Related papers: Non-Abelian Flat Directions in a Minimal Superstri…
We study a class of supersymmetric Froggatt-Nielsen (FN) models with multiple U(1) symmetries and Standard Model (SM) singlets inspired by heterotic string compactifications on Calabi-Yau threefolds. The string-theoretic origin imposes a…
We study field theoretical models for cosmic strings with flat directions in curved space-time. More precisely, we consider minimal models with semilocal, axionic and tachyonic strings, respectively. In flat space-time, the string solutions…
We find charged, abelian, spherically symmetric solutions (in flat space-time) corresponding to the effective action of $D=4$ heterotic string theory with scale-dependent dilaton $\p$ and modulus $\vp$ fields. We take into account…
It is shown that the quarks and leptons of the standard model, including a right-handed neutrino, can be obtained by gauging the holonomy groups of complex projective spaces of complex dimensions two and three. The spectrum emerges as…
We propose a non-universal U(1)'_F symmetry combined with the Minimal Supersymmetric Standard Model. All anomaly cancellation conditions are satisfied without exotic fields other than three right-handed neutrinos. Because our model allows…
We show that the classical equations of motion of the low-energy effective field theory describing the massless modes of the heterotic (or type I) string admit two classes of supersymmetric self--dual backgrounds. The first class, which was…
Extensions of the minimal supersymmetric standard model (MSSM) gauge group abound in the literature. Several of these include an additional $U(1)_X$ gauge group. Chiral fermions' charge assignments under $U(1)_X$ are constrained to cancel…
We construct non-supersymmetric type I string models which correspond to consistent flat-space solutions of all classical equations of motion. Moreover, the one-loop vacuum energy is naturally fixed by the size of compact extra dimensions…
We investigate the problem of the fermion mass hierarchy in supergravity models with flat directions of the scalar potential associated with some gauge singlet moduli fields. The low-energy Yukawa couplings are nontrivial homogeneous…
Building on recent advances in the understanding of gauge-Yukawa theories we explore possibilities to UV-complete the Standard Model in an asymptotically safe manner. Minimal extensions are based on a large flavor sector of additional…
We propose an extra-dimension framework on the orbifold $S^1/Z_2$ for understanding the origin of the fermion mass and mixing hierarchies. Introducing the flavor symmetry $G_F(=${\it non-Abelian}$\times${\it Abelian}) as well as the extra…
Common to many classes of three family SU(3)_C x SU(2)_L x U(1)_Y string models are an additional anomalous U(1)_A and numerous, often fractionally charged, exotic particles beyond the minimal supersymmetric standard model (MSSM). I present…
We continue the study of heterotic non-Abelian BPS-saturated flux tubes (strings). Previously, such solutions were obtained [1] in a particular U(2) gauge theory: N=2 supersymmetric QCD deformed by superpotential terms of a special type…
Starting from the previously constructed effective supergravity theory below the scale of U(1) breaking in orbifold compactifications of the weakly coupled heterotic string, we study the effective theory below the scale of supersymmetry…
We examine charge/colour breaking along directions in supersymmetric field space which are F and D-flat. We catalogue the dangerous directions and include some new ones which have not previously been considered. Analytic expressions for the…
Applying the results of Ref.[1], we carry out the non-abelian bosonization for a class of free fermion symmetry-protected topological states (SPTs). The resulting boson theories are non-linear sigma models with topological $\theta$ term,…
By the spin-fermion formula, the Hubbard model on the honeycomb lattice is represented by a U(2) gauge theory in the mean field method, non-Abelian vortex solutions are constructed based on this theory. The quantization condition shows that…
The string vertices of closed string field theory are subsets of the moduli spaces of punctured Riemann surfaces that satisfy a geometric version of the Batalin-Vilkovisky master equation. We present a homological proof of existence of…
We address intermediate scales within a class of string models. The intermediate scales occur due to the SM singlets S_i acquiring non-zero VEVs due to radiative breaking; the mass-square (m_i)^2 of S_i is driven negative at mu_{RAD} due to…
We calculate the weak scale MSSM spectrum starting from a heterotic string theory compactified on an anisotropic orbifold. Supersymmetry breaking is mediated by vector-like exotics that arise naturally in heterotic string theories. The…