Displaying similar documents to “Cylinder problem”

Large continuum, oracles

Saharon Shelah (2010)

Open Mathematics

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Our main theorem is about iterated forcing for making the continuum larger than ℵ2. We present a generalization of [2] which deal with oracles for random, (also for other cases and generalities), by replacing ℵ1,ℵ2 by λ, λ + (starting with λ = λ <λ > ℵ1). Well, we demand absolute c.c.c. So we get, e.g. the continuum is λ + but we can get cov(meagre) = λ and we give some applications. As in non-Cohen oracles [2], it is a “partial” countable support iteration but it is c.c.c. ...

Continuous mappings on continua II

T. Maćkowiak, E. D. Tymchatyn

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CONTENTSIntroduction......................................................................................51. General notion of aposyndesis....................................................62. Relation T for special families......................................................83. Properties of T.............................................................................94. T-aposyndesis in homogeneous continua..................................115. Colocal connectedness and T-aposyndesis...............................136....

Waraszkiewicz spirals revisited

Pavel Pyrih, Benjamin Vejnar (2012)

Fundamenta Mathematicae

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We study compactifications of a ray with remainder a simple closed curve. We give necessary and sufficient conditions for the existence of a bijective (resp. surjective) mapping between two such continua. Using those conditions we present a simple proof of the existence of an uncountable family of plane continua no one of which can be continuously mapped onto any other (the first such family, so called Waraszkiewicz's spirals, was created by Z. Waraszkiewicz in the 1930's).

1/2-Homogeneous hyperspace suspensions

Sergio Macías, Patricia Pellicer-Covarrubias (2012)

Colloquium Mathematicae

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We continue the study of 1/2-homogeneity of the hyperspace suspension of continua. We prove that if X is a decomposable continuum and its hyperspace suspension is 1/2-homogeneous, then X must be continuum chainable. We also characterize 1/2-homogeneity of the hyperspace suspension for several classes of continua, including: continua containing a free arc, atriodic and decomposable continua, and decomposable irreducible continua about a finite set.