The inspiration for these questions is the following observation:
In American writing, the German terms "eigenvector" and "eigenvalue" are 
sometimes translated as "characteristic vector" and "characteristic value", but 
those are such mouthfuls that usually the German terms are just borrowed as-
But in British writing, the terms are often translated as "proper vector" 
and "proper value", and these compete favorably with the barely-modified 
German words.


So, here the question:

In what circumstances do UK speakers often use "proper" where a USA 
speaker would use "own"?

Is such usage old-fashioned now in the UK?  Or is it still current in some 

Are such usages limited to just parts of the UK?  For instance, just Great 
Britain? or just England?

Or do they actually also occur in other English-speaking countries?

Does Canadian English more closely resemble UK English or USA English in this 


Thanks in advance to anyone who knows anything about any of these