The toric Bertini theorem in arbitrary characteristic

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Diane Maclagan, University of Warwick/IAS

The toric Bertini theorem of Fuchs, Mantova, and Zannier gives conditions for the intersection an irreducible subvariety of a torus with a subtorus to remain irreducible, in characteristic zero. I will discuss joint work with Gandini, Hering, Mohammadi, Rajchgot, Wheeler, and Yu in which we give a different proof of this theorem that removes the characteristic assumption.  The proof surprisingly hinges on better understanding algebraically closed fields containing the field of rational functions in n variables.  An application is a tropical Bertini theorem.