Acknowledgement in papers I have helped a scientific(math) author to find a reference and I have corrected several errors in his paper. Should he acknowledges me when he publishes his paper? Will that affect my academic career positively or negatively? And if he doesn't acknowledge me what can I do?
should he acknowledges me when he publish his paper? 


Acknowledgments are discretionary, so they needn't acknowledge you.


  Will that affect my academic career positively or negatively? 


Any impact will likely be minimal.


  And if he doesn't acknowledge me what can I do? 


You needn't do anything.