/ 02 01 27 9 v 1 3 0 Ja n 20 02 Random Phase Approximation and extensions applied to a bosonic field theory

/ 02 01 28 9 v 1 3 0 Ja n 20 02 The η ′ → ηππ decay in U ( 3 ) chiral perturbation theory 1

ar X iv : h ep - t h / 02 01 13 3 v 1 1 7 Ja n 20 02 Semiclassical zero temperature black holes in spherically reduced theories

We numerically integrate the semiclassical equations of motion for spherically symmetric Einstein-Maxwell theory with a dilaton coupled scalar field and look for zero temperature configurations. The solution we find is studied in detail close to the horizon and comparison is made with the corresponding one in the minimally coupled case. Email: [email protected] Email: [email protected] 1

ar X iv : h ep - p h / 02 01 17 0 v 1 1 8 Ja n 20 02 Chiral Lagrangian with confinement from the QCD Lagrangian

An effective Lagrangian for the light quark in the field of a static source is derived systematically using the exact field correlator expansion. The lowest Gaussian term is bosonized using nonlocal colorless bosonic fields and a general structure of effective chiral Lagrangian is obtained containing all set of fields. The new and crucial result is that the condensation of scalar isoscalar fiel...

ar X iv : h ep - t h / 02 01 19 3 v 1 2 4 Ja n 20 02 Large N Limit of SO ( N ) Scalar Gauge Theory

In this paper we study the large Nc limit of SO(Nc) gauge theory coupled to a real scalar field following ideas of Rajeev[1]. We will see that the phase space of this resulting classical theory is Sp1(H)/U(H+) which is the analog of the Siegel disc in infinite dimensions. The linearized equations of motion give us a version of the well-known ’t Hooft equation of two dimensional QCD.

ar X iv : h ep - t h / 02 01 03 3 v 2 1 4 Ja n 20 02 String with noncommutative world - sheet and stringy instantons

The model of the bosonic string with the noncommutative world-sheet geometry is proposed in the framework of Fedosov's deformation quantization. The re-interpretation of the model in terms of bosonic string coupled to infinite multiplet of background fields is given and the link to the W-symmetry is discussed. For the case of d=4 Euclidean target space, the stringy counterparts of the Yang-Mill...