2,348 research outputs found
A locally connected continuum without convergent sequences
We answer a question of Juhasz by constructing under CH an example of a
locally connected continuum without nontrivial convergent sequences.Comment: 6 pages. Reprinted from Topology and its Applications, in press, Jan
van Mill, A locally connected continuum without convergent sequence
A homogeneous space whose complement is rigid
We construct a homogeneous subspace of whose complement is dense
in and rigid. Using the same method, assuming Martin's Axiom, we
also construct a countable dense homogeneous subspace of whose
complement is dense in and rigid.Comment: 9 page
Forbidden rectangles in compacta
We establish negative results about "rectangular" local bases in compacta.
For example, there is no compactum where all points have local bases of cofinal
type \omega x \omega_2. For another, the compactum \beta\omega has no
nontrivially rectangular local bases, and the same is consistently true of
\beta\omega \ \omega: no local base in \beta\omega has cofinal type \kappa x c
if \kappa < m_{\sigma-n-linked} for some n in [1,\omega). Also, CH implies that
every local base in \beta\omega \ \omega has the same cofinal type as one in
\beta\omega.
We also answer a question of Dobrinen and Todorcevic about cofinal types of
ultrafilters: the Fubini square of a filter on \omega always has the same
cofinal type as its Fubini cube. Moreover, the Fubini product of nonprincipal
P-filters on \omega is commutative modulo cofinal equivalence.Comment: 15 page
Sleep, depression and anxiety: an epidemiological perspective
Penninx, B.W.J.H. [Promotor]Hoogendijk, W.J.G. [Promotor]Vogelzangs, N. [Copromotor
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