Some years ago, I had to photograph academics doing their thing. I found a print of the job recently, and thought the formula looked interesting. The main protagonist tells me:
“The maths describes the clustering of high points in the density field. At the time, we thought galaxies might form there (in some circumstances, we still do).”
And I watched him write it out, without his having to use a cheat sheet; you don’t become Professor for nothing.
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