  The concept of dynamical symmetries is specified for quantum dots under
strong Coulomb blockade. It is shown that the electron cotunneling through
quantum dots may be described in terms of generators of SO(n) or SU(n)
dynamical groups, which characterize the energy spectrum of quantum dots.
Various experimental manifestations of dynamical symmetry in Kondo tunneling
both in equilibrium and out of equilibrium are reviewed. Special attention is
payed to algebraic aspects of dynamical symmetries: various representation of
group generators in terms of Hubbard operators, bosonic and fermionic fields
are described.
