3 papers
math.AG2025
Deformation to the normal bundle and blow-ups via derived Weil restrictions
Jeroen Hekking, Adeel A. Khan, David Rydh
We develop an analogue of the deformation to the normal cone in the context of derived algebraic geometry. This provides any given morphism of derived stacks with a degeneration to…
math.AG2025
The étale local structure of algebraic stacks
Jarod Alper, Jack Hall, David Rydh
We prove that an algebraic stack with affine stabilizers over an arbitrary base is étale-locally a quotient stack around any point with a linearly reductive stabilizer. This gener…
math.AG2025
Functorial flatification of proper morphisms
David Rydh
For proper morphisms, we give a functorial flatification algorithm by blow-ups in the spirit of Hironaka's flatification algorithm. In characteristic zero, this gives functorial fl…