Choice of personal pronoun in single-author papers Which personal pronoun is appropriate in single-author papers - 'I' or 'we'? Could the use of 'I' be considered egotistical? Or will the use of 'we' be considered to be grammatically incorrect?
Very rarely is 'I' used in scholarly writing (at least in math and the sciences).  A much more common choice is 'we', as in &quot;the author and the reader&quot;.  For example: &quot;We examine the case when...&quot;
One exception to this rule is if you're writing a memoir or some other sort of &quot;personal piece&quot; for which the identity of the author is particularly relevant.
Now let me quote Paul Halmos (Section 12 of &quot;How to Write Mathematics&quot;):

One aspect of expository style that frequently bothers beginning authors is the use of the editorial &quot;we&quot;, as opposed to the singular &quot;I&quot;, or the neutral &quot;one&quot;. It is in matters like this that common sense is most important.  For what it's worth, I present here my recommendation.
Since the best expository style is the least obtrusive one, I tend nowadays to prefer the neutral approach.  That does not mean using &quot;one&quot; often, or ever; sentences like &quot;one has thus proved that...&quot; are awful. It does mean the complete avoidance of the first person pronouns in either singular or plural. &quot;Since p, it follows that q.&quot; &quot;This implies p.&quot; &quot;An application of p to q yields r.&quot; Most (all ?) mathematical writing is (should be ?) factual; simple declarative statements are the best for communicating facts.
A frequently effective time-saving device is the use of the imperative. &quot;To find p, multiply q by r.&quot; &quot;Given p, put q equal to r.&quot;...
There is nothing wrong with the editorial &quot;we&quot;, but if you like it, do not misuse it.  Let &quot;we&quot; mean &quot;the author and the reader&quot; (or &quot;the lecturer and the audience&quot;).  Thus, it is fine to say &quot;Using Lemma 2 we can generalize Theorem 1&quot;, or &quot;Lemma 3 gives us a technique for proving Theorem 4&quot;.  It is not good to say &quot;Our work on this result was done in 1969&quot; (unless the voice is that of two authors, or more, speaking in unison), and &quot;We thank our wife for her help with the typing&quot; is always bad.
The use of &quot;I&quot;, and especially its overuse, sometimes has a repellent effect, as arrogance or ex-cathedra preaching, and, for that reason, I like to avoid it whenever possible.  In short notes, obviously in personal historical remarks, and perhaps, in essays such as this, it has its place.

You can download the pdf of Halmos' complete essay.