Logic List Mailing Archive

set theory and its neighbours, 25/4, programme (fwd)

Subject: set theory and its neighbours, 25/4, programme

                     Set theory and its neighbours, 9

   Dear Colleague 

       This message is to give further information about the nineth 
   one-day meeting in the series "Set theory and its neighbours", 
   which will take place on on Wednesday 25th April 2001 at the 
   London Mathematical Society building, De Morgan House, 57-58 
   Russell Square, London WC1. The meeting will start at 11am, when 
   coffee will be available, and the first talk will be at 11.30. 
   The last talk should finish at roughly 6pm.

       The speakers at the meeting will be:

11.30  Russell Barker (Oxford), 
    Robinson-type relations and the relationship between the k-size
            and cardinality of finite structures
       Abstract: In this talk I will introduce the notions of L^k, the 
                 restriction of first order logic to k-variables, the
                 k-size of a model and, two conjectures proposed by 
                 Anuj Dawar. Then I shall define define a special kind of
                 relation which I shall call a Robinson-type relation and 
                 prove some results about these relations. I shall go on
                 to give a translation between these relations and the
                 set of L^3 theories and then use the earlier results
                 to disprove Dawar's second conjecture.

12.30  Justin Moore (UEA), 
   What makes the continuum $\aleph_2$?
       Abstract:  I will discuss some of the past, present, and future of
                  the statement "The continuum has size $\aleph_2$."

1.30   Lunch

2.30   Peter Koepke (Bonn), 
   A new fine-structure theory for constructible inner models
       Abstract: We present a natural hierarchy for Godel's model L of
                 constructible sets. The new hierarchy is immediately 
                 adequate for finestructural arguments. This will be 
                 demonstrated by a proof of Jensen's Covering Theorem for L. 
                 Further applications will be discussed.

3.30   Tea

4.00   Iain Stewart (Leicester)
   Finite model theory, computational complexity and program schemes
       Abstract: Finite model theory has strong connections with a number 
                 of topics within computer science. For example, assuming
                 finite structure comes equipped with an ordering of its 
                 elements enables one to logically capture most mainstream
                 complexity classes. However, one cannot always assume that
                 one has access to an ordering of the elements of some finite
                 structure: in database theory, for example, such orderings
                 are almost always not available. In this talk I shall
                 outline the concept of a program scheme, which is
                 essentially a model for computing on arbitrary (not 
                 necessarily ordered) finite structures that sits somewhere
                 between a Turing machine and a logical formula yet remains
                 amenable to logical manipulation. I will show that many 
                 classes of program schemes have alternative formulations 
                 as previously-studied logics from finite model theory but
                 that there are natural classes of program schemes giving 
                 rise to "new" logics with interesting properties.

5.00 Mirna Dzamonja (UEA),
    Combinatorial principles that follow from GCH-like cardinal arithmetic
       Abstract: We discuss various results showing that at certain 
                 cardinals diamond-like principles follow just from 
                 local GCH-like assumptions on cardinal arithmetic.

       More information, including slides from the talks
   will be available as we confirm it via the meetings' web-page:

      As ever, we hope to keep the meeting fairly relaxed, allowing 
   plenty of opportunity for informal discussion. We welcome and encourage
   anyone to participate. You are very welcome simply to turn up on the 
   day if you make a late decision. And we hope as many attendees as 
   possible will be able to come to "DK" for informal discussions at the 
   end of the talks section of the meeting.

      Please do tell anyone about the meeting who you think
   may be interested in it. And let us know if you would 
   like to speak or have ideas for speakers at future meetings.

      We are very grateful to the LMS for allowing us to use De Morgan
   House as a venue.  (De Morgan House is in the south-east corner of 
   Russell Square, The nearest tube station is Russell Square, but 
   De Morgan House is also only a short walk from Euston, Euston Square 
   and Goodge Street stations. See the web-site for maps and similarly
   for directions to "DK".)

            Best regards,