A new direction in the study of nonperturbative effects in the light-cone system was suggested. Here the light-cone Hamiltonian is used to obtain numerically for the first time masses and wave functions of mesons directly in the light-cone system. These results show the good agreement between this description and corresponding experimental data.
Effective light quark Lagrangian is obtained in the instant on vacuum with nonzero modes included. The resulting quark Lagrangian is nonlocal NJL type, and contains 4q,6q,...vertices for any number of flavours.
New nonlinear equations for field correlators in the large Nc gluodynamics are derived. Nonperturbative confining correlators are shown to satisfy a system of nonlinear scale-invariant equations. Numerically these results are in agreement with lattice data.
The effective action is derived for the instanton interacting with nonperturbative fields. It was shown that nonperturbative effects affect greatly the "instanton's profile function". This function at large distances is replaced due to these effects by Airy function.
The thermodynamics of a three-dimensional adjoint Higgs model is considered. Also, one obtains symmetry restoration at high temperature which makes it possible to construct the phase diagram of the model completely.
The abelian monopoles in the SU(2) lattice gauge theory were studied.
The field-theoretical analogue to the Aharonov-Bohm effect was studied. It is shown that these effect give rise to a nontrivial interaction of tested charged particles.
It was shown that in QCD2 the screening disappears and confinement is restored as soon as fermions are give the mass.
Some exact results for the spectral density of the Euclidean Dirac operator in QCD are derived.
The einbeinfield formalism was suggested to study the canonical quantization for the systems of relativistic particles.