Folded solitary waves and foldons in (2+1) dimensions

A general type of localized excitations, folded solitary waves and foldons, is defined and studied both analytically and graphically. The folded solitary waves and foldons may be "folded" in quite complicated ways and possess quite rich structures and abundant interaction properties. The folded phenomenon is quite universal in the real natural world. The folded solitary waves and foldons are obtained from a quite universal formula and the universal formula is valid for some quite universal (2+1)-dimensional physical models. The "universal" formula is also extended to a more general form with many more independent arbitrary functions.