici, Geoffrey Pearce, Cheryl E. Praeger, Basic coset geometries (submitted).

R. Gray, H. D. Macpherson, Cheryl E. Praeger and G. F. Royle. Set-homogeneous directed graphs (submitted).

Kung J.P. and Royle, G.F. Graphs whose flow polynomials have only integer roots. European Journal of Combinatorics, Volume 32, Issue 6, August 2011, 831-84.

Cai Heng Li, Ben Gong Lou, Finite locally-primitive arc-transitive graphs (submitted).

Cai Heng Li, Z. P. Lu, A classification of edge-transitive tetravalent Cayley graphs of square-free order (submitted).

Cai Heng Li, Z. P Lu and J. M. Pan, Finite vertex-quasiprimitive edge-transitive metacirculants (submitted).

Cai Heng Li, Z. P. Lu and G. X. Wang, On edge-transitive graphs of square-free order (submitted).

Cai Heng Li and L. Ma, On locally primitive graphs, and bi-direct products of graphs, J. Aust. Math. Soc. (to appear).

Cai Heng Li, J. M. Pan, Finite quasiprimitive permutation groups which contains a transitive metacyclic subgroup (submitted).

Cai Heng Li, L. M. Pan, S. J.Song and D. J. Wang, A class of edge-transitive metacirculans (submitted).

Cai Heng Li and Cheryl E. Praeger. On finite permutation groups with a transitive cyclic subgroup (submitted).

Cai Heng Li, Shou Hong Qiao, Finite groups of 4th-power free order (submitted).

Cai Heng Li, Shujiao Song and Dianjun Wang, Finite locally-quasiprimitive graphs, Algebra Colloquium (to appear).

Cai Heng Li, S. J. Song and D. J. Wang, Classifying a family of edge-transitive metacirculant graphs, J. Algebraic Combin. (to appear).

Cai Heng Li, S. J. Song and D. J. Wang, Finite permutation groups with a regular dihedral subgroup, and edge-transitive dihedrants (submitted).

Cai Heng Li, S. J. Song and D. J. Wang, On edge-transitive Frobenius metacirculants, (submitted).

Cai Heng Li, Hua Zhang, On finite 2-path-transitive graphs, (submitted).

Cai Heng Li, Hua Zhang, The finite primitive and bi-primitive 2-path-transitive graphs, (submitted).

Cai Heng Li, Hua Zhang, Finite vertex-biprimitive edge-transitive tetravelnt graphs (submitted).

Steve Linton, Yohei Negi and Alice C. Niemeyer and Cheryl E. Praeger, Finding permutations containing long cycles in finite alternating and symmetric groups acting on subsets (submitted).

Mayhew, D and Royle, G.F. The Internally 4-connected binary matroids with no M(K_5\backslash e) minor (submitted).

Alice C. Niemeyer, Tomasz Popiel and Cheryl E. Praeger. Abundant p-singular elements in finite classical groups (submitted).

Alice C. Niemeyer, Tomasz Popiel, Cheryl E. Praeger and Sukru Yalcinkaya. On semiregular permutations of a finite set. Math. Comp. (to appear, accepted 14/11/2010).

Cheryl E. Praeger, Laszlo Pyber, Pablo Spiga and Endre Szabo. The Weiss conjecture for locally primitive graphs with automorphism groups admitting composition factors of bounded rank. , Proc. Amer. Math. Soc. (to appear, accepted 1/03/2011).

Cheryl E. Praeger and Akos Seress. Probabilistic generation of finite classical groups in odd characteristic by involutions, J. Group Theory, Volume 14, Issue 4, 521–545.

Cheryl E. Praeger and Csaba Schneider. Embedding permutation groups into wreath products in product action (submitted).

Pablo Spiga, Cheryl E. Praeger and Gabriel Verret. Bounding the size of a vertex-stabiliser in a finite vertex-transitive graph (submitted).

##### News

The IMU visited UWA for an Executive meeting. On that occasion, the EC members gave a series of talks : MathWest. Following the workshop, most of the IMU Executive made a two day trip to the south-west Western Australia, and in particular, to Bunbury to visit schools from the area; where some 120 students were in attendence. Martin Groetschel spoke again about maths in the real world, from the routing of a garbage collection to the electro-physiology of the heart. Martin’s presentation was followed by an interactive activity given by John and Michael on The game of Nim. There was also an Industry breakfast to celebrate the UWA Year of Mathematics, MCed by Cheryl Praeger. More info in the gazette.

Many of the Centre members were involved in the School’s “Showcase of modern mathematics’’ on 7 June 2011, a day when we welcomed 200 Year 9 and 10 students and introduced them to modern mathematics through talks and various activities.

Hassan Alavi’s PhD Thesis "Triple Factorisations of groups" was passed in March 2011 [supervisors John Bamberg and Cheryl E Praeger].

Brian Corr obtained a teaching internship from UWA, with mentor John Bamberg.

Cheryl Praeger was awarded a 2011 UWA Award for Excellence in Teaching - research supervision.

Cheryl Praeger was Guest Speaker at the Joint AISWA/Catholic Ed WA conference for heads of maths in WA, May 23, Wollaston College.

Cheryl Praeger was appointed Chair, Centre for Industrial and Applied Mathematics, University of South Australia - first meeting was May 4 2011.

Cheryl Praeger was appointed to the ARC College of Experts.

IMU and ICMI commitments for Cheryl Praeger: attended International Program Committee meeting for ICME12 in Jeju, Korea in February; attended Executive Committee meeting of ICMI, in Bejing in February; attended Executive Committee meeting of IMU, in Perth in March.

Cheryl Praeger made a recording used for a radio interview to promote UWA new courses.

Cheryl Praeger took part in the UK International Review of Mathematics (on a review panel in December 2010) and will participate in the Research Council of Norway evaluation of research in mathematics (on a review panel in October 2011).