# How to publish two interdependent papers

I have two finished articles (each about 25 pages long) but the second one uses results from the first one, none of which has been published yet. I would like to send them to some standard journal for consideration but I do not know exactly how to do so. Should I put them up on arxiv, refer back to the first article for the relevent results and send them to the respective journals? Or should I send one at a time? I do not know if this is the right place to ask this question, but I really wanted to get some professional opinion.

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"Should I put them up on arxiv" yes, independently of the context. Anyway, academia.stackexchange.com is probably better suited for such questions. –  darij grinberg May 5 at 16:54
This is not a big deal. As long as both preprints are publicly available (preferably on the arXiv), it is totally normal to have logical dependencies between them. Just submit them in the normal fashion. If I were the referee of the second one, I would probably take a look at the first and make sure I believed it before I recommended accepting the second one, but I wouldn't bat an eye about it. Sometimes you can't even control things, e.g. if you have a paper that depends on a theorem of someone else and it takes a long time for them to publish it. –  Andy Putman May 5 at 18:07
I'm not experienced with publishing papers, but is there a good reason you shouldn't combine them into one paper? –  Kevin May 5 at 20:15
I am currently in a similar situation (except worse... 2x60 pages) and have been explicitly advised by several people to not combine them (actually the two papers used to be one and I have been advised to split it in two). –  darij grinberg May 5 at 20:28
@Kevin : The longer a paper is, the harder it is to publish in a decent journal. I think that a good strategy when trying to figure out how to split up results into papers is to try to maximize the $L^{\infty}$ norm of the journals that they will end up in (notice that this is very different from maximizing the number of papers!). –  Andy Putman May 6 at 2:07

Put both papers in the arxiv. Have the second cite the first, if it depends on the first. You may have the first cite the second as a "preprint" as a motivation, if it's useful. This can be updated by re-posting the first paper once you know the "coordinates" (arxiv number) of the second.

If the papers form a clear sequence, you may wish to submit both papers together to the same journal. Explain why you are submitting two papers and their relation to each other in the cover letter. Otherwise submit them separately.

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This situation frequently happens. In the era before the arxiv, I usually submitted such a pair of papers in one journal (simultaneously) and indicated which should be published first. In the second paper I would make the reference on the first one (calling it a preprint). The purpose of this is that very likely they will go to the same referee.

Arxiv makes the things simpler, because a reference to arxiv is a legitimate reference, and this gives you flexibility to send them to different journals, if you prefer. This may be a reasonable option if you want them to be published as soon as possible. Some journals are reluctant to publish two papers of the same author in a short sequence.

Posting all your papers on arxive has a lot of advantages. One of them is that you secure your priority, can put them on your vita and grant reports, and don't have to care how long will the journal publication take.

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If they are so long, you could also consider to compile them into one to prepare a small monograph. Of course, it depends on the content.

Such monograph could be published in e.g. Dissertationes Mathematicae.

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