Your question is currently extremely unclear (potentially because you're over-relying on unreliable machine translation?), but the three initial versions of the text contain some kind of version of the following,
In my view there is no homogeneity of views between one site and another.
Why is there no coherence between the two web-sites?
as well as the (currently utterly unclear)
But some users of Mathematics.SE ask me, instead, to write questions about physics, although they contain mathematical aspects, that they are not welcome on the site Physics.SE. Why?
and, while this might not reflect what you actually wanted to ask, there's enough here to address a key point:
- There is no requirement of a cohesive policy between the Physics and Mathematics sites.
They are run by separate communities, serving different audiences for different topics and in different environments, with vastly different histories. We're bound by the (very loose) framework of the Stack Exchange ethos and overall rules, but anything above and beyond that is a bonus. In particular, this means that the fact that a certain type of question is on-topic at the Maths site does not guarantee that it will be on-topic here, or vice versa.
There also isn't a clear delimiting line that says "questions on this side go to Physics and questions on this side go to Maths", in any shape or form. Some questions might be on-topic on both sides, while some questions might not be on-topic on either site. In other words: "this question is too physicsy for Maths SE" does not guarantee that it will be on-topic on Physics, or vice versa. If that's what's bothering you, then I'm sorry, but this site does not aim to be all things to all people, and it's entirely possible that we're not what you're looking for, and that you'll need to find that elsewhere.
Now, it can happen that someone on Physics will tell you something like
this question is too mathsy for Physics SE, you should try asking it on the Maths site
but that your question then gets a bad reception on Maths. (Let's leave aside, for now, the (entirely real) possibility that the bad reception is due to, say, a bad use of language on your part.) If this is the case, you should not interpret those comments on PSE as being "guarantees" that MSE will work out: instead, they're clear indicators that the question is too mathsy for our scope, but (unless the user in question is demonstrably a frequent user of MSE) only tentative pointers of other places to try. And again: the fact that it's too mathsy for PSE does not guarantee, in any way, that it will be on-topic at Maths.
And finally: Language Matters. If your questions use unclear language, then they are more likely to be closed as Unclear What You're Asking, and they are more likely to be downvoted.
- We close unclear questions because they direct answerer attention from other questions which do provide sufficient clarity to have unambiguous answers.
- We downvote unclear questions because they are not useful to future visitors, so they should be ranked lower when search results are presented.
Those are core, integral parts of how the SE Q&A engine works, and they're one of the key reasons why SE shines in providing good-quality content. If these aspects bother you, then you should look for other platforms that don't have content quality as a key tenet.
The same holds for text that is not in English: the language of this site is English, and including crucial parts of your question in other languages is going to lead to a bad reception, from downvotes to closevotes to comments telling you not to do that. If you want to avoid that bad reception, then post only in English, and only include other languages when absolutely crucial and accompanied with a suitable, high-quality translation. To be clear: machine translation is generally not of sufficient quality to be posted directly, particularly on technical subjects like physics. You are responsible for the clarity of the language that you post here, and if it's unclear enough to merit downvotes or closevotes, then edit it to clarify it, or accept the response. Downvotes are not a personal indictment against you, they are indicators about the content of the post.
Similarly, on this site there is a very strong consensus that screenshots of text are off-limits here, which means that posts with such screenshots are similarly subject to a bad reception. If you don't want that bad reception, then follow the site consensus.
And finally: same as with Maths SE, there is no requirement of a cohesive policy with TeX SE. Some things might fly on TeX SE that are not OK here -- in which case, good for TeX SE! but that still doesn't mean that they can fly here. Your text might be clearer on TeX SE (where posts are generally aided by the fact that they contain code, which is much more unambiguous that technical text on physics), but that doesn't mean that text of similar quality passes the standard clarity bar here.