North British Semigroups and Applications Network


NBSAN is a network of researchers in Scotland and Northern England with interests in semigroup theory and its applications. It is funded chiefly by grants from the London Mathematical Society and Edinburgh Mathematical Society, and organises around three meetings per year in different locations around the region. The main participant universities are Heriot-Watt, Manchester, St Andrews and York, but our activities are open to all interested researchers. We especially welcome graduate students.
Next Meeting
The next NBSAN meeting will be announced shortly.
Future Meetings
To receive announcements of future NBSAN meetings, please enter your name and email address below and click "Subscribe". Alternatively, you can email Mark Kambites.
Other forthcoming (non-NBSAN) events which might be of interest include....
- The 4th Novi Sad Algebraic Conference and A Workshop on Semigroups and Applications, in Novi Sad from 5th-9th June 2013.
- International Conference on Geometric, Combinatorial and Dynamics aspects of Semigroup and Group Theory on the occasion of the 60th birthday of Stuart Margolis, Bar Ilan from 11th-14th June 2013.
- GAIA 2013 in celebration of the 65th birthday and retirement of Brian Davey, Melbourne from 15th-19th July 2013.
Past Meetings
The fourteenth NBSAN meeting was held in St Andrews on Tuesday 9th April 2013, organised by Yann Peresse. The speakers were:- Pham Ngoc Ánh - Divisibility, ideal and valuation theory of classical commutative rings
- Victoria Gould - Coherent monoids (slides)
- James Hyde - Sierpinski rank and universal sequences (slides)
- Julius Jonusas - Maximal subsemigroups of the transformation monoid
- Max Neunhöffer - Generalisations of small cancellation (slides)
- David Wilding - Green's D relation for matrices over semirings
The thirteenth NBSAN meeting was held in York on Wednesday 21st November 2012, organised by Victoria Gould. The speakers were:
- Igor Dolinka (Novi Sad) - Finite groups are big as semigroups (slides)
- David Janin (Bordeaux) - Walking in free inverse monoids (slides)
- Peter Jones (Marquette) - The semigroups B_2 and B_0 are inherently nonfinitely based (slides)
- Alex McLeman (St Andrews) - Cayley automaton semigroups (slides)
- Dandan Yang (York) - Free idempotent-generated semigroups (slides)
The twelfth NBSAN meeting (which was the first Young NBSAN meeting) was held at ICMS in Edinburgh on Monday 23rd July 2012, organised by Alex Bailey, Alistair Wallis and Yanhui Wang. The speakers were....
- Suhear Alwan (Essex) - Languages that require full scanning of words to determine membership
- Tara Brough (St Andrews) - Automaton semigroup constructions
- Zsofia Juhasz (Essex) - Congruences induced by Green's relations and the corresponding egg-box pictures
- Mark Kambites (Manchester) - An introduction to the Cerny conjecture (expository talk)
- Bana Al Subaiei (Southampton) - Amalgamation in pomonoids and dominions
- Alina Vdovina (Newcastle) - Short introduction to expander graphs
The eleventh NBSAN meeting was held in Manchester on Wednesday 11th April 2012. The speakers were:
- Des FitzGerald (Tasmania) - Categorification for binary relations (abstract | notes)
- Miklos Hartmann (York) - E-unitary almost factorizable orthodox semigroups (slides)
- Peter Higgins (Essex) - Products in transformation semigroups: work with the late John M. Howie (slides)
- Sarah Rees (Newcastle) - Artin groups and monoids; normal forms and the group word problem (slides)
The tenth NBSAN meeting was held in York on Wednesday 23rd November 2011. The speakers were:
- Peter Cameron - Permutation groups and transformation semigroups (abstract | slides)
- Jean-Eric Pin - Expansions and covers (abstract | slides)
- Rick Thomas - The word problem for semigroups (abstract | slides)
- Yanhui Wang - Weakly U-abundant semigroups (abstract | slides)
The ninth NBSAN meeting was held in Manchester on Tuesday 30th August 2011. The speakers were:
- Alex Bailey (Southampton) - Flat covers of acts over monoids
- Victoria Gould (York) - Restriction semigroups (an expository talk) (slides)
- Robert Gray (Lisbon) - Structures with lots of symmetry (handout slides | overlay slides)
- Christopher Hollings (Oxford) - The perils of taking shortcuts: embedding semigroups in the 1930s (slides)
- Lubna Shaheen (York) - Model companions of S-posets
The eighth NBSAN meeting was held at the University of St Andrews on Thursday 19th and Friday 20th May 2011. The speakers were:
- Alan Cain (Porto) - Hyperbolic and word-hyperbolic semigroups (slides)
- Si Craik (St Andrews) - Ends of semigroups (slides)
- Andrew Duncan (Newcastle) - Rewriting systems and the geodesic problem for words and cycles
- John Fountain (York) - An inverse monoid approach to Thompson's group V and generalisations (slides)
- Marianne Johnson (Manchester) - Green's J-order and the rank of tropical matrices (slides)
- Dave Jones (Heriot Watt) - Graph Inverse Semigroups (slides)
- Mark Kambites (Manchester) - An Introduction to Tropical Matrix Semigroups
- Alistair Wallis (Heriot Watt) - Rees monoids, self-similar groups and fractals (slides)
The seventh NBSAN meeting was held at the University of York on Wednesday 24th November 2010. The speakers were:
- Bassima Afara (Heriot-Watt) - The Rees theorem and its generalizations (slides)
- Peter Jones (Marquette) - Varieties of P-restriction semigroups (slides)
- Volodymyr Mazorchuk (Uppsala) - Kiselman type semigroups
- Maria Szendrei (Szeged) - Some results on almost factorisable semigroups (slides)
- Alexei Vernitski (Essex) - Graphs to semigroups (slides)
The sixth NBSAN meeting was held at the University of Manchester on Monday 26th July 2010. The speakers were:
- Zur Izhakian (Bar Ilan) - Supertropical algebra
- Erzsi Dombi (Glasgow) - Automatic semigroup acts
- Rick Thomas (Leicester) - FA-presentable semigroups
The fifth NBSAN meeting was held at the University of St Andrews on Friday 7th and Saturday 8th May 2010, organised by James Mitchell. Speakers were:
- Andreas Distler (St Andrews) - How to store 10 semigroups in a bit
- James East (Sydney) - Generators and relations for monoids of block bijections and partitions
- Attila Egri-Nagy (Hertfordshire) - Coordinatizing finite permutation groups and transformations semigroups - computational considerations
- Victoria Gould (York) - Bisimple inverse semigroups as semigroups of quotients
- Zsofia Juhasz (Essex) - The smallest operation-compatible quasiorders containing Green's quasiorders
- Zak Mesyan (Ben Gurion) - Conjugation of injections by permutations
- Markus Pfeiffer (St Andrews) - Semigroups with easily solveable word problem
- Steve Pride (Glasgow) - On diagram groups
- Abdullahi Umar (Sultan Qaboos) - Some combinatorial properties of semigroups of partial transformations
The fourth NBSAN meeting was held at the University of York on Wednesday 25th November 2009, organised by Victoria Gould. Speakers were:
- Claire Cornock (York) - Structure theorems for proper restriction semigroups
- Nick Gilbert (Heriot-Watt) - Approaches to tiling semigroups
- Michael Hoffmann (Leicester) - Hyperbolic monoids
- Marianne Johnson (Manchester) - Tropical matrix algebra
- Jim Renshaw (Southampton) - Adequate transversals of abundant semigroups (abstract | slides)
- Lubna Shaheen (York) - Perfection for pomonoids
The third NBSAN meeting was held on 23rd July 2009 at Heriot-Watt University in Edinburgh, organised by Mark Lawson. The speakers were:
- Chris Eilbeck (Heriot-Watt) - Weierstrass arithmetic semigroups and algebraic curves
- Jennie Hansen (Heriot-Watt) - Using probability theory to study the full transformation monoid
- Peter Higgins (Essex) - Set products in transformation semigroups
- Stuart Margolis (Bar-Ilan) - On some monoids associated to Coxeter groups
- James Mitchell (St Andrews) - Generating uncountable transformation semigroups
The second NBSAN meeting was held in St Andrews on 16th and 17th April 2009. The speakers were:
- João Araújo (Lisbon) - Guess Who
- Alan Cain (Lisbon) - Automaton Semigroups
- Robert Gray (St Andrews) - Homotopical and Homological Finiteness Conditions of Monoids and their Subgroups
- Mark Kambites (Manchester) - Free Adequate Semigroups
- Vesna Kilibarda (Indiana Northwest) - Ends for Semigroups and Monoids
- Valdis Laan (Tartu) - Tensor Products and Preservation of Weighted Limits for S-posets
- Mark Lawson (Heriot-Watt, expository talk) - The Morita Theory of Regular Semigroups
- László Márki (Rényi Institute) - A Matrix Construction for certain Inverse Monoids with an Application in Universal Algebra
The inaugural NBSAN meeting was held in York on 28th January 2009, and was dedicated to the memory of Professor Douglas Munn (1929-2008). The speakers were:
- John Fountain (York, expository talk) - The Mathematical Work of Douglas Munn and its Influence
- Nik Ruskuc (St Andrews, open problem talk) - One Relation Semigroups
- Rebecca Noonan Heale (Heriot-Watt) - Green's Relations for Semigroup Graph Expansions
- Yann H. Peresse (St Andrews) - Generating Transformation Semigroups using Endomorphisms of Preorders, Graphs and Similarity Relations
- Pedro V. Silva (Porto) - The Generalized Conjugacy Problem for Virtually Free Groups
- Jorge Almeida (Porto) - The Mysteries of Free Profinite Semigroups: a Sneak Preview
