1
$\begingroup$

What is an example of a topological space $(X,\tau)$ with the properties that

  1. $X\cong X\setminus \{x\}$ for all $x\in X$, and
  2. $(X,\tau)$ is not topologically homogeneous

?

$\endgroup$

2 Answers 2

8
$\begingroup$

An infinite disjoint union of half-open and open intervals works.

$\endgroup$
1
  • 1
    $\begingroup$ Don't you need infinitely many half-open and infinitely many open intervals? $\endgroup$ Commented Nov 9, 2017 at 11:50
5
$\begingroup$

Take the disjoint union of any two nonhomeomorphic spaces with that property as long as they are perfect, e.g., $\mathbb{Q}\coprod(\mathbb{R}-\mathbb{Q})$.

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .