Local selections and local dendrites |
| |
Authors: | LE Ward |
| |
Institution: | University of Oregon, Eugene, OR 97403, USA |
| |
Abstract: | Let X be a Peano continuum, C(X) its space of subcontinua, and C(X, ε) the space of subcontinua of diameter less than ε. A selection on some subspace of C(X) is a continuous choice function; the selection σ is rigid if σ(A) ? B ? A implies σ(A) = σ(B). It is shown that X is a local dendrite (contains at most one simple closed curve) if and only if there exists ε > 0 such that C(X, ε) admits a selection (rigid selection). Further, C(X) admits a local selection at the subcontinuum A if and only if A has a neighborhood (relative to the space C(X)) which contains no cyclic local dendrite; moreover, that local selection may be chosen to be a constant. |
| |
Keywords: | Primary 54C65 54B20 Secondary 54F50 54F25 |
本文献已被 ScienceDirect 等数据库收录! |
|