[kjkjadksj]

The authors don’t format the pdf, the editor does. Authors probably sent a double spaced word document with figures and tables on another file.

[z2h-a6n]

Not on arXiv (unless I'm much mistaken), which is a preprint server, not a conventional journal.

arXiv accepts various flavors of TeX, or PDFs not produced by TeX [0], and automatically produces PDFs and HTML where possible (e.g. if TeX is submitted). In the case of the example paper under discussion, the authors submitted TeX with PDF figures [1], and the PDF version of the paper was produced by arXiv. The formatting was mainly set by using REVTeX, which is a set of macros for LaTeX intended for American Physical Society journals.

[0] https://info.arxiv.org/help/submit/index.html#formats-for-te... [1] https://arxiv.org/format/2312.12451

[smartmic]

FWIW, I recently learned that it is also possible to produce nice PDF papers with GNU roff (groff), have a look at this example: https://github.com/SudarsonNantha/LinuxConfigs/blob/master/....

[pimlottc]

Looks nice but seems strange to switch from two columns to one column after the first page? Although maybe they’re just trying to demonstrate its capabilities.

[macintux]

W. Richard Stevens (RIP, still hurts) famously used troff for his books.

[cozzyd]

You typically send a .tar.gz of tex files (and, figures, .bbl, etc.) to the journal. And then you typically upload something very similar to the arxiv (I have an arxivify Makefile target for for my papers that handles some arxiv idiosyncrasies like requiring all figures to be in the same folder as the .tex file, and it also clears all the comments; sometimes you can find amusing things in source file comments for some papers).

Some fields may use Word files, but in most of physics you would get laughed at...

It is true that most journals will typically reformat your .tex in a different way than is displayed on the arXiv.

[tonyg]

In computer science, the usual case is that the author fully formats the paper.

[aragilar]

Not only is this wrong about physics/astronomy, I regularly use the arxiv version because the typography is better (e.g. in the published paper an equation is split with part of the equation being at the bottom of one column, and the top of the next, whereas the equation is on one line in the arxiv version).

[frocmlol]

You are very confidently wrong.

In the arxiv you use latex and do everything yourself. There is no editor.

[eigenket]

You are completely wrong. ArXiv doesn't work like that.