Better than that, it has been imaged. We know it is there. It seems to have some influence or control in what and where normal baryonic matter is. We know that it is the real show not us, that it predominates and that matter likely wholly DEPENDS on and is determined by it! Other than that, we have no idea the relationship nor can we otherwise affect it, but likely, without an understanding of what dark matter is, we will never understand neither gravity itself nor what created or maintains the cosmos; dark matter would appear to be the key.