This is perhaps a soft question.
Let $X=\mathbb{S}^1 \times \mathbb{S}^1$. Let $\mathbb{Z}_2$ act on $X$ by setting $(-1) \cdot (\theta,\psi)=(\theta+\pi,\psi+\pi)$. Consider the quotient space $X/ \mathbb{Z}_2$ which is obtained after identifying $ (\theta,\psi) \sim(\theta+\pi,\psi+\pi)$.
Is there a succinct description of $X/ \mathbb{Z}_2$ as some product or twisted/fibered product or something like that?
Are there other "simple" descriptions of this space? Is it related to some projective space?
I feel like there should be a "right" terminology to describe it, or a way to recognize it as some familiar space, but I fail to see it.
I understand that identifying antipodal points on the $2$-torus embedded in $\mathbb{R}^3$ results in a Klein bottle- but this is not the same identification we are doing here:
Here we identify $(\theta,\psi)=(\theta+\pi,\psi+\pi)$, and in the embedded description we identify $(\theta,\psi)=(\theta+\pi,-\psi)$.
from Hot Weekly Questions - Mathematics Stack Exchange
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