We investigate de Sitter/conformal field theory (dS/CFT) correspondence in two dimensions. We define the conserved mass of de Sitter spacetime and formulate the correspondence along the lines of anti-de Sitter/conformal field theory duality. Asymptotic symmetry group, mass, and central charge of de Sitter spacetime are equal to those of anti-de Sitter spacetime. The entropy of two-dimensional d...

We consider the CFT of a free boson compactified on a circle, such that the compactification radius R2 is an irrational multiple of R2 selfdual. Apart from the standard Dirichlet and Neumann boundary states, Friedan suggested [1] that an additional 1-parameter family of boundary states exists. These states break U(1) symmetry of the theory, but still preserve conformal invariance. In this paper...

a Department of Mathematical Sciences, University of Durham, DH1 3LE, UK. Departamento de F́ısica Teórica, Universidad del Páıs Vasco, Apdo. 644, E-48080 Bilbao, Spain. b Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506–0055, USA. Physics Department, McGill University, Montréal, PQ, H3A 2T8, Canada. [email protected], [email protected], [email protected]...

By solving the right reflection equation proposed in reference[16] to describe the Z = 0 giant graviton branes, we obtain a boundary matrix with two free parameters for the AdS/CFT SU(1|1) spin chain.

We consider the low energy limit of a stack of N M-branes at finite temperature. In this limit, the M-branes are well described, via the AdS/CFT correspondence, in terms of classical solutions to the eleven dimensional supergravity equations of motion. We calculate Minkowski space two-point functions on these M-branes in the long-distance, low-frequency limit, i.e. the hydrodynamic limit, using...

We propose an effective model of strongly coupled gauge theory at finite temperature on R in the presence of an infrared cutoff. It is constructed by considering the theory on S with an infrared cutoff and then taking the size of the S to infinity while keeping the cutoff fixed. This model reproduces various qualitative features expected from its gravity dual. e-mail: [email protected] e-mai...

We study the localized tachyon condensation (LTC) of non-supersymmetric orbifold backgrounds in their mirror Landau-Ginzburg picture. Using he existence of four copies of (2,2) worldsheet supersymmetry, we show at the CFT level, that the minimal tachyon mass in twisted sectors shows somewhat analogous properties of cor g-function. Namely, m := |α′M2 min| satisfies m(M) ≥ m(D1 ⊕D2) = max{m(D1),m...

We derive a generalised concavity condition for potentials between static sources obtained from Wilson loops coupling both to gauge bosons and a set of scalar fields. It involves the second derivatives with respect to the distance in ordinary space as well as with respect to the relative orientation in internal space. In addition we discuss the use of this field theoretical condition as a nontr...

We present a new method to calculate the spectrum of (slow-roll) inflationary perturbations, inspired by the conjectured dS/CFT correspondence. We show how the standard result for the spectrum of inflationary perturbations can be obtained from deformed CFT correlators, whose behavior is determined by the Callan-Symanzik equation. We discuss the possible advantages of this approach and end with ...