-Arc connected spaces
Tom 130 / 2013
Colloquium Mathematicum 130 (2013), 221-240
MSC: Primary 54F15; Secondary 54D05, 54F15, 54H05.
DOI: 10.4064/cm130-2-5
Streszczenie
A space is n-arc connected (n-ac) if any family of no more than n-points are contained in an arc. For graphs the following are equivalent: (i) 7-ac, (ii) n-ac for all n, (iii) continuous injective image of a closed subinterval of the real line, and (iv) one of a finite family of graphs. General continua that are \aleph _0-ac are characterized. The complexity of characterizing n-ac graphs for n=2,3,4,5 is determined to be strictly higher than that of the stated characterization of 7-ac graphs.