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Group actions and cohomology in non-positive curvature


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19th June 2017 to 23rd June 2017
Alessandra Iozzi
Mladen Bestvina
Brian Bowditch

Workshop Theme

The workshop is the closing event of the semester-long program "Non-positive curvature, Group Actions, and Cohomology".  It is intended as a moment to wrap up the activities, reflecting the vibrant atmosphere of the programme.  In addition to providing a forum to disseminate the results obtained during the semester, the workshop will focus on cohomology, which, in several different incarnations, has come to be one of the standard tools to study group actions in non-positive curvature.   The following topics will serve as a centrepiece of the workshop:

  • Bounded cohomology
  • CAT(0) cube complexes
  • $\ell^2$-betti numbers
  • the Farrell-Jones conjecture
  • $\ell^2$-torsion
  • the Chern conjecture

The synergy between the energy generated by the programme and the recent exciting developments in the above topics will provide an inspiring starting point for future important research.


Confirmed speakers

  • Yael Algom Kfir
  • Grigori Avramidi
  • Juliette Bavard
  • Michelle Bucher
  • Matt Clay
  • Roberto Frigerio
  • Eriko Hironaka
  • Dawid Kielak
  • Bruno Klingler
  • Jean-François Lafont
  • Ian Leary
  • Christopher Leininger
  • Clara Löh
  • Denis Osin
  • Kasra Rafi
  • Roman Sauer
  • Kevin Schreve
  • Jing Tao
  • Karen Vogtmann


Deadline for applications: 2 April 2017

Apply now

Please note that there is a limited amount of external funding for young participants to cover the registration fee for this workshop, which will be allocated at the Workshop Organisers’ discretion.

Please note members of Cambridge University are welcome to turn up and sign in as a non-registered attendee on the day(s) during the workshop and attend the lecture(s). Please note that we cannot provide you with any support including name badge, meals or accommodation.

In addition to visiting the INI, there are multiple ways in which you can participate remotely.



Registration Only    
  • Registration Package: £227
  • Student Registration Package: £177

The Registration Package includes admission to all seminars, lunches and refreshments on the days that lectures take place (Monday - Friday), wine reception and formal dinner, but does not include other meals or accommodation.

Formal Dinner Only
  • Formal Dinner: £50

Participants on the Registration Package, including organisers and speakers, are automatically included in this event. For all remaining participants who would like to attend, such as programme participants, the above charge will apply.


Unfortunately we do not have any accommodation to offer so all successful applicants will need to source their own accommodation.  Please see the Hotels Combined website for a list of local hotels and guesthouses.



Lunch will be served at Wolfson Court in the Cafeteria from 12:30 to 13:30 on days that lectures take place.

  • Accommodation Package and Registration Package participants should present their badge as payment for their meal
  • Those issued with a blue Institute door entrance card can add money onto the card via the Porters' Lodge at Wolfson Court
  • Other participants must purchase their meal using their dining card via the Porters' Lodge (forms can be found on the registration desk or at the Porters' Lodge)

Evening Meal

Participants are free to make their own arrangements for dinner.

Formal Dinner

The Formal Dinner will take place on Wednesday 21st June at Christ's College. Participants on the Registration Package, including organisers and speakers, are automatically included in this event.


Supported by:

University of Cambridge Research Councils UK
    Clay Mathematics Institute London Mathematical Society NM Rothschild and Sons