politely refusing authorship opportunity? I (a grad student) first-authored a paper with my ex-PI and some colleagues. The paper was rejected from a journal. Meanwhile, this ex-PI also bullied me, did something else that was hurtful, and did not provide helpful feedback on the paper.  The ex-PI is now asking if I want to re-submit.  Can I politely refuse? If so, how?
They’re an ex-PI and one that you’ve had negative experiences with. Still, networking and connections, even if faint, can come back and be helpful directly or indirectly. Diplomacy is key. Give your appreciation for their interest in collaborating, but decline, citing other obligations, time commitments, etc.