I am a math PhD student in a foreign country. When finishing my papers, my advisor (who is a big name in the field) always proposes me to submit them to a journal. The problem is that so far none of these have been top-tier journals. On the other hand, in my mind, there is no doubt that the results are good enough to be published in really good ones, and I have also confirmed this fact after giving talks at conferences. In addition, in one of these papers, he/she was signed as a corresponding author, even when I did 99% of the job. Why would someone do this to his/her student?
First of all, journal quality is not an objective thing (measures like acceptance rate and impact factor and so on really do not mean that much, and can be gamed). There isn't necessarily universal agreement about which journals are "top-tier". So consider the possibility that your supervisor simply has a different opinion about the reputation of these journals than you do.
The advisor does have a responsibility to give advice that they believe will be beneficial to students, including advice about where to publish. (Of course, the student also has a responsibility to educate themselves about publication options as best they can, ask questions to try to understand the advisor's suggestions, and speak up if they disagree.) I'm not sure what you mean about whether it is in the advisor's "best interest". It is not like they will get paid more if you publish in Acta, but it does generally reflect well on an advisor if their students are successful.
But there is a serious trade-off of submitting to top journals: time to acceptance. The peer review process in math is much slower than in many other fields, and top journals are very selective. Even if your paper is "good enough" for a top journal, that doesn't mean that it will be accepted by the first one you submit to, and it may be under review for several months before being rejected. Then you have to start over. As a PhD student, you really want to have papers accepted before you begin to apply for postdocs or other jobs. A paper that hasn't been accepted anywhere, even if it's an awesome paper, doesn't help your job prospects much, because there's no independent confirmation that it's awesome.
So at this particular stage of your career, it could be very sensible to submit your work to a less-than-top journal, even if you think it has a chance to be accepted somewhere better, because it's more important to get it accepted fast, without having to go through several submit/review/reject cycles with different journals. This is something your advisor ought to take into account when suggesting journals. But it's a balancing act between the considerations of "publish in the best possible place" and "get accepted on the first try", and you should of course speak up if you have a different opinion about how to balance those.
(If your advisor is a co-author, this same balancing act could apply to them as well. For instance, they might have a promotion decision coming up, and they want to have the paper accepted somewhere before that happens. Sometimes different authors may have conflicting needs in this regard, and they have to reach agreement somehow. Personally I think that the needs of more junior authors, such as PhD students, ought to be weighted more heavily, but that is just me.)
I also want to comment on the "corresponding author" question. People around the world seem to have different opinions about what it means to be corresponding author. In my part of the world (US), it's my impression that being corresponding author only means what it says: this is the author who corresponded with the journal (sent in the submission, filled out the forms, etc), and who is the best person for a reader to reach if they have questions about the paper. Around here, it doesn't carry any particular prestige, and it isn't meant to imply that "this person did most of the work". So on that basis, I wouldn't say that there was anything wrong with your advisor being corresponding author. (For one thing, your advisor probably has a more stable email address, since you are going to graduate before too long.) There may be some benefit to being corresponding author as a student, just to get practice with the journal submission process, but it's not really a reputation benefit.
(If "corresponding author" has a different connotation among people in your part of the world, or more importantly, the part of the world where you intend to apply for postdocs, then the previous paragraph may not apply to you.)
Is in the best interest of supervisors that his/her students publish their research results in Top journals?
All other things being equal, of course it is.
in my mind, there is no doubt that the results are good enough to be published in really good ones
With all due respect, I am willing to bet that your sense about these things isn’t nearly as well-calibrated as your advisor’s. Unless you already had several papers accepted at top math journals, the fact there is no doubt in your mind is essentially meaningless.
To be clear, I’m not saying you are necessarily wrong, just that your confidence is very likely misguided, even if you got great feedback about your work at conferences. Talk at conferences is cheap; referee reports recommending acceptance in a top journal are a much more rare kind of feedback.
Why would someone do this to his/her student?
There isn’t a rational reason why an adviser would want their students to intentionally undersell their achievements by submitting to a lower-tier journal than the paper is suited for. The (overwhelmingly) most likely explanation is that your adviser is giving you the best career advice she can, and simply does not think your papers have a high chance of being accepted in a top journal. Keep in mind that there is nothing offensive or negative about having such a belief; she may well think your papers are excellent but still have a more nuanced understanding than you of how few even excellent paper are groundbreaking and competitive enough to get accepted in a top journal.
As for the timing issue that Nate brings up in his answer, I think that could factor to a minor extent in the advice your adviser is giving you, but probably if she thought your papers were good enough for a top journal but thought submitting there might be risky because of the time delay this might incur, she would explain to you the considerations, tell you her opinion about the odds, and let you make the final decision yourself. So I’m guessing that’s not the main issue here.
Well, ask her how your advisor chooses the journals she wants you to submit. You can also include your past articles in this question. I am pretty sure you will learn from the answer.
Some reasons for how to choose a journal:
- Better fit: Even if you could publish in Nature or Science, research about quantum optics might be better suited to some journal on quantum optics. Your peers won't read Nature or Science anyway.
- Acceptance rate: Some journals receive way to many articles. This creates extra work if you have to resubmit to another journal.
- Quality of review: Good reviews helps to improve a paper. You as a young researcher will profit from a thorough and constructive feedback. Sketchy or harsh review does help your writing and research.
- Time to publication: If it is short, you will profit more from the earlier publication compared to the more prestigious journal. Especially as a PhD candidate this is in your interest.
- Costs: In many cases a publication costs money, e.g., for color figures, too many pages or to make it open access. Your advisor might know this and want to save money.
- Politics: They might want to support some group, they are friend to or disliked by a specific journal.
Why would someone do this to his/her student?
You're assuming bad faith. While that is not impossible it's also less likely than a failure of communication between you two.
You should tell your advisor you want to talk to her about the issue of choosing targets for publication. Tell her that you'd like her to tell you about:
- The strategies different researchers in your field employ.
- Her strategy - for graduate students, and perhaps even for her publications without grads.
At this meeting, after being given an explanation of the general policy/strategy - ask her something like "Ok, so I want to apply this as a thought experiment to some of the papers we co-wrote. Let's take paper Foo. etc. etc. etc. [try to explain how the strategy should have applied to your paper here ]. Does that sound reasonable?" ... and with this you've asked her to justify her recommendations on (one of) your papers in a rather non-confrontational way. Since your description ends up with a submission to different journals than the one she had suggested.