Propagators for massive symmetric tensor and p-forms in AdS(d+1)

We construct propagators in Euclidean AdS(d+1) space-time for massive p-forms and massive symmetric tensors.Comment: 22 page

Rolling Tachyons and Decaying Branes

We present new rolling tachyon solutions describing the classical decay of D-branes. Our methods are simpler than those appearing in recent works, yet our results are exact in classical string theory. The role of pressure in the decay is studied using tachyon profiles with spatial variation. In this case the final state involves an array of codimension one D-branes rather than static, pressureless tachyon matter.Comment: 24 page

Marginal Deformations from Branes

We study brane configurations for four dimensional N=1 supersymmetric gauge theories with quartic superpotentials which flow in the infrared to manifolds of interacting superconformal fixed points. We enumerate finite N=2 theories, from which a large class of marginal N=1 theories descend. We give the brane descriptions of these theories in Type IIA and Type IIB string theory. The Type IIB descriptions are in terms of D3 branes in orientifold and generalized conifold backgrounds. We calculate the Weyl and Euler anomalies in these theories, and find that they are equal in elliptic models and unequal in a large class of finite N=2 and marginal N=1 non-elliptic theories.Comment: 42 pages, minor changes, references adde

Some Aspects of the AdS/CFT Correspondence

This is a very brief review of some aspects of the AdS/CFT correspondence with an emphasis on the role of the topology of the boundary and the meaning of the sum over bulk geometries. To appear in the proceedings of the 73rd Meeting between Physicists and Mathematicians ``(A)dS/CFT correspondence,'' Strasbourg, September 11-13, 2003.Comment: LaTeX, 32 pages, 1 figure. To appear in the proceedings of the 73rd Meeting between Physicists and Mathematicians ``(A)dS/CFT correspondence,'' Strasbourg, September 11-13, 2003. v3: minor changes and references adde

Instabilities of the Small Black Hole: a view from N=4 SYM

We compute a one-loop effective action for the constant modes of the scalars and the Polyakov loop matrix of N=4 SYM on S^3 at finite temperature and weak 't Hooft coupling. Above a critical temperature, the effective potential develops new unstable directions accompanied by new saddle points which only preserve an SO(5) subgroup of the SO(6) global R-symmetry. We identify this phenomenon as the weak coupling version of the well known Gregory-Laflamme localization instability in the gravity dual of the strongly coupled field theory: The small AdS_5 black hole when viewed as a ten dimensional, asymptotically AdS_5 X S^5 solution smeared on the S^5 is unstable to localization on S^5. Our effective potential, in a specific Lorentzian continuation, can provide a qualitative holographic description of the decay of the "topological black hole'' into the AdS bubble of nothing.Comment: 39 pages, 6 figures, uses JHEP3.cls, references adde

On Marginal Deformations in Superstring Field Theory

We use level truncated superstring field theory to obtain the effective potential for the Wilson line marginal deformation parameter which corresponds to the constant vacuum expectation value of the U(1) gauge field on the D-brane in a particular direction. We present results for both the BPS and the non-BPS D-brane. In the case of non-BPS D-brane the effective potential has branches corresponding to the extrema of the tachyon potential. In the branch with vanishing tachyon vev (M-branch), the effective potential becomes flatter as the level of the approximation is increased. The branch which corresponds to the stable vacuum after the tachyon has condensed (V-branch) exists only for a finite range of values of marginal deformation parameter. We use our results to find the mass of the gauge field in the stable tachyonic vacuum. We find this mass to be of a non-zero value which seems to stabilize as the level approximation is improved.Comment: 20 pages, 8 figure

A Non-Supersymmetric Large-N 3D CFT And Its Gravity Dual

We propose a three dimensional non-supersymmetric theory that is conformal in the large N limit. In a certain well defined bosonic sub-sector of gauge invariant operators, this theory is planar equivalent to the theory recently proposed by Aharony, Bergman, Jafferis and Maldacena as the theory on multiple M2 branes at an orbifold singularity. We discuss the realization of the theory on a brane configuration of type 0B string theory. Moreover, we propose an 11D gravity dual, obtained by a projection of M-theory on AdS4 x S7 / Z_k.Comment: 11 pages, LaTex. 2 eps figures. v2: minor changes, references added. v3: version to appear in JHE

N=4 SYM on S^3 with Near Critical Chemical Potentials

We study the N = 4 theory at weak coupling, on a three sphere in the grand canonical ensemble with R symmetry chemical potentials. We focus attention on near critical values for the chemical potentials, above which the classical theory has no ground state. By computing a one loop effective potential for the light degrees of freedom in this regime, we show the existence of flat directions of complex dimension N, 2N and 3N for one, two and three critical chemical potentials respectively; these correspond to one half, one quarter and one-eighth BPS states becoming light respectively at the critical values. At small finite temperature we show that the chemical potentials can be continued beyond their classical limiting values to yield a deconfined metastable phase with lifetime diverging in the large N limit. Our low temperaure analysis complements the high temperature metastability found by Yamada and Yaffe. The resulting phase diagram at weak coupling bears a striking resemblance to the strong coupling phase diagram for charged AdS black holes. Our analysis also reveals subtle qualitative differences between the two regimes.Comment: 34 pages, 4 figure

The propagator for a general form field in AdSd+1AdS_{d+1}

Using the known propagator equations for 0,1 and 2 forms in AdS_{d+1}, we find the p-form field propagator equations in dimensions where the forms are Poincare dual. Since the general equation obeyed by the propagators is linear in dimension, this gives us the equation obeyed by the propagators for any d. Furthermore, based on the Poincare duality formulas for 0,1,2 and 3 forms we conjecture the general form of the Poincare duality formulas, and check them against the previously found propagator equations. The whole structure is self-consistent. Once we have the equations, we can easily obtain all the p-form field propagators in AdS_{d+1}. The generalization to massive p-forms can also be easily done.Comment: Extra chapter added on massive p-forms. 10 pages, REVTE