Colloquium Announcement
Department of Mathematics
West Virginia University
for
Thursday, December 11, 1997, at 3:45pm
in 324 Armstrong Hall
(Tea and cookies begin at 3:00 in coffee room.)
Professor Dorota Rogowska
Lodz Technical University, Poland
Some properties of \Sigma^0_2-supported \sigma-ideals in Polish spaces.
The talk will be suitable for a general audience.
Students are strongly encouraged to participate.
Abstract
In 1995 Kechris and Solecki obtained an interestig characterization of
\Sigma^0_0-supported \sigma-ideals in a Polish space X.
We show two kinds of applications of that theorem.
One of them gives the solution of Mauldin's
problem about the values of Baire orders for the functions continuous I-almost
everywhere (if I is a given \sigma-ideal on X).
Another application shows that for a \Sigma^0_2-supported \sigma-ideal
I satisfying the countable chain condition on X there exists a Polish
topology \tau having the same Borel sets as the original topology and such that
I is the \sigma-ideal of \tau-meager sets.
The information on the future (and past) Colloquia can be also found on web at the
address:
http://www.math.wvu.edu/homepages/kcies/colloquium.html