We provide an explicit solution representing anisotropic power law inflation within the framework of rolling tachyon model. This is generated by allowing a non-minimal coupling between and world-volume gauge field on non-BPS D3 brane. also show that this perturbatively stable.

Using AdS/CFT prescription, we compute two point Yang-Mills correlator on a constant time slice for the Kasner background. Pushing surface close to initial singularity, find, in some cases, does not develop pole. We further numerically calculate similar where bulk is AdS soliton. find that qualitative behaviour of remains unchanged.

We assume that the early universe is homogeneous, anisotropic, and dominated by mutually Bogomol'nyi-Prasad-Sommerfeld ${22}^{\ensuremath{'}}{55}^{\ensuremath{'}}$ intersecting branes of M theory. The spatial directions are all taken to be toroidal. Using analytical numerical methods, we study evolution such an universe. find that, asymptotically, three expand infinity remaining reach stabilized values. Any values can obtained a fine-tuning initial brane densities. give physical description...

Our model consists of intersecting ${22}^{\ensuremath{'}}{55}^{\ensuremath{'}}$ branes in M theory distributed uniformly the common transverse space. Equations state follow from $U$ duality symmetries. In this model, three spatial directions expand, and seven stabilize to constant sizes. From a string perspective, dilaton is hence stabilized. The sizes depend on certain imbalance among initial values. One naturally obtains ${M}_{11}\ensuremath{\simeq}{M}_{s}\ensuremath{\simeq}{M}_{4}$...

A bstract We define Radon transform and its inverse on the two-dimensional anti-de Sitter space over local fields using a novel construction through quadratic equation field. show that holographic bulk reconstruction of quantum in this can be formulated as transform, generalizing case reals, studied earlier.

We consider general black hole solutions in five-dimensional spacetime the presence of a negative cosmological constant.We obtain evolution via gravity/gauge theory duality (holography) by defining appropriate boundary conditions on four-dimensional hypersurface.The standard counterterms are shown to renormalize bare parameters system (the Newton's constant and constant).We discuss thermodynamics present various examples.The braneworld scenarios be special cases our holographic construction.

Bulk reconstruction formulas similar to HKLL are obtained for de Sitter and anti-de spaces as the inverse Gel'fand Graev Radon transform. While these generalize our previous result on Euclidean space, their validity in here is restricted only odd dimensions both instances. The exact Wightman function space then derived analytically. GGR transform fixes coefficient of function. For it shown that a formula exists case time-like boundary well. restriction domain integration derived. As special...

The relation between kinematic space metric and entanglement entropy provides us with a differential equation for entropy. For BCFT on upper half plane we solve this to obtain an expression consistent known results in the literature. We also discuss how can be used recast RG flow, under relevant deformations of CFT, as flow metrics.

The bulk reconstruction formula for a Euclidean anti-de Sitter space is directly related to the inverse of Gel'fand-Graev-Radon transform. Correlation functions conformal scalar field theory in boundary are thereby correlation self-interacting at different loop orders.

In this thesis we study early universe in the frame work of M theory. particular We assume that is homogeneous, anisotropic, and dominated by mutually BPS 22'55' intersecting branes find that, asymptotically, three spatial directions expand to infinity remaining reach stabilised values. give a physical description stabilisation mechanism.

We describe rotating multicharge black holes as stacks of intersecting branes and antibranes together with massless gases on them. Assuming the energies to be equal, we find that their angular momentum parameters, corresponding hole rotations, are also equal. The entropy S this model is given by = X S_{sg} where supergravity entropy. One can obtain 1 under an assumption which violates conservation energy. show obtained if one assumes there only single gas, some sort superposition mentioned...

Using AdS/CFT prescription, we compute two point Yang-Mills correlator on a constant time slice for the Kasner background. Pushing surface close to initial singularity, find, in some cases, does not develop pole. This is consistent with observations made recent work. We further numerically calculate similar where bulk AdS soliton. find that qualitative behaviour of remains unchanged.

U-duality symmetry of M-theory and S T-duality string theory can be used to study various black branes solutions. We explore some aspect this idea here. This get relations among components the metric brane. These in turn give energy-momentum tensor. show that, using these relations, without knowing explicit form fields, we brane features were studied previously context M-theory. Here extensively them (type II supergravity). also that formulation works for exotic branes. an example a...

It is well known that Kasner geometry with spacelike singularity can be extended to bulk AdS-like geometry, furthermore, one study field theory on this space via its gravity dual. In paper, we show there exists a Kasner-like timelike for which construct dual description. We then various extremal surfaces including geodesics in the Finally, compute correlators of highly massive operators boundary geodesic approximation.

Our model consists of intersecting 22'55' branes in M theory distributed uniformly the common transverse space. Equations state follow from U duality symmetries. In this model, three spatial directions expand, and seven stabilise to constant sizes. From string perspective, dilaton is hence stabilised. The sizes depend on certain imbalance among initial values. One naturally obtains M_{11} \simeq M_s M_4 g_s 1 within a few orders magnitude. Smaller numbers, for example 10^{- 16} M_4, are also...