Etiquette when continuing work on a research direction without involving former collaborators I have collaborated on a certain topic with researchers A, B and C, where A is my PhD supervisor (I'm now a post-doc), and B and C are senior colleagues from different universities. The collaboration lead to a number of papers, in which I was the main author, while A, B and C made important contributions.

I'm now working on an idea that continues the research direction of this earlier work. Since I already got pretty far with the execution of my idea, I don't expect much additional benefit from involving A-C at this stage. In fact, I would prefer to publish this work without them, since I'm in a career stage where the common advice is to assert myself as an independent researcher.

However, I have the feeling that A-C might be disappointed if I don't involve them - I certainly would, if I was in their position. Is there an etiquette for tactfully dealing with this kind of situation?
If you have a feeling that you will disappoint them then, by all means, let them know! And indeed, you should let them know that you've continued this line of research independently.

You can phrase your invitation in a way that it hints that you would like to go on alone. Something like


  Lately, I was working independently on extensions regarding our previous work and I went pretty far and I have such-and-such results. I believe that these results are interesting enough to make a publication. I would like your opinion about this and about potential venues that would accept this paper.


By this, you make clear that this is your work, you acknowledge their expertise and definitely you give them a heads up. This is actually quite common and I expect them to either ignore it (if they are busy) or be happy that you were able to generalize it and give you valuable hints/advice.