Are cross posts to Math SE allowed? As in almost exactly the same text, just posted there. Of course the sites are meant for difference things, but still just wondering. And if yes, should one link the MO post before posting on Math SE?
If you have posted a question at MSE and want to cross-post it at MO or the other way around, you can do it under the following conditions:
- Wait several days, not just hours. I would suggest a week.
- Provide links between the two versions. The MO question should have link to the one at MSE and vice versa. (This is for honesty and avoiding duplicate efforts for those who answer.)
- Make sure the question is on-topic at the new site.
- If you have received helpful comments for the old question but no answers, take them into consideration when posting here.
- MO and MSE require different merits for questions to be well-received. Not only are the scopes different, but also the communities value different kinds of background information.
These conditions reflect what I believe to be a consensus of some kind, but some people might disagree.
I think you should not cross-post instantaneously. If you realized that you asked in the wrong place and there are no answers yet, simply delete the old one and ask in the right place.