  It is now widely believed that if the gravitational field is (perturbatively)
quantum, it would entangle two massive objects (in spatial superpositions)
which were otherwise unentangled to begin with. Recently, actual table-top
experiments have been proposed to test this idea in what would be the first
detection of perturbative quantum gravity. In this essay, we devise a thought
experiment to prove that such gravity-induced entanglement depends on the
spacetime curvature and can, in principle, act as an alternate signature of the
expanding background. This will open up new and complementary directions to
search for such entanglement in curved spacetime and reveal fresh perspectives
on it.
