Typo `\dots`

[j-horner-c4x]

theoretical-physics/src/quantum/dft.rst

Line 46 in e5b5382

electron at the position $\bf r_1$, the second at $\bf r_2$, \dots and the Nth

Missed $ I think so \dots just appears as "dots" in the text.

[certik]

Great catch! Thanks! If you could please submit a PR to fix this, that would be very helpful.