3 papers
math.AG2026
A note on complex Lie Algebras isomorphic to their conjugate
Cyril Demarche
A real Lie algebra defines by extension of scalars a complex Lie algebra that is isomorphic to its Galois conjugate. In this paper, we are interested in the converse property: give…
math.NT2026
Lifting Galois representations via Kummer flags
Andrea Conti, Cyril Demarche, Mathieu Florence
Let be either i) the absolute Galois group of a local field , or ii) the topological fundamental group of a closed connected orientable surface of genus . In case i), as…
math.AG2025
Degree 4 cohomological invariants of algebraic tori
Cyril Demarche, Hanqing Long
In this paper, we determine the motive of the classifying torsor of an algebraic torus. As a result, we give an exact sequence describing the degree 4 cohomological invariants of a…