On the non-Abelian Stokes theorem in SU(2) gluodynamics

We discuss the non-Abelian Stokes theorem for SU(2) gauge fields which avoids both additional integration variables and surface ordering. The idea is to introduce the instant color orientation of the flux piercing the loop. The non-Abelian Stokes theorem is also considered on the lattice and various terms contributing to the trace of the Wilson loop are discussed.Comment: 3 pages, 2 figures, Lattice2003(topology

Correlators of currents corresponding to the massive pp-form fields in AdS/CFT correspondence

By solving the equations of motion of massive $p$-form potential in Anti-de-Sitter space and using the $AdS/CFT$ correspondence of Maldacena, the generating functional of two-point correlation functions of the currents is obtained. When the mass parameter vanishes the result agrees with the known massless case.Comment: 1+12 pages. Sequel to hep-th/9809132(the massless case with different method

Holographic dual of a time machine

We apply the $AdS/CFT$ holography to the simplest possible eternal time machine solution in $AdS_3$ based on two conical defects moving around their center of mass along a circular orbit. Closed timelike curves in this space-time extend all the way to the boundary of $AdS_3$, violating causality of the boundary field theory. By use of the geodesic approximation we address the "grandfather paradox" in the dual $1+1$ dimensional field theory and calculate the two-point retarded Green function. It has a non-trivial analytical structure both at negative and positive times, providing us with an intuition on how an interacting quantum field could behave once causality is broken. In contrast with the previous considerations our calculations reveal the possibility of a consistent and controllable evolution of a quantum system without any need to impose additional consistency constraints.Comment: 37 pages, 26 figure

A numerical study of the RG equation for the deformed O(3)O(3) nonlinear sigma model

The Renormalization Group equation describing the evolution of the metric of the nonlinear sigma model poses some nice mathematical problems involving functional analysis, differential geometry and numerical analysis. In this article we briefly report some results obtained from the numerical study of the solutions in the case of a two dimensional target space (deformation of the $O(3)$ sigma model). In particular, our analysis shows that the so-called sausages define an attracting manifold in the $U(1)$-symmetric case, at one-loop level. Moreover, data from two-loop evolution are used to test the association put forward in Nucl. Phys., B406 (1993) 521 between the so-called $SSM_{\nu}$ field theory and a certain $U(1)$-symmetric, factorized scattering theory (FST).Comment: LaTex (RevTex style), 16 pages, 6 uuencoded figures. Minor technical changes

On Black Hole Creation in Planckian Energy Scattering

In a series of papers Amati, Ciafaloni and Veneziano and 't Hooft conjectured that black holes occur in the collision of two light particles at planckian energies. In this talk based on \cite {AVV} we discuss a possible scenario for such a process by using the Chandrasekhar-Ferrari-Xanthopoulos duality between the Kerr black hole solution and colliding plane gravitational waves.Comment: Cont.Proc. of VI Quantum Gravity Seminar, 15 pages, LATE

Dynamical noncommutativity

We present a model of Moyal-type noncommutativity with time-depending noncommutativity parameter and the exact gauge invariant action for the U(1) noncommutative gauge theory. We briefly result the results of the analysis of plane-wave propagation in a regime of a small but rapidly changing noncommutativity.Comment: 10 pages, JHEP styl