In this paper we consider the influence of transplanckian physics on the CMBR anisotropies produced by inflation. We consider a simple toy model that allows for analytic calculations and argue on… (More)

In these lectures I review recent attempts to apply string theory to cosmology, including string cosmology and various models of brane cosmology. In addition, the review includes an introduction to… (More)

In this paper we investigate the relation between the bulk and boundary in AdS/CFT. We first discuss the relation between the Poincaré and the global vacua, and then study various probes of the bulk… (More)

We study the dynamics of D-particles (D0-branes) in type I’ string theory and of the corresponding states in the dual heterotic description. We account for the presence of the two 8-orientifolds (8… (More)

A model of 3+1 dimensional gravity with negative cosmological constant coupled to abelian gauge fields has been proposed as a gravity dual for Lifshitz like critical phenomena in 2+1 dimensions. The… (More)

A family of de Sitter vacua introduced in hep-th/0203198 as plausible initial conditions for inflation, are discussed from the point of view of de Sitter holography. The vacua are argued to be… (More)

We examine the T-duality relation between 1 + 1 NCOS and the DLCQ limit of type IIA string theory. We show that, as long as there is a compact dimension, one can meaningfully define an ‘NCOS’ limit… (More)

In this letter, we relate the free energy of the 0A matrix model to the sum of topological and anti-topological string amplitudes. For arbitrary integer multiples of the matrix model self-dual radius… (More)

We write down the weak-coupling limit of N=2 supersymmetric Yang-Mills theory with arbitrary gauge group G. We find the weak-coupling monodromies represented in terms of Sp(2r,Z) matrices depending… (More)

Recently it was shown that NCOS theories are part of a ten-dimensional theory known as Non-relativistic Wound string theory. We clarify the sense in which gravity is present in this theory. We show… (More)