Related papers: Gauge Coupling Unification with Extra Dimensions a…
We present a concise survey of the running of gauge couplings in realistic models of gauge-Higgs grand unification in a slice of AdS$_5$ space and investigate their potential unification. Besides unifying the gauge groups of the Standard…
The derived modular invariant one-loop string effective coupling constant has been used to discuss the weak scale measurement constraints on minimal superstring models, minimal SUSY left-right string models and minimal left-right SUSY…
We explore in a model independent way the possibility of achieving the non supersymmetric gauge coupling unification within left-right symmetric models, with the minimal particle content at the left-right mass scale which could be as low as…
The possibility of achieving a gauge coupling grand unification by increasing the QCD degrees of freedom at higher energies is investigated. When confronted with precision low-energy data, the generic weak-mixing angle relation…
We consider the gauge coupling running in a six-dimensional SO(10) orbifold GUT model. The bulk gauge symmetry is broken down to the standard model gauge group with an extra U(1)_X by orbifold boundary conditions and the extra U(1)_X is…
We discuss gauge coupling unification in models with additional 1 to 4 complete vector-like families, and derive simple rules for masses of vector-like fermions required for exact gauge coupling unification. These mass rules and the…
We consider the low-energy signatures of, and high-energy motivations for, scenarios of semi-perturbative gauge coupling unification. Such scenarios can leave striking imprints on the low-energy sparticle spectrum, including novel gaugino…
Gauge coupling unification and the stability of the Higgs vacuum are among two of the cherished features of low-energy supersymmetric models. Putting aside questions of naturalness, supersymmetry might only be realised in nature at very…
A realistic SU(3)_C x SU(3)_W unified theory is constructed with a TeV sized extra dimension compactified on the orbifold S_1/Z_2, leaving only the standard model gauge group SU(3)_C x SU(2)_L x U(1)_Y unbroken in the low energy 4D theory.…
We review briefly the main features of the Large Extra Dimensions scenario in the framework of weakly coupled Type I string theory. Kaluza-Klein (KK) excitations of the graviton are expected, whereas no KK modes for the gauge bosons arise…
We consider a theory with the gauge group $E_8$ assuming that the gauge symmetry breaking pattern is $E_8 \to E_7 \times U_1 \to E_6 \times U_1 \to SO_{10} \times U_1 \to SU_5 \times U_1 \to SU_3 \times SU_2 \times U_1$ and vacuum…
In this letter, we study the implications of precise gauge coupling unification on supersymmetric particle masses. We argue that precise unification favors the superpartner masses that are in the range of several TeV and well beyond. We…
In Grand Unified Theories (GUTs), the Standard Model (SM) gauge couplings need not be unified at the GUT scale due to the high-dimensional operators. Considering gravity mediated supersymmetry breaking, we study for the first time the…
We argue that supersymmetry breaking by gaugino condensation in the strongly coupled heterotic string can be described by an analogue of Scherk-Schwarz compactification on the eleventh dimension in M-theory. The M-theory scale is identified…
Effective dimension-5 operators which modify the gauge kinetic term in Grand Unified Theories may arise as a consequence of quantum gravity or string compactification. We exhaustively calculate the modification of the gauge unification…
We study the evolution of the gauge coupling constants in string unification schemes in which the light spectrum below the compactification scale is exactly that of the minimal supersymmetric standard model. In the absence of string…
Recently it has been proposed that, in the framework of quantum field theory, both the Standard Model gauge and Yukawa interactions arise from a single gauge interaction in higher dimensions with supersymmetry. This leads to the unification…
Gauge symmetry enhancing, at specific points of the compactification space, is a distinguished feature of string theory. In this work we discuss the breaking of such symmetries with tools provided by Double Field Theory (DFT). As a main…
Gauge Higgs Unification in Warped Extra Dimensions provides an attractive solution to the hierarchy problem. The extension of the Standard Model gauge symmetry to $SO(5)xU(1)_X$ allows the incorporation of the custodial symmetry $SU(2)_R$…
We study the implications of extra dimensions of size $R\sim 1/TeV$ on electroweak and flavor physics due to the presence of Kaluza-Klein excitations of the SM gauge-bosons. We consider several scenarios with the SM fermions either living…