FOM: Midwest Model Theory Meeting, November 11-12

Stephen G Simpson simpson at math.psu.edu
Mon Nov 6 11:32:57 EST 2000

From: Patrick Speissegger <speisseg at math.wisc.edu>
Subject: MWMT'00
Date: Sun, 05 Nov 2000 08:50:01 -0600

MWMT '00: Preliminary Program
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The year's meeting will be held on the weekend of November 11-12, 2000
at the Department of Mathematics, University of Wisconsin, Madison.
Maps, visitor information and driving directions are available at
Steffen Lempp's homepage
http://kleene.math.wisc.edu/~lempp/main.html#info.

Mail questions or comments to: Patrick Speissegger, e-mail
speisseg at math.wisc.edu

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All lectures take place in room B239 Van Vleck Hall.

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Saturday, Nov. 11

0830-0930    Coffee, muffins, etc.  (at the 9th floor lounge of Van
Vleck Hall)

0930-1030    Matthias Aschenbrenner (University of Illinois,
Urbana-Champaign):  Ideal Membership in Polynomial Rings over the
Integers

Abstract: Let \$f_0, f_1,\dots,f_n\$ be polynomials
in the indeterminates \$(C,X)\$ with integer coefficients, where \$C =
(C_1,...,C_M)\$ is a tuple of parametric variables and \$X =
(X_1,...,X_N)\$. Then for each field \$K\$ the set of \$c\$ in \$K^M\$ such
that \$f_0(c,X)\$ belongs to the ideal generated in \$K[X]\$ by
\$f_1(c,X),\dots,f_n(c,X)\$ is a constructible subset of \$K^M\$, that
is, definable by a quantifier-free formula in the language of
rings. (This classical theorem, in an equivalent formulation, is
usually accredited to Grete Hermann, 1926, although it was probably
already proved in some form or another by Julius K\"onig, 1903.) The
purpose of this talk is to sketch a proof of an analogue of this
statement for polynomial rings over the integers.

1045-1145    Martin Grohe (University of Illinois, Chicago):  TBA

1200-1300    Jean-Philippe Rolin (Universite de Bourgogne, Dijon,
France):  Geometric proofs of model theoretic properties

Abstract : We present different geometric methods
for proving some model theoretic properties for several classes of
sets. These properties are mainly o-minimality, model-completeness
and quantifier elimination. Moreover, we show how some metric
properties , such as existence of Lipschitz stratifications or
estimation of volumes can be deduced from these proofs.

1300-1430    Lunch Break

1430-1530    Shawn Hedman (University of Maryland, College Park):
Finite Variable Axiomatizability and Local Modularity

Abstract: We show that any locally modular almost
strongly minimal theory can be completely axiomatized by sentences of
C^k (k variable logic with counting quantifiers) for some k.  We
discuss the situation for nonlocally modular theories.  It can be
shown that Hrushovski's new strongly minimal sets cannot be
axiomatized by sentences of C^k for any k.  Whether the theory of
algebraically closed fields of a given characteristic admits such an
axiomatization is Robinson's 6th problem and remains open.

1530-1600    Coffee Break  (9th floor lounge)

1600-1700    Byunghan Kim (MIT, Boston):  Stable local forking

Abstract: 1) Stable local forking theory was
developed in early 90s, before simplicity era, by Pillay and
Hrushovski. 2) Recently discovered definability theory in simple
context tells us that stable definability theory worked out at least
to supersimple case. But oddly enough, the development takes reverse
order of stable case.  Here we study nice interplay between the above
mentioned 1) stable local forking and 2) simple definability
theory. Many interesting features between stable forking, canonical
bases and elimination of hyperimaginaries were revealed.  E.g., if
low \$T\$ has strong stable forking, then canonical bases come from
stable formulas, hence \$T\$ has elimination of
hyperimaginaries. (Joint work with A.  Pillay)

2000            Party at Patrick's house

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Sunday, Nov. 12

0830-0930    Coffee, Muffins, etc.   (9th floor lounge)

0930-1030    Rahim Moosa (University of Illinois, Urbana-Champaign):
TBA

1045-1145    Andrei Morozov (Russian Academy of Sciences, Novosibirsk,
and Novosibirsk State University):  TBA

1200-1300    Artur Piekosz (Cracow University of Technology):
Semilinear and semialgebraic loci of o-minimal sets

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We have a small number of travel grants available for graduate students
who wish to come to the conference but cannot find funding elsewhere.
(speisseg at math.wisc.edu).

Most nonlocal participants will be staying at the following hotels:

Lowell Hall
610 Langdon Street
Phone: (608) 256-2621

and

601 Langdon Street
Phone: (608) 257-4391.

Both hotels are at a comfortable 10-15 min. walk from the math
department.  At this time, there is no guarantee that these hotels
still have rooms available.  However, when making a reservation,
mention the Midwest Model Theory Meeting and the UW Math Department.
(Reservations for invited speakers and supported graduate students
have been taken care of.  If you are one of them and do not know