Path space and cofibration in topological spaces

51 Views Asked by At

This question came to me while reading "Model Categories and their Localization", specifically the definition of path object in a general model category.

Given a topological space $X$, we have a homotopy equivalence $c:X\rightarrow X^I$, where $X^I$ is the space of maps $I=[0,1]\rightarrow X$, sending a point $x$ to the constant path with value $x$. I think $c$ is not a cofibration (in general) and I tried to prove it by showing that $c$ doesn't have the homotopy extension property, since it is a characterization of cofibrations, but haven't made much progress in this direction. Any hint or reference on whether or not my claim is true would be greatly appreciated.

A related question, if the above claim ($c$ is not a cofibration) is true, would be: Is there a characterization of those spaces $X$ such that $c$ is indeed a cofibration? Discrete spaces satisfy the condition, since $X^I$ is homeomorphic via $c$ to $X$ itself, are these the only ones?