相关论文: A grand unified model with $M_G\sim M_{string}$ an…

We present a model based on the gauge group SU(2)$_L\times$SU(2)$_R\times$SU(4)$_C$ with gauge couplings that are found to be unified at a scale $M_G$ near the string unification scale. The model breaks to the minimal supersymmetric…

We present a grand unified model based on the supersymmetric $SU(3)_L\otimes SU(3)_{CL}\otimes SU(3)_{CR}\otimes SU(3)_R$ gauge group, which unifies in one single step the three gauge couplings of the standard model at an scale $M\sim…

Considerations of massive neutrinos, baryogenesis as well as fermion mass textures in the grand unified theory framework provide strong motivations for supersymmetric(SUSY) SO(10) as the theory beyond the standard model. If one wants to…

We studied a left-right symmetric model that can accommodate the neutrino dark energy (\nd) proposal. Type III seesaw mechanism is implemented to give masses to the neutrinos. After explaining the model, we study the consistency of the…

We summarize recent studies of realistic nonsupersymmetric Grand Unified Theories (GUTs) extended with a global $U(1)_{\rm PQ}$ symmetry, so as to accommodate the axion solution to the strong CP problem. Aside from solving the CP problem…

Unlike minimal SU(5), SO(10) provides a straightforward path towards gauge coupling unification by modifying the renormalization group evolution of the gauge couplings above some intermediate scale which may also be related to the seesaw…

We construct and analyze an $SU(6)\times SU(2)$ GUT. The model is k=1 string embedable in the sense that we employ only chiral representations allowed at the k=1 level of the associated Ka\v{c}-Moody Algebra. Both cases $SU(6)\times…

Adjoint supermultiplets (1,3,0) and (8,1,0) modify the evolution of gauge couplings. If the unification of gauge couplings occurs at the string scale, their masses are fixed at around $10^{13}$ GeV. This scale coincides with expected…

A supersymmetric model with gauge symmetry G_1 X G_2, where G_i=SU(3)_i X SU(2)_i X U(1)_i, is constructed within the framework of gauge mediated supersymmetry breaking. At the energy scale (10-100) TeV where the gauge symmetry breaks down…

We consider a supersymmetric Grand Unified Theory (GUT) based on the gauge group SO(10) suggested by Aulakh et al., which features two--step intermediate symmetry breaking, $SO(10) \to SU(4)_C \times SU(2)_L \times SU(2)_R \to SU(3)_C…

The idea of quark-lepton universality at high energies has been introduced as a natural extension to the standard model. This is achieved by endowing leptons with new degrees of freedom -- leptonic colour, an analogue of the familiar quark…

A class of supersymmetric grand unified theories is introduced that has a single scale below the cutoff, that of the supersymmetry breaking masses $\tilde{m}$. For a wide range of the dimensionless parameters, agreement with the observed…

We construct a $SU(3)^3$ supersymmetric gauge theory with a common gauge coupling g. Spontaneous breaking of this gauge group at a scale $M_X=1.3\times10^{16} $GeV gives naturally rise exactly to the Minimal Supersymmetric Standard Model…

Gauge coupling unification is studied in the MSSM with non-universal soft supersymmetry breaking terms. If gaugino masses are sufficiently smaller than scalar soft masses and the scalar soft masses have also certain types of…

A model of dark energy and dark matter was proposed earlier by one of us (PQH) which involved an unbroken gauge group $SU(2)_Z$ whose coupling $\alpha_Z \equiv g_Z^2/4 \pi\sim O(1)$ at a scale $\Lambda_Z \sim 3 \times 10^{-3} eV$ starting…

The stability of dark matter is naturally explained if there is an additional U(1) symmetry which is spontaneously broken to a discrete symmetry at a high-energy scale. Such a framework is realized in the context of the SO(10) grand…

We develop a grand unified theory of matter and forces based on the gauge symmetry $SU(5)_L\times SU(5)_R$ with parity interchanging the two factor groups. Our main motivation for such a construction is to realize a minimal GUT embedding of…

A grand unified model based on SU(5) and supersymmetry is presented. Pairs of superfields belonging to 15 and 15* representations are newly introduced, while gauge coupling unification is satisfied. Improper mass relations in the minimal…

We propose a grand unified model in five dimensions that addresses the strong CP problem. In this framework, the boundary conditions that break the unified gauge group into the Standard Model gauge group simultaneously explain the mass…

We propose a grand unified SU(5)$\times$U(1)$_X$ model, where the standard SU(5) grand unified theory is supplemented by minimal seesaw and a right-handed neutrino dark matter with an introduction of a global $Z_2$-parity. In the presence…