1
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0answers
146 views

Fields over which cubic hypersurfaces are rational

All cubic hypersurfaces having at least one double point are birational to some $P^n$ over an algebraically closed field. How does the statement change as I pass to non alg closed fields? Does it hold ...
5
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1answer
343 views

is Hasse principle a birational invariant?

...it is probably a very trivial question, but I am a beginner in arithmetics.