Date

Time

Room

Title

Monday, October 5, 2009

4:005:00 pm

BESC 180

Some applications of geometry to logic
Although geometry and logic are subfields that seem far apart,
there are many interesting crossconnections.
We will discuss some of these, in particular how geometric structures such
as sheaves can be used to shed light on what
can and what cannot be proved in specific formalisations of mathematics.
(Monday's lecture should be accessible to a general audience with some
mathematical background.)
Following Monday's lecture, there will be a reception in honor of
Professor Moerdijk at the Koenig Alumni Center, 1202 University Avenue (the SE
corner of Broadway and University).

Wednesday, October 7, 2009

4:005:00 pm

DUAN G125

To what extent is Lie theory for groupoids like that for
groups?
Lie groupoids play an increasingly important role in
foliation theory, symplectic and Poisson geometry, and noncommutative
geometry. In this lecture, we explain how some basic properties of Lie
groups extend to groupoids, and how some other properties don't.
(Wednesday's lecture is independent of the first lecture and requires some
minimal familiarity with Lie groups and/or differential geometry.)

Friday, October 9, 2009

4:005:00 pm

DUAN G125

An extension of the theory of simplicial sets
Simplicial sets form the main combinatorial tool for algebraic
topologists. For example, simplicial sets occur as nerves of categories,
and as such play a central role in algebraic Ktheory. I will sketch a
theory of "dendroidal sets", which contains that of simplicial sets and
allows one to construct the nerves of operads.
The theory involves interesting combinatorial aspects of finite trees.
(Friday's lecture is independent of the first two lectures and will be more
in the style of a topology seminar.)

Ieke Moerdijk

Izak (Ieke) Moerdijk studied Mathematics, Philosophy and General
Linguistics at the University of Amsterdam. He received his PhD in
Mathematics from the same institution in 1985, with the distinction Cum
Laude. Subsequently he worked at the University of Chicago and at the
University of Cambridge, before joining the Mathematics Department of
the University of Utrecht in 1988, where he has been a Professor of
Topology since 1996.
Professor Moerdijk was awarded a Huygens Fellowship from NWO
in 1986 and a PIONIER grant, again from NWO, in 1995. He held visiting
positions at Cambridge (St John's College), Montreal (McGill
University), Sydney (University) and Aarhus, among others.
Professor Moerdijk was elected member of the KNAW (Royal Academy of Arts
and Sciences) in 2006.
Professor Moerdijk's current research interests include algebraic and
differential topology (operads, Lie groupoids, Lie algebroids), and
applications of topological structures in mathematical logic. He is the
coauthor of several wellknown books, including "Sheaves in Geometry and
Logic: a first introduction to topos theory"
with Saunders Mac Lane (SpringerVerlag, 1992, 1994), and "Introduction to
Foliations and Lie Groupoids" with J. Mrcun (Cambridge University Press, 2003).

DeLong Lecture Series

This Lecture Series is funded by an endowment given by Professor Ira M.
DeLong, who came to the University of Colorado in 1888 at the age of 33.
Professor DeLong essentially became the mathematics department by teaching
not only the college subjects but also the preparatory mathematics courses.
Professor DeLong was a prominent citizen of the community of Boulder as
well as president of the Mercantile Bank and Trust Company, organizer of the
Colorado Education Association, and president of the charter convention that
gave Boulder the city manager form of government in 1917. After his death
in 1942, it was decided that the bequest he made to the mathematics
department would accumulate interest until income became available to fund
DeLong prizes for undergraduates and DeLong Lectureships to bring outstanding
mathematicians to campus each year.


