Rolling the tachyon in super BSFT

We investigate the rolling of the tachyon on the unstable D9 brane in Type IIA string theory by studying the BSFT action. The action is known for linear profiles of the tachyon, which is the expected asymptotic behavior of the tachyon as it approaches the closed string vacuum, as recently described by Sen. We find that the action does indeed seem consistent with the general Sen description, in that it implies a constant energy density with diminishing pressure. However, the details are somewhat different from an effective field theory of Born-Infeld type. For instance, the BSFT action implies there are poles for certain rolling velocities, while a Born-Infeld action would have a cut. We also find that solutions with pressure diminishing from either the positive or negative side are possible.Comment: 8 pages LaTeX; v2, references adde

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

Quark-Monopole Potentials in Large N Super Yang-Mills

We compute the quark-monopole potential for ${\cal N}=4$ super Yang-Mills in the large $N$ limit. We find an attractive potential that falls off as 1/L and is manifestly invariant under $g\to 1/g$. The strength of the potential is less than the quark-antiquark and monopole-antimonopole potentials.Comment: 10 pages (harvmac), 2 figures; v.2 typos corrected, one paragraph rewritte

Baryon Configurations in the UV and IR Regions of Type 0 String Theory

The Type 0 string theory is considered as a dual model of a non-supersymmetric gauge theory. A background geometry with N electric D3-branes is calculated in UV/IR regions. In this paper, we study a D5-brane around N D3-branes from the D5-brane world volume action as in the Type IIB case, and we obtain some baryon configurations at UV/IR regions.Comment: 10 pages, 2 figures, harvmac+epsf, some errata correcte

Review of AdS/CFT Integrability, Chapter I.1: Spin Chains in N=4 Super Yang-Mills

In this chapter of "Review of AdS/CFT Integrability" we introduce N=4 Super Yang-Mills. We discuss the global superalagebra PSU(2,2|4) and its action on gauge invariant operators. We then discuss the computation of the correlators of certain gauge invariant operators, the so-called single trace operators in the large N limit. We show that interactions in the gauge theory lead to mixing of the operators. We compute this mixing at the one-loop level and show that the problem maps to a one-dimensional spin chain with nearest neighbor interactions. For operators in the SU(2) sector we show that the spin chain is the ferromagnetic Heisenberg spin chain whose eigenvalues are determined by the Bethe equations.Comment: 25 pages, see also overview article arXiv:1012.3982; v2: references to other chapters updated; v3: references added, typos fixe

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

Field theory models for tachyon and gauge field string dynamics

In hep-th/0008227, the unstable lump solution of \phi^3 theory was shown to have a spectrum governed by the solvable Schroedinger equation with the \ell=3 reflectionless potential and was used as a model for tachyon condensation in string theory. In this paper we study in detail an \ell\to \infty scalar field theory model whose lump solution mimics remarkably the string theory setup: the original field theory tachyon and the lump tachyon have the same mass, the spectrum of the lump consists of equally spaced infinite levels, there is no continuous spectrum, and nothing survives after tachyon condensation. We also find exact solutions for lumps with codimension \ge 2, and show that that their tensions satisfy (1/(2\pi)) (T_p/ T_{p+1})=e/(\sqrt{2\pi}) \approx 1.08. We incorporate gauge fixed couplings to a U(1) gauge field which preserve solvability and result in massless gauge fields on the lump.Comment: latex, 21 pages, 3 figures. Added references to reflectionless potentials, minor typos corrected, uniform use of (-, +, +, ..., +) signatur