## Buildings and Symmetry

The workshop "Buildings and Symmetry", Monday 25th September to Friday 29th September 2017, will be hosted at the School of Mathematics and Statistics of the University of Western Australia, as part of the activities of the Centre for the Mathematics of Symmetry and Computation. The theme of the workshop is relatively broad, including any aspects of buildings and related objects - although as indicated by the title there is an emphasis on symmetries/group theory/Lie theory aspects. Organisers: Alice Devillers (local organiser), Bernhard Mühlherr, James Parkinson, and Hendrik Van Maldeghem.

##### News

The annual CMSC ECR paper prize was awarded to Melissa Lee's paper "A new infinite family of hemisystems of the Hermitian surface" to appear in Combinatorica. This is joint with John Bamberg, Koji Momihara and Qing Xiang.

John Bamberg and Kyle Rosa have been involved in running activities for school students by the School of Mathematics and Statistics. We have run sessions for Cape Naturaliste College (June 7), Churchlands SHS (July 24), Aspire UWA (May 4 and August 23).

Alice Devillers has joined the AMOC Senior Problems Committee (National Maths Olympiad Problem Committee).

Alice Devillers is now an editor for Innovations in Incidence Geometry: Algebraic, Topological and Combinatorial (previously Innovations in Incidence Geometry, now with a new publisher)

Michael Giudici is now an Associate Editor of the Journal of the Australian Mathematical Society.

John Bamberg is now an editor for Advances in Geometry.

Our Co-tutelle PhD student Sabina Pannek (UWA and RWTH Aachen) visited 12-31 May. Sabina now lives in Bremen with her family.

It was good to have Sherry Seress visit for the first half of June.

Weixi Wang from Nanjing University visited in July and August as part of a six-week research placement program: UWA International Short Term Research Training Program. He was supervised by John Bamberg in a project relating to the foundations of hyperbolic geometry.

Luke Morgan will visit Jin Xin Zhou (Beijing Jiaotong University) in September. He will give a talk in the Algebra Seminar entitled "Locally semiprimitive vertex-transitive graphs"

Congratulations to Hui Zhou, our former visiting student, for receiving his PhD from Peking University! Hui visited UWA from October 2015 to April 2017 and is now a postdoc at Peking University.

Daniel Hawtin has submitted his PhD thesis. Congratulations, Dan!

Tomasz Popiel has accepted an extension of his lectureship at Queen Mary, London, and so has resigned from his research associate position in CMSC. We are sorry to see him go.

Alexander Bors will be a visiting research fellow for two years from October funded by the Austrian Science Foundation.

Binzhou Xia will take up a lectureship at The University of Melbourne in November 2017. We wish him the very best and look forward to developing a new link with The University of Melbourne!

The University of Western Australia has recognised Cheryl Praeger’s immense contribution to the University by naming a Lecture Room in her honour. In June the Faculty of Engineering and Mathematical Sciences held an event to celebrate the opening of this room. An excellent lunch was provided and speeches were made by our Head of School Lyle Noakes, the Faculty Dean John Dell and by Cheryl herself. Then the ceremonial ribbon was cut and the "Cheryl Praeger Lecture Room" was declared open for Mathematics!

##### Visitors

Nick Gill (University of South Wales) 6-10 September.

James Parkinson (University of Sydney) 13-30 September.

Hendrik Van Maldeghem (Ghent University) 12-30 September.

Jeroen Schillewaert (University of Auckland) 16-30 September.

Tom De Medts (Ghent University) 19-29 September.

Bernhard Mühlherr (Giessen university) 20 September-3 October.

##### Groups and Combinatorics Seminars

##### SymOmega

SymOmega is a mathematical blog run by CMSC members John Bamberg, Michael Giudici and Gordon Royle.

##### Conferences

Summer School on Finite Geometry, University of Sussex, Brighton, UK, 26-30 June 2017. Jesse Lansdown attended.

All Kinds of Mathematics Remind me of You: Conference to celebrate the 70th Anniversary of Peter J. Cameron, Lisbon, Portugal, 24-27 July 2017. Michael Giudici and Cheryl Praeger were invited speakers. Stephen Glasby, Luke Morgan, Tomasz Popiel, Gordon Royle and Binzhou Xia attended.

Graph Embeddings and Maps on Surfaces, Podbanské, Slovakia, 30 July-4 August, 2017. Cheryl Praeger was an invited speaker. Michael Giudici, Luke Morgan and Binzhou Xia gave talks.

Groups St Andrews 2017, Birmingham, UK, 5-13 August 2017. Michael Giudici, Stephen Glasby, Luke Morgan, Tomasz Popiel, Cheryl Praeger and Binzhou Xia attended. In fact, several former members of the CMSC were also present at the conference: Joanna Fawcett, Melissa Lee, Simon Smith and his partner Clara Finley, Tomasz Popiel, Eric Swartz, Gabriel Verret. We also met with a new member to arrive in October: Alexander Bors. It was a great pleasure to see everyone!

Summer School on Finite Groups and Related Geometrical Structures 2017, Dobbiaco, Italy, 28 August-8 September. Saul Freedman and Kyle Rosa attended.

Finite Geometries: Fifth Irsee Conference, Irsee, Germany, 10-16 September 2017. John Bamberg was an invited speaker. Jesse Lansdown and Tomasz Popiel attended.

Summer school: Permutation Groups, organized by the Research Training Group Experimental and constructive algebra, RWTH Aachen University, Germany, 18-22 September 2017. Cheryl Praeger will be a main speaker. Saul Freedman, Jesse Lansdown and Tomasz Popiel will attend.

The Heidelberg Laureate Forum 2017, Heidelberg, Germany, 24-29 September. Saul Freedman will attend.

WIMSIG Conference 2017: Celebration of Women in Australian Mathematical Sciences, University of South Australia, 24-26 September 2017. Cheryl Praeger will be part of the panel on "The gender equity landscape in Australian mathematical sciences"

Buildings and Symmetry, University of Western Australia, Australia, 25-29 September 2017. Alice Devillers is the local organiser. John Bamberg is an invited speaker. Cheryl Praeger will give a talk.

5th International Combinatorics Conference (5ICC), Monash University, Australia, 4-9 December 2017. Michael Giudici and Luke Morgan will attend.

The Tutte Centenary Retreat, Matrix Mathematical Research Institute, Melbourne, 26 November-2 December. Michael Giudici, Luke Morgan, Cheryl Praeger and Gordon Royle will attend.

##### Papers

### Published papers

Jehan Al-Bar, Ahmad Al-kenani, Najat Muthana and Cheryl. E. Praeger, Finite edge-transitive oriented graphs of valency four with cyclic normal quotients, Journal of Algebraic Combinatorics 46 (2017) 109-133.

Teng Fang, Xin Gui Fang, Binzhou Xia and Sanming Zhou, Vertex-imprimitive symmetric graphs with exactly one edge between any two distinct blocks, Journal of Combinatorial Theory, Series A 152 (2017) 303-340.

Neil Gillespie and Cheryl E. Praeger, New characterisations of the Nordstrom-Robinson codes, Bulletin of the London Mathematical Society 49 (2017) 320-330.

Michael Giudici, S. P. Glasby, Cai Heng Li and Gabriel Verret, The number of composition factors of order p in completely reducible groups of characteristic p, Journal of Algebra490 (2017) 241-255.

Michael Giudici and Binzhou Xia, Vertex-quasiprimitive 2-arc-transitive digraphs, Ars Mathematica Contemporanea 14 (2018) 67-82.

Luke Morgan, Joy Morris and Gabriel Verret, Characterising CCA Sylow cyclic groups whose order is not divisible by four, Ars Mathematica Contemporanea 14 (2018) 83-95.

Binzhou Xia, Quasiprimitive groups containing a transitive alternating group, Journal of Algebra 490 (2017) 555-567.

Binzhou Xia, The covering radius of PGL2(q), Discrete Mathematics 340 (2017) 2469-2471.

### Accepted papers

Adel Alahmadi, S. P. Glasby and Cheryl E. Praeger, On the dimension of twisted centralizer codes, to appear in Finite Fields and Their Applications.

Mohammed Aljohani, John Bamberg and Peter J. Cameron, Synchronization and separation in the Johnson schemes, to appear in Portugaliae Mathematica.

John Bamberg, Tomasz Popiel and Cheryl E. Praeger, Simple groups, product actions, and generalised quadrangles, to appear in Nagoya Mathematical Journal.

Binzhou Xia, Cyclotomic difference sets in finite fields, to appear in Mathematics of Computation.

Yian Xu, On constructing normal and non-normal Cayley graphs, to appear in Discrete Mathematics.

### Submitted papers

John Bamberg, Anurag Bishnoi and Gordon F. Royle, On regular induced subgraphs of generalized polygons.

John Bamberg, Saul D. Freedman and Luke Morgan, On p-Groups With Automorphism Groups Related To The Chevalley Group G_2(p).

John Bamberg and Tim Penttila, Euclidean geometry is incidence geometry.

John Bamberg, Ferdinand Ihringer, Jesse Lansdown, Gordon Royle, The binary q-analogue of the Fano plane has a trivial automorphism group.

A. Gardiner and Cheryl E. Praeger, Symmetric graphs with complete quotients.

Michel Lavrauw and Tomasz Popiel, The symmetric representation of lines in PG(F^3\otimes F^3).