6 problems

Finite-basis conjecture. There exists a finite set of differential invariants such that every differential invariant of $G$ can be represented as a function of these invariants and…

Let a Lie pseudogroup $\Gamma$ act on a differential equation $E\subset J^kq$, and let the associated quotient relative algebroid and its prolongation tower be given. Consider the…

A differential invariant $I$ is of Schwarzian type when, for every diffeomorphism $\phi$, its pull-back satisfies … where $S(\phi)$ is the Schwarzian derivative. The relevant dicho…

A differential invariant $I$ is of Schwarzian type when, for every diffeomorphism $\phi$, its pull-back satisfies … where $S(\phi)$ is the Schwarzian derivative. Differential invar…

The paper studies immersed curves in Cartan geometries, using Cartan's method of moving frames to construct differential invariants and solve equivalence problems. Cartan-geometry…

Second-prolongation invariant-count conjecture. For any value $n$ of independent variables, the number of functionally independent invariants of the second prolongation of $G$ is