2 citations · 2 across the 3 of their papers we have counts for
3 papers · 1 filter
Spencer delta-cohomology, restrictions, characteristics and involutive symbolic PDEs
Boris Kruglikov, Valentin Lychagin
We generalize the notion of involutivity to systems of differential equations of different orders and show that the classical results due to Guillemin and Quillen relating involuti…
On the Blaschke conjecture for 3-webs
Vladislav V. Goldberg, Valentin V. Lychagin
We find relative differential invariants of orders eight and nine for a planar nonparallelizable 3-web such that their vanishing is necessary and sufficient for a 3-web to be linea…
Linearizability of d-webs, d \geq 4, on two-dimensional manifolds
Maks A. Akivis, Vladislav V. Goldberg, Valentin V. Lychagin
We find d - 2 relative differential invariants for a d-web, d \geq 4, on a two-dimensional manifold and prove that their vanishing is necessary and sufficient for a d-web to be lin…