El próximo mes de abril tendrá lugar el Kunen Fest en la Universidad de Wisconsin, en Madison. Será todo un festival de charlas de antiguos estudiantes de Ken Kunen y de colegas suyos (incluidos Keisler y Todorcevic). Dos lógicos bogotanos tuvimos la suerte de ser alumnos doctorales de Kunen.

Unas frases de la invitación al evento:

Coloquio - Departamento de Matemáticas - Universidad Nacional

Lunes 16 de febrero - 4 pm
Edificio 405 Salón 202

Cardinal invariants of the continuum

Joerg Brendle - Universidad de Kobe (Japón)

Abstract: Cardinal invariants of the continuum are cardinal numbers which describe the combinatorial structure of the real line. Most of them assume values between the first uncountable cardinal aleph_1 and the cardinality of the continuum. Much of the motivation for studying such cardinals comes from problems in general topology, group theory etc. However, because of their strong interplay with forcing theory, they are also of intrinsic interest in set theory.

Most classical cardinal invariants are defined in terms of P(N) / fin (the quotient of the subsets of the natural numbers N by the finite sets), but recently cardinal invariants defined in terms of related structures have been investigated as well. For example, there is ongoing work on invariants related to P(C(H)), the collection of projections in the Calkin algebra C(H) (the quotient of the bounded operators on a separable Hilbert space by the compact operators).

In this talk, I will define some of the cardinal invariants, both for P(N) / fin and for P(C(H)), prove some basic results, and mention recent developments and open problems.

Los próximos 5 y 6 de febrero tendremos las Jornadas colombo-venezolanas de teoría de conjuntos organizadas por la Universidad Nacional  y la Universidad de los Andes. Click aquí para más información.

Next February 5th and 6th will be the Colombia-Venezuela Set Theory days, an event hosted by Universidad Nacional and Universidad de los Andes in Bogotá. Click here for more detailed info.