Asymptotic Freedom and Confinement from Type 0 String Theory

We argue that there are generic solutions to the type 0 gravity equations of motion that are confining in the infrared and have log scaling in the ultraviolet. The background curvature generically diverges in the IR. Nevertheless, there exist solutions where higher order string corrections appear to be exponentially suppressed in the IR with respect to the leading type 0 gravity terms. For these solutions the tachyon flows to a fixed value. We show that the generic solutions lead to a long range linear quark potential, magnetic screening and a discrete glueball spectrum. We also estimate some WKB glueball mass ratios and compare them to ratios found using finite temperature models and lattice computations.Comment: 25 pages; harvmac (b); v2 ref. added, typos corrected;v3 minor change to sec. 3, more sol'ns considered in sec.4, revised WKB analysis in 5.

Glueball Mass Spectra and Other Issues for Supergravity Duals of QCD Models

We derive WKB expressions for glueball masses of various finite temperature supergravity models. The results are very close to recent numerical computations. We argue that the spectra has some universality that depends only on the dimension of the AdS space and the singularity structure of the horizon. This explains the stability of the $0^{++}$ glueball mass ratios between various models. We also consider the recently proposed nonsupersymmetric model arising from the type 0 string. In the supergravity limit of this model, the heavy quark potential has an effective coupling with 1/(log u) behavior in the UV. Unfortunately, the supergravity solution implies that the heavy quark potential is still coulombic in the infrared, with an effective coupling of order 1. We also argue that the type 0 supergravity background solution does not have normalizable glueball solutions.Comment: 19 pages, harvmac(b); v2: minor corrections, reference adde

Mode Interactions of the Tachyon Condensate in p-adic String Theory

We study the fluctuation modes for lump solutions of the tachyon effective potential in p-adic open string theory. We find a discrete spectrum with equally spaced mass squared levels. We also find that the interactions derived from this field theory are consistent with p-adic string amplitudes for excited string states.Comment: 17 pages, 1 figure, late

Three-point correlators from string amplitudes: Mixing and Regge spins

This paper has two parts. We first compute the leading contribution to the strong-coupling mixing between the Konishi operator and a double-trace operator composed of chiral primaries by using flat-space vertex operators for the string-duals of the operators. We then compute the three-point functions for protected or unprotected scalar operators with higher spin operators on the leading Regge trajectory. Here we see that the nontrivial spatial structures required by conformal invariance arise naturally from the form of the polarization tensors in the vertex operators. We find agreement with recent results extracted from Mellin amplitudes for four-point functions, as well as with earlier supergravity calculations. We also obtain some new results for other combinations of operators.Comment: v3: corrected numerical factor and other minor change