Related papers: Quantum Field Theories With Compact Noncommutative…
Motivated by the electroweak hierarchy problem, we consider theories with two extra dimensions in which the four-dimensional scalar fields are components of gauge boson in full space. We explore the Nielsen-Olesen instability for SU(N) on a…
In the framework of noncompact Kaluza-Klein theory, we investigate a $(4+1)$-dimensional universe consisting of a $(4+1)$ dimensional Robertson-Walker type metric coupled to a $(4+1)$ dimensional energy-momentum tensor. The matter part…
We review higher-dimensional unified theories from the general relativity, rather than the particle physics side. Three distinct approaches to the subject are identified and contrasted: compactified, projective and noncompactified. We…
We consider the noncommutative space $\mathbb{R}^3_\lambda$, a deformation of the algebra of functions on $\mathbb{R}^3$ which yields a "foliation" of $\mathbb{R}^3$ into fuzzy spheres. We first construct a natural matrix base adapted to…
We construct matter field theories in ``theory space'' that are fractal, and invariant under geometrical renormalization group (RG) transformations. We treat in detail complex scalars, and discuss issues related to fermions, chirality, and…
In many interesting models, including superstring theories, a negative vacuum energy is predicted. Although this effect is usually regarded as undesirable from a cosmological point of view, we show that this can be the basis for a new…
We construct N=1 supersymmetric field theory in 4+2 dimensions compatible with the theoretical framework of 2T physics and its gauge symmetries. The fields are arranged into 4+2 dimensional chiral and vector supermultiplets, and their…
Nonlinear covariant parity-violating deformations of free spin-two gauge theory are studied in n>2 spacetime dimensions, using a linearized frame and spin-connection formalism, for a set of massless spin-two fields. It is shown that the…
Non-commutative Euclidean scalar field theory is shown to have an eigenvalue sector which is dominated by a well-defined eigenvalue density, and can be described by a matrix model. This is established using regularizations of R^{2n}_\theta…
A field-theoretical model for non-singular global cosmic strings is presented. The model is a non-linear sigma model with a potential term for a self-gravitating complex scalar field. Non-singular stationary solutions with angular momentum…
Though Quantum SuperString Theory has shown promise, there are some puzzling features like the extra dimensions, which are curled up in the Kaluza-Klein sense. On the other hand a recent formulation of what may be called Quantized Fractal…
It is emphasized that compactified little string theories have compact moduli spaces of vacua, which globally probe compact string geometry. Compactifying various little string theories on T^3 leads to 3d theories with exact, quantum…
We study cosmological solutions of type II string theory with a metric of the Kaluza--Klein type and nontrivial Ramond--Ramond forms. It is shown that models with only one form excited can be integrated in general. Moreover, some…
We incorporate the concept of dimensional reduction at high energies within the perturbative formulation of quantum field theory. In this new framework, space and momentum integrations are modified by a weighting function incorporating an…
We give a lattice theory treatment of certain one and two dimensional quantum field theories. In one dimension we construct a combinatorial version of a non-trivial field theory on the circle which is of some independent interest in itself…
Quantum fields on a stationary space-time in a rotating Killing reference frame are considered. Finding solutions of wave equations in this frame is reduced to a fiducial problem on a static background. The rotation results in a gauge…
We investigate D=4, N=1 F theory models realized by type IIB string compactification on toric threefolds. Massless spectra, gauge symmetries, phase transitions associated with divisor contractions and flops, and non-perturbative…
We discuss Kaluza-Klein theory for type $II\ b $ supergravity on the warped deformed conifold using a large radial distance limit of Klebanov-Strassler solution where the radial coordinate separates from angle coordinates for a background…
We consider the novel Kaluza-Klein (KK) scenario where gravity propagates in the $4+n$ dimensional bulk of spacetime, while gauge and matter fields are confined to the 3+1 dimensional world-volume of a brane configuration. For simplicity we…
Quantum field theory (QFT) on non-stationary spacetimes is well understood from the side of the algebra of observables. The state space, however, is largely unexplored, due to the non-existence of distinguished states (vacuum, scattering…