Just for the sake of completness, I found this article surfing the net :
That's not correct; observing just one arm can still tell you that a GW passed, because the round-trip travel time of light in the arm changes. However, it's much harder to measure that change in round-trip travel time in a single arm, then it is to measure the interference between the light in the two perpendicular arms. So an interferometer detector like LIGO is more sensitive than a single-arm round-trip travel time would be.any obesrver in the x arm observing juts what happens in the x direction would not realize a GW is passing by, the same for any observer in the y arm, only the comparison by a third observer of the X and Y observations can deduct that a GW has passed by
Nothing. By the analogy the paper you linked to makes with cosmological models: as the universe expands, clocks are not affected, only distances are. Similarly, as the GW passes, clocks are not affected, only the lengths of the arms are.what happens to the clocks in the "x" arm of the example?
Because that's an English language statement of the metric given in 2.1 in the paper you cite:Still I remain puzzled by the new question: what happens in general to the clocks placed in the X and Y arms? Why does Ibix say that their pace does not change?