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In this answer to a question concerning the intersection of the future light cone of one event, and the past light cone of another event it was noted that the name

radar bubble suggests itself

for referring to such an intersection (at least if this intersection is not the empty set, if the two events under consideration have accordingly a suitable causal relation to each other).

A plain web search for "radar bubble" along with "intersection" and "light cone" suggests that this terminology is used only rarely (at present; while, surely, such intersections are discussed more frequently).

Therefore my question:
Do we perhaps have another, more conventional name for referring to the intersection of the future light cone of one event, and the past light cone of another event (in suitable causal relation to the first event) ?

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  • $\begingroup$ It is sometimes referred to as the causal diamond due to its shape in two dimensions $\endgroup$
    – Slereah
    Mar 25, 2017 at 10:33
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    $\begingroup$ @Slereah: "It is sometimes referred to as the causal diamond" -- Perhaps so; but this would not agree with the description of "causal diamond" as "set of all events that lie in both the past of some point {...} and the future of some point", as illustrated here. My question is to name the intersection of two light cones, where "the future light cone of an event is the boundary of its causal future", etc. $\endgroup$
    – user12262
    Mar 25, 2017 at 13:56
  • $\begingroup$ I (OP of linked answer) vote for radar bubble. :-) $\endgroup$ Mar 15, 2018 at 0:11
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    $\begingroup$ @Retarded Potential: "I (OP of linked answer) vote for radar bubble. :-)" –- Alright. However, as user Slereah's comment above illustrates, "radar bubble (of two suitable events)" may easily be confused with "the causal diamond (of these two events)". I prefer to speak of the "ping set (of these two events)", or if applicable, their "ping surface". And I hope that this terminology catches on ... $\endgroup$
    – user12262
    Mar 15, 2018 at 8:36
  • $\begingroup$ That's actually pretty good, other than the obvious problem: that it was thought of by someone other than me. $\endgroup$ Mar 15, 2018 at 18:25

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