Local path-connectedness v. path-connectedness

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Discussion Overview

The discussion centers around the relationship between path-connectedness and local path-connectedness in topological spaces. Participants explore whether a space can be path-connected while not being locally path-connected, examining definitions and providing examples.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant questions if a space can be path-connected and not locally path-connected, expressing initial intuition against this possibility.
  • Another participant references a website that appears to contradict the initial intuition, suggesting that the topic may warrant further exploration.
  • A request for clarification on the definition of local path-connectedness (lcp) is made, indicating a need for precise terminology.
  • A definition of local path-connectedness is provided, stating that every neighborhood of a point contains a path-connected neighborhood.
  • An example is proposed involving a space formed by the union of the y-axis, the x-axis, and horizontal lines at ordinates y = 1/n, which is suggested to be path-connected but not locally path-connected at most points on the x-axis.
  • A participant acknowledges the example as a valid illustration of the concept, indicating a shift in their understanding.

Areas of Agreement / Disagreement

Participants do not reach a consensus; there are competing views regarding the relationship between path-connectedness and local path-connectedness, with examples provided that challenge initial intuitions.

Contextual Notes

Some definitions and examples may depend on specific interpretations of topological concepts, and the discussion includes unresolved assumptions about the nature of the spaces being considered.

cogito²
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Can a space be path-connected and not locally path-connected? (To be clear, "locally path-connected" just means that there is a basis of path-connected of sets.)

My general intuition says no, but my intuition seems to usually be wrong...and this would explain why Hatcher keeps referring to spaces that are both p.c. and l.p.c. in his Algebraic Topology...
 
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My first time around google didn't bring me to this site which claims to contradict my intuition. So I guess this thread can be ignored...
 
what is the definition of lcp?
 
well planet maths ays lcp means every nbhd of p conrtains a pc nbhd.

so just take any silly space like say the union of the y axis, the x-axis and the horizontal lines at ordinates y = 1/n.

thAT SHOULD BE PATH CONNECTED AND NOT LOCALLY SO at any point of the x-axis except (0,0).
 
That's a pretty nice example of such a space.

Well I guess it's time to fine-tune my intuition...
 

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