I see both of them used in mathematical articles as subjects, for example:
Examples from book Renormalization and effective field theory of Kevin Costello, who is an Irish mathematician.
If we do have a continuum quantum field theory (whatever that is!) we should, in particular, have a low-energy effective field theory for every energy.
We will assume that we have an action functional of the form ...
Thus, the Segal axioms for field theory propose that one assigns a Hilbert space of states to a closed Riemannian manifold of dimension d − 1.
Thus, this theorem allows one to quantize the theory associated to any classical action functional.
Examples from Habilitationsschrift Batalin-Vilkovisky formalism in topological field theory(pdf file) of P. Mnev, who is a Russian mathematician:
We should stress that neither quantum Chern-Simon theory, nor quantum Poisson sigma model are constructed by a perturbative path integral on manifolds with boundary...
We reserve symbol d for the de Rham differential on the source.
The followings are in page 6 of the pdf file above:
The idea of constructing topological quantum field theories via path integrals immediately runs into a number of problems:
(1) ... Instead one can try to define the "perturbative" path integral ...
(2) To apply the stationary phase formula, one needs the critical points of the action to be isolated...
(3) ... One has to prove then that the resulting partition functions are independent on the chosen geometric structure.
(4) ... One has to prove fIniteness (convergence) of the Feynman diagrams...
(5) ... one has to extend the path integral construction of TQFT partition functions
In the sentences above, what do words one and we refer to?
And when should one or we be used?
My ideas motivated by answers:
In abstract or conclusion part of a math article, "we" refers to the author(s). In statement and proof part, "we" creates an atmosphere as if the reader is participating with the author, and is used for the author(s) to really discuss / prove / make use of / assume / ... something (a theorem, an assumption, a condition, ...) in this article.
On the other hand, "one" is more like "anyone" or "whoever", and is used to just state some general cases without details or explanations.