Can co-owners to undivided property sell their interest without the other co-owners knowing about the sell?

Can co-owners to undivided property sell their interest without the other co-owners knowing about the sell?

You used the term "inheritance laws" in the subject, but the topic doesn't appear tp be about inheritance. Whether co-owners of property may act independently in selling their individual ownership interest depends on how the property is titled. If titled as "tenants in common" then each person has a fractional interest in the property and the can sell their portion independently of the other co-owners. So for example if there are 3 tenants-in-common then each person owns a 1/3 interest in the property, and can sell their 1/3 interest as they wish, and the buyer then becomes a new co-owner with the remaining two original owners. But if the property is titled as "joint tenants" then no - all co-owners must agree to the sale, and the entire property is sold as a single unit.