Entrance hall of the ICMS Workshop

Semigroup Representations 2013

Apr 10, 2013 - Apr 12, 2013

ICMS, 15 South College Street


Name Institution
Lawson, Mark Heriot-Watt University

Invited speakers:
Ruy Exel, Universidade Federal de Santa Catarina, Brazil
Robert Gray, Universidade de Lisboa, Portugal
Peter Higgins, University of Essex, UK
Zur Izhakian, Universitatat Bremen, Germany
Johannes Kellendonk,  Université Claude Bernard - Lyon I, France
Wolfgang Krieger, Heidelberg University
Ganna Kudryavtseva, University of Ljubljana, Slovenia
Daniel Lenz, Jena University, Germany
Stuart Margolis, Bar Ilan University, Israel
Volodymyr Mazorchuk, Uppsala University, Sweden
Jan Okninski, Warsaw University, Poland
Pedro Resende, Instituto Superior Técnico, Portugal
Pedro Silva, University of Porto, Portugal

The goal of this workshop will be to discuss some of the new ideas emerging from the study of semigroup representations. The term representation theory has taken on a rather narrow meaning in recent years suggesting mainly group representations and their connections with particle physics. Important though these are, semigroups also have representations which are both interesting in themselves and for their applications. Two classes of representations form the core of this workshop: those emerging from linear representations and their generalizations, and those involving inverse semigroups and their interactions with C*-algebras.

Please note that there will be no contributed talks, however there will be plenty of time in the programme for informal discussions and meetings.

The workshop is supported by the EPSRC grant EP/1033203/1

Group Photographs

Group photo 1

Group photo 2


The workshop will begin early on Wednesday 10 April, and close at 12.00 on Friday 12 April 2013. Please note these timings when planning your travel and accommodation.


ICMS has arranged accommodation for speakers and full details have been emailed.  If you have not heard about your accommodation please contact: audrey.brown@icms.org.uk

Talks will be 55 minutes long.

Please read the 'General Information' section below for information and advice about the venue, facilities, travel etc. 


A limited number of places on this workshop are available now for application.  If you would like to be considered for one of these places please use this application form

Registration Fee
A registration fee of 50.00 GBP is now payable. This fee will include morning and afternoon coffee/tea and lunch each day (other than Friday).  This should be paid by FRIDAY 5 APRIL by completing the details on this credit/debit card payment form.   As email is not secure, please print the form and return it by fax using the fax number at the top of the form.   ICMS will take your payment and a receipt will be emailed to you.  Alternatively, we can accept sterling cheques, made payable to Heriot-Watt University but sent to Audrey Brown, ICMS, 15 South College Street, Edinburgh, EH8 9AA.  If you have any difficulty in paying in advance, please email Audrey Brown (audrey.brown(at)ICMS.org.uk).   For Speakers and Session Chairs only - no registration fee is required.   


Travel and Accommodation
Applicants are expected to arrange and pay for your own travel and accommodation. 
ICMS is unable to reserve accommodation for you.  However, some suggestions for places to stay are:

  • Jurys Inn Edinburgh, 43 Jeffrey Street, Edinburgh EH1 1DH (approx 75.00-90.00 GBP per night)
    +44 (0)131 200 3300 - www.jurys-edinburgh-hotels.com
    Only a 5 minute walk from ICMS. 
  • Edinburgh City Hotel, 79 Lauriston Place, Edinburgh, EH3 9HZ
    +44 (0)131 622 7979 - http://www.edinburghcityhotel.com/
    If you wish to book and receive the ICMS rate of 65.00 GBP per night, please do NOT book on-line.  Instead, simply email Nicola Faulkner at,  revenue@edinburghcityhotel.com .  Please ensure that you put Nicola Faulkner's name in your email and ask for the ICMS rate. 
  • Edinburgh First, The University of Edinburgh, 18 Holyrood Park Road, Edinburgh EH16 5AY  (approx 50.00-60.00 GBP per night)
    800 028 7118 (UK only) - +44 (0)131 651 2189 - www.edinburghfirst.co.uk
    University of Edinburgh accommodation. Kenneth MacKenzie Hospitality Suite is only a few minutes walk from ICMS.  Pollock Halls is about a 20-25 minute walk.  Masson House at Pollock Halls is very suitable.  

Further details and many more suggestions for accommodation can be found here.



Venue and Talks
The workshop will be held at ICMS, 15 South College Street, Edinburgh, Scotland.  You may also find this map useful for the workshop.   The Lecture Theatre is equipped with a data projector, computer, visualiser (the new generation of overhead projection) and two blackboards.  The projector and one board may be used simultaneously.  It is best to bring your presentation on a memory stick to use in our ICMS computer.   Alternatively, it is possible for you to use your own laptop with our data projector, but please be aware that you may have to alter your laptop resolutions/settings.

More on facilities: www.icms.org.uk/information/facilities

Please read the summary below. Go to www.icms.org.uk/information.php for more details.

Click here for information about travel to the UK

Click here for a printable map in PDF

By train: From Waverley Railway Station (NOT Haymarket!) walk 10 minutes over North and South Bridge to ICMS at 15 South College Street.

By plane: Airport bus Airlink to Waverley Bridge (near Waverley Railway Station)  Airlink - GBP 3.50 (single) 6.00 (return). Taxi one way - approximately 20.00 GBP.

By car: 15 South College Street does not have its own car park.  There is limited on-street parking in the area. It is expensive and designed for short stays. There are two car parks within walking distance of ICMS. One is in Blackfriars Street, just off the Royal Mile and the other is in the at St John's Hill, on the Pleasance.

Local transport: Lothian buses: GBP 1.50 (single journey), GBP 3.50 (day ticket). Please note that the exact fare is required and no change is given.

Please ensure that you have adequate travel insurance covering medical and other emergencies. 

If you do require a UK visa, on request ICMS can provide a signed letter which may assist in your application.

Morning and afternoon coffee/tea will be provided.  A light buffet lunch will be provided on Wednesday and Thursday. There will be an informal wine reception after the talks on Wednesday 10 April at ICMS.



Please continue to check the Programme as it may be subject to alteration until the time of the workshop.

Wednesday 10 April 2013


Morning Session Chair: Nick Gilbert (Heriot-Watt University)


Registration & coffee


Victoria Gould (University of York)


Stuart Margolis (Bar Ilan University)
Representation theory of finite semigroups and combinatorial applications


Coffee/Tea in Chapterhouse, Level 1


Jan Okninski (Warsaw University)
Faithful representations of algebras and semigroups


Lunch provided in the Chapterhouse


Afternoon Session Chair: John Fountain (University of York)


Volodymyr Mazorchuk (Uppsala University)
Linear representations of semigroups from 2-categories


Robert Gray (Universidade de Lisboa)
Finite Gröbner-Shirshov bases for plactic algebras and biautomatic structures for plactic monoids


Coffee/Tea in Chapterhouse


Zur Izhakian (Universität Bremen)
Supertropical algebra and representations


Informal Wine Reception in Atrium, Level 3


Disperse for dinner


Thursday 11 April


Morning Session Chair: László Márki (MTA Rényi Institute)


Johannes Kellendonk (Université Claude Bernard - Lyon I)
The local structure of aperiodic media


Coffee/Tea in Chapterhouse


Daniel Lenz (Jena University)
Order based constructions of groupoids from inverse semigroups


Wolfgang Krieger (Heidelberg University)
A construction of subshifts and a class of semigroups 


Lunch provided in the Chapterhouse


Afternoon Session Chair: Filipa Almeida (Universidade de Lisboa)


Ganna Kudryavtseva (University of Ljubljana)
Etale groupoids and their morphisms


Pedro Resende (Instituto Superior Técnico)
Inverse semigroups and groupoids via quantales


Coffee/Tea in Chapterhouse


Ruy Exel (Universidade Federal de Santa Catarina )
Tight representations of inverse semigroups


Disperse for dinner


Friday 12 April


Final Session Chair: John Meldrum (University of Edinburgh)


Pedro Silva (University of Porto)
Boolean representations of simplicial complexes


Coffee/Tea in Chapterhouse


Peter Higgins (University of Essex)
Burrows-Wheeler transformations and de Bruijn sequences


Valediction: Nik Ruskuc (University of St Andrews)


Close of workshop




Presentation Details
Exel, Ruy
Tight representations of inverse semigroups
View Abstract Down
Gray, Robert
Finite Gröbner-Shirshov bases for plactic algebras and biautomatic structures for plactic monoids
View Abstract Down
Higgins, Peter
Burrows-Wheeler transformations and de Bruijn sequences
View Abstract Down
Izhakian, Zur
Supertropical algebra and representations
View Abstract Down
Kellendonk, Johannes
The local structure of aperiodic media
View Abstract Down
Krieger, Wolfgang
A construction of subshifts and a class of semigroups
View Abstract Down
Kudryavtseva, Ganna
Etale groupoids and their morphisms
View Abstract Down
Lenz, Daniel
Order based constructions of groupoids from inverse semigroups
View Abstract Down
Margolis, Stuart
Representation theory of finite semigroups and combinatorial applications
View Abstract Down
Mazorchuk, Volodymir
Linear representations of semigroups from 2-categories
View Abstract Down
Okniński, Jan
Faithful representations of algebras and semigroups
View Abstract Down
Resende, Pedro
Inverse semigroups and groupoids via quantales
View Abstract Down
Silva, Pedro
Boolean representations of simplicial complexes
View Abstract Down


Name Institution
Afara, Bassima Heriot-Watt University
Alali, Amal Heriot-Watt University
Almeida, Filipa Universidade de Lisboa
Alyamani, Nouf Heriot-Watt University
Ánh, Pham Ngoc MTA Rényi Institute
Bailey, Alex University of Southampton
Brough, Tara University of St Andrews
Dékány, Tamás SZTE, Bolyai Institute
Dombi, Erzsebet University of Strathclyde
Duncan, Andrew Imperial College London
Exel, Ruy Universidade Federal de Santa Catarina
Finn-Sell, Martin University of Southampton
Forsberg, Love Uppsala University
Fountain, John University of York
Gabbay, Jamie Heriot-Watt University
Gilbert, Nick Heriot-Watt University
Gould, Victoria University of York
Gray, Robert Universidade de Lisboa
Hartmann, Miklos University of York
Higgins, Peter University of Essex
Izhakian, Zur Universitatat Bremen
Janin, David Université de Bordeaux
Kambites, Mark University of Manchester
Kellendonk, Johannes Université Claude Bernard - Lyon 1
Korbelar, Miroslav Masaryk University, Czech Republic
Krieger, Wolfgang Heidelberg University
Kudryavtseva, Ganna University of Ljubljana
Lawson, Mark Heriot-Watt University
Lenz, Daniel Jena University
Loughlin, Nicholas Newcastle University
Margolis, Stuart Bar-Ilan University
Márki, László MTA Rényi Institute
Mazorchuk, Volodymir Uppsala University
Meldrum, John University of Edinburgh
Okniński, Jan Warsaw University
Renshaw, Jim University of Southampton
Resende, Pedro Instituto Superior Técnico
Rida, Zenab University of York
Ruskuc, Nik University of St Andrews
Silva, Pedro University of Porto
Szakacs, Nora SZTE Bolyai Institute
Vdovina, Alina Newcastle University
Wallis, Alistair Heriot-Watt University
Wilding, David University of Manchester