The verb usually associated with this is qaS occur, happen.

(HolQeD 5.1):  Since pegh is also a verb (meaning "keep something secret"), pegh vIttlhegh can also be interpreted as a sentence meaning something like "a proverb keeps things secret," that is, it withholds information rather than being a ready source of answers. To some Klingons, this is a most insightful coincidence.

PUN:

1)  "A reference to Douglas Adams and the number 42. Strange coincidences play a big role in his stories." (SuStel)

2)  "I don't think so.  It seems to me that it's a play on the word fortuitous." (ghunchu'wI')

SEE :

quq     happen simultaneously, be simultaneous (v) [i.e. coincide]

quqtaHvIS wanI'vam raQDaq pawta' qotar qempa'QeH je
At the same time Kotar and the Qempa'keh arrive at the camp. (PB)

(Lieven < MO, 1/08/2018):  For parallel universe, I'd go with 'u' quq, using quq "happen simultaneously, be simultaneous".  quq is okay for parallel (in this sense).  Just as a parallel universe can't exist by itself (there has to be a universe - presumably ours - that it's parallel to), a simultaneous universe can't exist by itself.  [...] For mirror universe, I suggest Dop "be opposite, antithetical, contradictory" [...] If they're not making a real distinction between parallel and mirror (that is, if they're using the words interchangeably), I'd stick with quq.