On Tuesday, September 9, we will have a LogiCIC seminar with 2 talks by Jeremy Seligman and Thomas Ågotnes.
Everyone is cordially invited!
Venue: Science Park 107, Room F1.15
Date and Time: Tuesday, September 9, 2014, 12:00-14:00 :
12:00-13:00: Jeremy Seligman (University of Auckland)
Title: Exploiting and maintaining network Ignorance
13:00-14:00: Thomas Ågotnes (University of Bergen)
Title: From Distributed to Common Knowledge
Abstract: The topic of the talk is standard notions of group knowledge and belief, with a focus on distributed knowledge. First, I will discuss a natural range of group belief concepts with distributed and general (“everybody-believes”) as the two extreme endpoints and with many intermediate concepts in between. Distributed knowledge is sometimes described as what the members of the group would know of they “pool their knowledge together”. This is inaccurate at best: for example, it is consistent that a group has distributed knowledge of a Moore sentence involving one of the members of the group (a sentence which cannot be known by that member, no matter how much “pooling” has taken place). In the second part of the talk, based on joint work with Yi Wáng, I discuss a new group modality that actually captures what is true after the group have fully shared their information with each other — after their distributed knowledge has been resolved. A key question is: when does distributed knowledge become common knowledge?