Related papers: Grand-Unification Scale Generation through the Ano…
We consider realizations of GUT models in F-theory. Adopting a bottom up approach, the assumption that the dynamics of the GUT model can in principle decouple from Planck scale physics leads to a surprisingly predictive framework. An…
We make a detailed analysis of gauge coupling unification in supersymmetry. When the Standard Model gauge group is embedded in a Grand Unified Theory, new particles often appear below the GUT scale in order to predict the right…
The observed low-energy values of the $SU(3)\times SU(2)\times U(1)$ gauge couplings, extrapolated via the minimal Standard Model Renormalization Group evolution, hint at the exciting possibility of a Grand Unified Theory (GUT) at $M_U \sim…
The gauge coupling unification is one of main motivations in the split-SUSY scenario, and the existence of the grand unified theories (GUTs) is assumed. We examine how to realize split-SUSY mass spectrum in the context of GUTs and find that…
Asymptotic Grand Unification theories (aGUTs) in five dimensions provide a valid alternative to standard quantitative unification. We define the pathway towards viable models starting from a general unified bulk gauge symmetry. Imposing the…
In this talk, we discuss an attempt to construct a realistic model of the grand gauge-Higgs unification. We investigate a 5D SU(6) grand gauge-Higgs unification model compactified on an orbifold S^1/Z_2. Ordinary quarks and leptons,…
We analyze the symmetry-breaking patterns of grand unified theories from the point of view of a recently-proposed criterion of renormalization-group naturalness. We perform the analysis on simple non-SUSY SU(5) and SO(10) and SUSY SU(5)…
We consider a 5-dimensional SU(5) model wherein the symmetry is broken to the 4-dimensional Standard Model by compactification of the 5th dimension on an S^1/(Z_2 \times Z^\prime_2) orbifold. We identify the members of all SU(5)…
We propose a grand unified theory (GUT) pseudo-Nambu-Goldstone boson (pNGB) dark matter (DM) model based on $SU(7)$ gauge symmetry. In the GUT model, the Standard Model (SM) gauge symmetry $G_{\rm SM} := SU(3)_C\times SU(2)_L\times U(1)_Y$…
In the context of supersymmetric $SO(10)$ grand unified models, it is shown that the gauge symmetry breaking as well as a natural doublet--triplet splitting can be achieved with a minimal Higgs system consisting of a single adjoint and a…
By making a renormalization group analysis we explore the possibility of having a 331 model as the only intermediate gauge group between the standard model and the scale of unification of the three coupling constants. We shall assume that…
In a class of gauged $U(1)$ extended Standard Models (SMs), the breaking of the $U(1)$ symmetry is not only a source for Majorana masses of right-handed (RH) neutrinos crucial for the seesaw mechanism, but also a source of stochastic…
The natural grand unified theories solve various problems of the supersymmetric grand unified theory and give realistic quark and lepton mass matrices under the natural assumption that all terms allowed by the symmetry are introduced with…
We describe a class of supersymmetric unified models with the following properties: i) the full breaking of the gauge group is achieved by Higgs fields in the fundamental representation; ii) the correct unification of the strong and…
We extend the Standard Model gauge group by a a gauged $U(1)_R$ R-Symmetry or a gauged $U(1)'$. The requirement of cancellation of anomalies is very constraining but can be achieved by adding three or four hidden-sector fields which are…
We investigate supersymmetric SU(5) grand-unified theories (GUTs) realized in 5 space-time dimensions and broken down to the MSSM by SU(5)-violating boundary conditions on a S^1/(Z_2 x Z_2') orbifold with two 3-branes. The doublet-triplet…
We explore the gauge coupling relations and the unification scale in F-theory SU(5) GUT broken down to the Standard Model by an internal U(1)Y gauge flux. We consider variants with exotic matter representations which may appear in these…
Maximally supersymmetric SO(10) and SU(6) unified theories are constructed on the orbifold T^2/(Z_2 x Z'_2), with one length scale R_5 taken much larger than the other, R_6. The effective theory below 1/R_6 is found to be the highly…
To solve the doublet-triplet splitting problem in SU(5) grand unified theories, we propose a four dimensional orbifold grand unified theory by acting Z2 on the SU(5) gauge group. Without an adjoint Higgs, the orbifold procedure breaks the…
The strategy for assigning $Z_{4R}$ parity in the string compactification is presented. For the visible sector, an anti-SU(5) (flipped-SU(5)) grand unification (GUT) model with three families is used to reduce the number of representations…