Related papers: Reviving trinification models through an $\mathrm{…
Supersymmetric grand unified models based on SO(10) gauge symmetry have many desireable features, including the unification of Yukawa couplings. Using D-term contributions to scalar masses arising from the breakdown of SO(10), Yukawa…
We construct a 6D supergravity theory which emerges as intermediate step in the compactification of the heterotic string to the supersymmetric standard model in four dimensions. The theory has N=2 supersymmetry and a gravitational sector…
Grand unification groups (GUTs) are constructed from SO(32) heterotic string via $\Z_{12-I}$ orbifold compactification. So far, most phenomenological studies from string compactification relied on $\EE8$ heterotic string, and this invites…
We perform a detailed study of the grand unified theories $SO(10)$ and $E(6)$ with left-right intermediate gauge symmetries of the form $SU(N)_L\otimes SU(N)_R \otimes \mathcal{G}$. Proton decay lifetime constrains the unification scale to…
Boundary conditions on an extra-dimensional interval can be chosen to break bulk gauge symmetries and to reduce the rank of the gauge group. We consider this mechanism in models with gauge trinification. We determine the boundary conditions…
Motivated by D-brane scenarios, we consider a non-supersymmetric model based on the gauge symmetry U(3)_CxU(3)_LxU(3)_R$ which is equivalent to the SU(3)^3 ``trinification'' model supplemented by three U(1)s. Two U(1) combinations are…
Gauge-coupling unification is just as successful in the standard model with six Higgs doublets as it is in the minimal supersymmetric standard model. However, the gauge couplings unify at 10^14 GeV, which yields rapid proton decay in the…
As is well-known, Trinification, \ie, the extension of the Standard Model (SM) to $[SU(3)]^3=SU(3)_c\times SU(3)_L\times SU(3)_R$ as occurs in $E_6$ models, allows for a partial unification of the gauge forces even though quarks and leptons…
We construct a supersymmetric model based on the semi-simple gauge group $SU(3)_c \times SU(3)_L \times SU(3)_R$ with the relation $tan\beta \simeq m_t/m_b$ automatically arising from its structure. The model below a scale $\sim 10^{16}$…
SO(10) supersymmetric grand unified theories [SUSY GUTs] provide a beautiful framework for physics beyond the standard model. Experimental measurements of the three gauge couplings are consistent with unification at a scale $M_G \sim 3…
We propose a supersymmetric (SUSY) SU(5) Grand Unified Theory (GUT) including a single right-handed neutrino singlet and an adjoint matter representation below the GUT scale and extend this model to include an A4 family symmetry and a…
In the context of the standard SUSY GUT scenario, we present a detailed analysis of the softly broken finite supersymmetric grand unified theory. The model, albeit non-minimal, remains very rigid due to the requirement of finiteness. It is…
We consider the possibility of grand unification of the $\mathrm{ SU(3)_c \otimes SU(3)_L \otimes U(1)_X}$ model in an SU(6) gauge unification group. Two possibilities arise. Unlike other conventional grand unified theories, in SU(6) one…
We obtain a supersymmetric three family chiral SU(6) grand unification model with the global family symmetry SU(3)[family] from F-theory. This model has nice features such as all the fermion masses are reasonably generated and there results…
Inspired by a recently proposed GUT model based on the trinification ($\mathrm{SU}(3)^3$) gauge group with a global family ($\mathrm{SU}(3)_F$) symmetry, we consider an effective low-energy three Higgs doublet model that may shed light on…
We construct lists of supersymmetric models with extended gauge groups at intermediate steps, all of which are based on SO(10) unification. We consider three different kinds of setups: (i) The model has exactly one additional intermediate…
Supersymmetric (SUSY) grand unified theories (GUTs) appear to be best motivated for understanding strong, weak and electromagnetic interactions of nature. We briefly review emergence of new formulas for running fermion masses valid in…
It is proposed that supersymmetry (SUSY) maybe used to understand fermion mass hierarchies. A family symmetry Z_{3L} is introduced, which is the cyclic symmetry among the three generation SU(2) doublets. SUSY breaks at a high energy scale ~…
Unification of Gauge and Yukawa sectors of GUTs is obtained by searching for renormalization group invariant relations among the couplings of the both sectors which hold beyond the unification scale. This procedure singled out two…
We present a supersymmetric grand unification scheme based on the gauge group SU(3)_c X SU(3)_L X SU(3)_R in which the proton and the lightest supersymmetric particle are stable, neutrinos are necessarily massive, and the observed baryon…