There are other similar nice passages about the sort of math that the researchers at the institute were doing.

The entire story is narrated by the investigating detective, one of the few characters who is not a mathematician.

And, the detective realizes that unlike the cases he is used to (where one must think about sex or money to identify the killer), in this case math is probably the motive:

Indeed, although lots of the researchers at the institute have mathematical models to predict the dynamics of Hyperion, the main suspect in the crime is the author of the model that seems to be too accurate.

Two other major themes in the story are sex and music. Every female character seems to be assessed as a potential sex partner by the narrator, and he does seem to have sex with nearly all of them. The open and frequent sex between residents of the institute is presented as part of a utopian experiment towards a more peaceful future for humanity. It becomes just a bit mathematical when the connections between different individuals that is being optimized is described as a "correlation matrix". Music comes up because one of the main characters is interested in both listening to and composing classical music. This also becomes linked to the math in the story when (not very convincing) musical analogies are used to compare the predictions of some real algorithms modeling the dynamics of the moon with those of the suspiciously accurate model.

As you surely know if you've read many of my posts on this website, I try to address common stereotypes of mathematicians which appear in fiction. With that in mind, it is worth noting that several of the characters in the story are female mathematicians who are portrayed as being very intelligent. (A male character who is not a mathematician says to our detective "These brilliant women are a bit addicting. I'm not sure if I'd know what to do around an airhead anymore.") They are all at least a bit quirky and there are suggestions that at least one of them is (technically) "insane":

As I said, I really liked the mathematics in this short story. Neither the resolution of the mystery nor the climax of the story were particularly mathematical. So, I won't say anything more about them except to note that (IMHO) the ending was "meh".

This story "A Calendar of Chaos" appeared in the December 1991 issue of Analog Science Fiction & Fact. (A sequel entitled"Relic of Chaos" was published in 2001. It featured some of the same characters and had the word "chaos" in its title, but I didn't see any math in it.)

Thanks to frequent site contributor Fred Galvin for letting me know about this story after seeing it discussed on StackExchange.