Mar 10 2025

Algebraic Geometry Seminar: Cubic fourfolds with birational Fano varieties of lines, by Lisa Marquand

March 10, 2025

3:00 PM - 3:50 PM

Location

636 SEO

Address

Chicago, IL

Lisa Marquand (New York University): Cubic fourfolds with birational Fano varieties of lines

Cubic fourfolds have been classically studied up to birational
equivalence, with an eye towards rationality problems. On the
other hand, the Fano variety of lines F(X) on a cubic fourfold X
is a hyperkahler manifold, and the rationality/irrationality of
X is conjecturely reflected in the geometry of the Fano variety
of lines.  We give examples of conjecturally irrational cubic
fourfolds with birationally equivalent Fano varieties of lines.
Two of our examples, which are special families in C_12, provide
new examples of pairs of cubic fourfolds with equivalent Kuznetsov
components. Further, we show the cubic fourfolds themselves are
birational. Our examples were discovered by studying the group of
birational transformations of the Fano varieties of lines of these
cubic fourfolds. This is joint work with Corey Brooke and Sarah Frei,
building on our previous work with Xuqiang Qin. 

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Contact

Philip Engel

Date posted

Mar 5, 2025

Date updated

Mar 5, 2025

Speakers