Hello, I apologize for the inconvenience, but I have checked and the heat equation tutorial works correctly in parallel on my computer. The problem arises from the fact that in the code I used, I added a few extra lines to solve another PDE on a submesh of the parent mesh.
I defined my submesh as follows:
submesh, entity_map, _, _ = dolfinx.mesh.create_submesh(mesh, mesh.topology.dim, cell_tags.indices[(cell_tags.values==1)])
Does the create_submesh function work in parallel now, or would it be better to use MeshView as indicated in this post Use of Submesh in parallel - #2 by dokken ? In that case, I don’t understand how my code could work for 2 processes and not more.
Thank you in advance.