Matrix at strong coupling

We describe the strong coupling limit (g->infty) for the Yang--Mills type matrix models. In this limit the dynamics of the model is reduced to one of the diagonal components which is characterized by a linearly confining potential. We also shortly discuss the case of the pure Yang--Mills model in more than one dimension.Comment: 15 pages, text improved, misprints corrected, a comment and new references adde

M[any] Vacua of IIB

Description of the spectrum of fluctuations around a commutative vacuum solution, as well as around a solution with degenerate commutator in IIB matrix model is given in terms of supersymmetric Yang-Mills (YM) model. We construct explicitly the map from Hermitian matrices to YM fields and study the dependence of the spectrum and respective YM model on the symmetries of the solution. The gauge algebra of the YM model is shown to contain local reparameterisation algebra as well as Virasoro one.Comment: 17 pages, Virasoro algebra explicitely given, LaTeX style change, minor text change

On the dynamics of BMN operators of finite size and the model of string bits

We consider the discretization effects of a string-bit model simulating the near-BMN operators in the super--Yang--Mills model. The fermionic sector of this model is altered by the so called species doubling. We analyze the possibilities to cure this disease and propose an alternative formulation of the fermionic sector free from the above drawbacks. Also we propose a formulation of string bits with exact supersymmetry, which produces however an even number of continuous strings in the limit $J\to\infty$.Comment: 10 pages, Contribution to BW2003 Workshop, 29 August - 02 September, 2003 Vrnjacka Banja, Serbi

Noncommutative Tachyonic Solitons. Interaction with Gauge Field

We show that in the presence of U(1) noncommutative gauge interaction the noncommutative tachyonic system exhibits solitonic solutions for finite value of the noncommutativity parameter.Comment: 9 pages, no figures, latex changes,some comments adde

On dilatation operator for a renormalizable theory

Given a renormalizable theory we construct the dilatation operator, in the sense of generator of RG flow of composite operators. The generator is found as a differential operator acting on the space of normal symbols of composite operators in the theory. In the spirit of AdS/CFT correspondence, this operator is interpreted as the Hamiltonian of the dual theory. In the case of a field theory with non-abelian gauge symmetry the resulting system is a matrix model. The one-loop case is analyzed in details and it is shown that we reproduce known results from N=4 supersymmetric Yang-Mills theory.Comment: 26 pages, no figure