MAY 6: Rafael Sorkin, Physics, Syracuse U., "Is spacetime a past-finite
poset?" At CCNY. Tea 3:15, NAC 8/133; talk 4:00 NAC 4/113. For parking,
contact R. Kopperman, rdkcc@cunyvm.cuny.edu.
ABSTRACT:
The causal set -- mathematically a locally finite ordered set
or "poset" -- is a candidate discrete substratum for spacetime. I will
introduce this idea and describe some aspects of causal set kinematics,
dynamics, and phenomenology, including, as time permits, a notion of
fractal dimension, a stochastic growth dynamics, and an idea for
explaining some of the puzzling large numbers of cosmology. I will also
mention some questions of mathematical interest that have arisen in this
connection.
MAY 7, Related event: Miniconference: "The finite universe and some
related subjects". Talks, abstracts, location given at
Miniconference Web Page.
There is no registration fee, but please tell Ralph Kopperman, at rdkcc@cunyvm.cuny.edu if you plan to attend. This will help us have
sufficient food at the lunch and teas, and sufficient space at the talks.
MAY 13: Steve Matthews, Computer Science, U. of Warwick, UK, "Partial
metrics and time." Tea 3:15, talk 4:00, Room 6-215 Baruch Coll. Vertical
Campus, Lexington Av. and 24 St. For local information contact A. Todd,
artbb@cunyvm.cuny.edu.
MAY 20: W. W. Comfort, Wesleyan U., "Making group topologies with, and
without, convergent sequences." Tea 3:15, talk 4:00, Room 6-215 Baruch
Coll. Vertical Campus, Lexington Av. and 24 St. For local information
contact A. Todd, artbb@cunyvm.cuny.edu.
ABSTRACT: [Joint work with S. U. Raczkowski and F. J. Trigos-Arrieta.]
(1) Every infinite, Abelian compact (Hausdorff) group $K$ admits $2\sp
{|K|}$-many dense, non-Haar-measurable subgroups of cardinality $|K|$.
When $K$ is nonmetrizable, these may be chosen to be pseudocompact.
(2) Every infinite Abelian group $G$ admits a family $\cal A$ of
$2\sp{2\sp{|G|}}$-many pairwise nonhomeomorphic totally bounded group
topologies such that no nontrivial sequence in $G$ converges in any of
$\cal T\in A$. (For some $G$ one may arrange $w(G,{\cal T})<2\sp{|G|}$ for
the topologies some $\cal T\in A$.)
(3) Every infinite Abelian group $G$ admits a family $\cal B$ of $2\sp{2
\sp{|G|}}$-many pairwise nonhomeomorphic totally bounded group topologies,
with $w(G,{\cal T})=2\sp{|G|}$ for all $\cal T\in B$, such that some fixed
faithfully indexed sequence in $G$ converges to $0_G$ in each $\cal T\in
B$.
For more information, contact:
CCNY (212-650-5346): R. Kopperman
College of Staten Island
(718-982-3626): P. R. Misra
Baruch College (212-387-1463): A. Todd
LIU C.
W. Post Center (516-299-2447): S. Andima
Marymount College (914-631-3200): M.
Hastings
Queens College, Math. (718-997-5849): G. Itzkowitz
Queens
College, Comp. Sci. (718-997-3478): T. Y. Kong