Related papers: $SO(10)$ thick branes and perturbative stability
A review of the current status of nucleon stability in SUSY unified models is given. The review includes analysis of nucleon stability in the minimal SU(5) supergravity model, and in extensions of the minimal model such as SO(10) models,…
Models with an extra dimension generally contain background scalar fields in a non-trivial configuration, whose stability must be ensured. With gravity present, the extra dimension is warped by the scalars, and the spin-0 degrees of freedom…
A class of exactly solvable models of domain walls are worked out in D=4 ${\cal N}=1$ supergravity. We develop a method to embed globally supersymmetric theories with exact BPS domain wall solutions into supergravity, by introducing a…
Within the framework of unified gauge models, interactions responsible for neutrino masses can also provide mechanisms for nucleon instability. We discuss their implications concretely in the light of recent results on neutrino oscillation…
Motivated by the recent use of certain consistent truncations of M-theory to study condensed matter physics using holographic techniques, we study the SU(3)-invariant sector of four-dimensional, N=8 gauged supergravity and compute the…
We study maximal supergravity in two dimensions, obtained from reduction of IIA supergravity on an $S^8$ sphere. The theory captures the low-lying fluctuations around the non-conformal D0-brane near-horizon geometry, dual to operators in…
We discuss the construction of Sp(2)Sp(1)-structures whose fundamental form is closed. In particular, we find 10 new examples of 8-dimensional nilmanifolds that admit an invariant closed 4-form with stabiliser Sp(2)Sp(1). Our constructions…
The minimal renormalizable supersymmetric SO(10) model, an SO(10) framework with only one 10 and one 126 Higgs multiplets in the Yukawa sector, is attractive because of its high predictive power for the neutrino oscillation data. However,…
We present a class of realistic unified models based on supersymmetric SO(10) wherein issues related to natural doublet-triplet (DT) splitting are fully resolved. Using a minimal set of low dimensional Higgs fields which includes a single…
With one exception, all known non-supersymmetric AdS$_4$ and AdS$_5$ vacua of gauged maximal supergravities that descend from string and M theory have been shown to have modes with mass below the BF bound. The remaining non-supersymmetric…
We investigate the large-N limit of the BMN matrix model with classical bosonic membranes which have spherical topologies and spin inside the 11-dimensional maximally supersymmetric plane-wave background. First we classify all possible…
The exceptional symmetry is realized perturbatively in F-theory which is the manifest U-duality theory. The SO(5,5) U-duality symmetry acts on both the 16 spacetime coordinates and the 10 worldvolume coordinates. Closure of the Virasoro…
Warped AdS$_3$ solutions in 10 dimensional supergravity that preserve ${\cal N}=(1,1)$ supersymmetry are considered. Sufficient geometric conditions for their existence, and to stop the AdS$_3$ factor experiencing an enhancement to AdS$_4$,…
We study the stability of 5D gravitational solutions containing an arbitrary number of scalar fields. A closed set of equations is derived which governs the background and perturbations of N scalar fields and the metric, for arbitrary bulk…
Two models which generate the supersymmetric Grand Unification Scale from the strong dynamics of an additional gauge group are presented. The particle content is chosen such that this group confines with chiral symmetry breaking. Fields…
In this Thesis we investigate properties of stability, rigidity and unitarity of the string landscape in ten and lower dimensions. The dissertation explores these aspects by intertwining a detailed analysis of string vacua, with and without…
We investigate the minimal Yukawa sector of grand unified theories based on $\mathrm{SO}(10)$ symmetry, consisting of a Higgs structure with representations $\mathbf{10}_{\mathbb{R}}\oplus \mathbf{120}_{\mathbb{R}}\oplus\mathbf{126}$. In…
We study a six-dimensional braneworld model with infinite warped extra dimensions in the case where the four-dimensional brane is described by a topological vortex of a U(1) symmetry-breaking Abelian Higgs model in presence of a negative…
We suggest a thick braneworld model in the squared curvature gravity theory. Despite the appearance of higher order derivatives, the localization of gravity and various bulk matter fields is shown to be possible. The existence of the…
We explore a variety of composite topological structures that arise from the spontaneous breaking of $SO(10)$ to $SU(3)_c \times U(1)_{em}$ via one of its maximal subgroups $SU(5) \times U(1)_\chi$, $SU(4)_c \times SU(2)_L \times SU(2)_R$,…