Joint IAS/PU Arithmetic Geometry

Algebraic de Rham Cohomology in Mixed Characteristic

I will discuss new structural properties of the de Rham cohomology of smooth schemes over the ring of Witt vectors. The main technical input is the $F$-gauge structure on crystalline cohomology. First, I will explain the slope obstruction to the injectivity of the de Rham-to-crystalline comparison morphism. This yields a negative answer to a question posed by Esnault–Kisin–Petrov. On the positive side, I will show that the comparison morphism becomes injective when restricted to suitable subspaces defined by slope conditions. Finally, I will illustrate how these techniques allow us to determine the de Rham cohomology modulo torsion for such schemes. This is joint work with Daniel Caro.

Date & Time

April 13, 2026 | 3:30pm – 4:30pm
Add to calendar 04/13/2026 15:30 04/13/2026 16:30 Joint IAS/PU Arithmetic Geometry use-title Topic: Algebraic de Rham Cohomology in Mixed Characteristic Speakers: Marco D'Adezzio, IRMA More: https://www.ias.edu/math/events/joint-iaspu-arithmetic-geometry-50 I will discuss new structural properties of the de Rham cohomology of smooth schemes over the ring of Witt vectors. The main technical input is the $F$-gauge structure on crystalline cohomology. First, I will explain the slope obstruction to the injectivity of the de Rham-to-crystalline comparison morphism. This yields a negative answer to a question posed by Esnault–Kisin–Petrov. On the positive side, I will show that the comparison morphism becomes injective when restricted to suitable subspaces defined by slope conditions. Finally, I will illustrate how these techniques allow us to determine the de Rham cohomology modulo torsion for such schemes. This is joint work with Daniel Caro. Princeton University, Fine Hall 224 a7a99c3d46944b65a08073518d638c23

Location

Princeton University, Fine Hall 224

Speakers

Marco D'Adezzio, IRMA

Event Series

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