Related papers: Branes and the Gauge Hierarchy

We investigate the dynamics of gauge and scalar fields on unstable D-branes with rolling tachyons. Assuming an FRW metric on the brane, we find a solution of the tachyon equation of motion which is valid for arbitrary tachyon potentials and…

We deal with the problem of identifying a background structure and its perturbation in tetrad theories of gravity. Starting from a peculiar trivial principal bundle we define a metric which depends only on the gauge connection. We find the…

We elaborate further on a recently proposed scenario for generating a mass hierarchy through quantum fluctuations of a single D3 brane, which represents our world embedded in a bulk five-dimensional space time. In this scenario, the quantum…

We find novel bound states of NS5, D6 and D8-branes in massive Type IIA string theory. As the NS gauge transformations can change the Chern class of the RR field these configurations should be thought of as nonlocal objects called gerbes.…

We study the new ``gauge'' theories in 5+1 dimensions, and their non-commutative generalizations. We argue that the $\theta$-term and the non-commutative torus parameters appear on an equal footing in the non-critical string theories which…

A new class of warped Anti-de Sitter solutions is found, arising as the near-horizon region of various semi-localized brane intersections. The dual gauge theories of AdS in warped spacetimes have reduced supersymmetry, which is pertinent to…

We present a variant formulation of the Randall-Sundrum model which solves both the hierarchy and charge universality problems. We first critique the rationale for hierarchy solution and 4D effective interactions in the Randall-Sundrum…

We present a new type of self-tuning mechanism for ($3+p$)d brane world models in the framework of gravity-scalar theory. This new type of self-tuning mechanism exhibits a remarkable feature. In the limit $g_s \to 0$, $g_s$ being the string…

We revisit the construction of the $\mathcal{N}=1$ supersymmetric trinification models with gauge group $\mathrm{U}(3)_C\times \mathrm{U}(3)_L \times \mathrm{U}(3)_R$ in Type IIA string theory on $\mathbf{T^6/(\mathbb{Z}_2\times…

We review the construction and phenomenology of intersecting brane worlds. The breaking of chiral and supersymmetry together with a reduction of gauge symmetry by introducing D-branes at generic angles into type I or type II string…

When a quantum field theory has a symmetry, global or local like in gauge theories, in the tree or classical approximation formal manipulations lead to believe that the symmetry can also be implemented in the full quantum theory, provided…

Engineering quantum field theories in String Theory in terms of branes is a powerful approach for understanding their dynamics. We review recent progress in the realization of $2d$ $\mathcal{N}=(0,2)$ gauge theories in terms of branes. We…

This paper discusses the minimal quiver gauge theory embedding of the standard model that could arise from brane world type string theory constructions. It is based on the low energy effective field theory of D-branes in the perturbative…

The effective four-dimensional, linearised gravity for a brane world model with higher order curvature terms and a bulk scalar field is analysed. Large and small distance gravitational laws are derived. The model has a single brane embedded…

We examine the soft supersymmetry breaking parameters that result from various ways of embedding the Standard Model (SM) on D-branes within the Type I string picture, allowing the gaugino masses and $\mu$ to have large CP- violating phases.…

We study string realizations of split extended supersymmetry, recently proposed in hep-ph/0507192. Supersymmetry is broken by small ($\epsilon $) deformations of intersection angles of $D$-branes giving tree-level masses of order $m_0^2\sim…

We study gauge theories which are associated with classical vacua of perturbative Type II string theory that allows for a conformal field theory description. We show that even if we compactify seven spatial dimensions (allowing for one…

The problem of maintaining scale and conformal invariance in Maxwell and general N-form gauge theories away from their critical dimension d=2(N+1) is analyzed.We first exhibit the underlying group-theoretical clash between…

We study the restrictions imposed by cancellation of the tadpoles for two, three, and four-form gauge fields in string theory, M-theory and F-theory compactified to two, three and four dimensions, respectively. For a large class of…

We readdress the problems associated with bulk Higgs and the gauge fields in a 5-dimensional Randall-Sundrum model by extending the model to six dimensions with double warping along the two extra spatial dimensions. In this 6-dimensional…