Is it permissible for a person to take ancient artifacts they find in land that does not belong to them, and is that considered theft, knowing that these artifacts are underground and do not specifically belong to the landowner?

These artifacts are either from the pre-Islamic era (Jahiliyyah) or from the Islamic era. If they are from the pre-Islamic era, they are considered rikaz (buried treasure). Scholars differ on whether its ruling dictates it belongs to the owner of the land or to the finder. The more preponderant opinion is that it belongs to the finder, unless the owner claims it. However, if they are from the Islamic eras, or if there is doubt regarding their era, then their ruling is that of luqatah (found property). If a person finds them having entered the land without the owner's permission, some say that they belong to him despite his trespass.