We consider the formulation of the gravity theory first suggested by Regge and Teitelboim where the space-time is a four-dimensional surface in a flat ten-dimensional space. We investigate a canonical formalism for this theory following the approach suggested by Regge and Teitelboim. Under constructing the canonical formalism we impose additional constraints agreed with the equations of motion. We obtain the exact form of the first-class constraint algebra. We show that this algebra contains four constraints which form a subalgebra (the ideal), and if these constraints are fulfilled, the algebra becomes the constraint algebra of the Arnowitt-Deser-Misner formalism of Einstein's gravity. The reasons for the existence of additional first-class constraints in the canonical formalism are discussed.

Non-strange and strange pentaquaks with hidden charm are considered as diquarkdiquark-antiquark composite systems. Spin and isospin content of such exotic states is discussed and masses are evaluated.

Exotic mesons with hidden strange (ss) and heavy quark pairs (QQ), where Q = c, b, are considered as diquark-antidiquark systems, (Qs)(Qs). Taking into account that these states can recombinate into two-meson ones, we study the interplay of these states in terms of the dispersion relation D-function technique. The classification of exotic mesons is discussed, coefficients for decay modes are given, predictions for new states are presented. The nonet structure for (Qq)(Qq) , (Qs)(Qs) , (Qq)(Qs) -states (q = u, d) is suggested.