Can a non-signatory party to an arbitration agreement be bound to arbitrate?

there are six theories by which a nonsignatory may be bound to arbitrate: (a) incorporation by reference; (b) assumption; (c) agency; (d) veil-piercing or alter ego; (e) estoppel; and (f) third-party beneficiary " (Suh v. Superior Court (2010) 181 Cal.App.4th 1504, 1513, 105 Cal.Rptr.3d 585.)⁵ "These exceptions to the general rule that one must be a party to an arbitration agreement to invoke it or be bound by it generally are based on the existence of a relationship between the nonsignatory and the signatory, such as principal and agent or employer and employee, where a sufficient "identity of interest" exists between them. " (DMS, supra, 205 Cal.App.4th at p. 1353, 140 Cal.Rptr.3d 896.)