相关论文: Probing mu-term Generation Mechanism in String Mod…

We study the modular symmetry in four-dimensional low-energy effective field theory, which is derived from type IIB magnetized D-brane models and type IIA intersecting D-brane models. We analyze modular symmetric behaviors of perturbative…

We review particle physics model building in type IIB string theory and F-theory. This is a region in the landscape where in principle many of the key ingredients required for a realistic model of particle physics can be combined…

We study a possibility of combining an origin of the $\mu$-term and the baryon and lepton number asymmetry. If we assume that the $\mu$-term is generated through a flat direction of a singlet scalar field, the coherent oscillation of this…

The stability of "visible" electroweak-type cosmic strings is investigated in an extension of the Standard Model (SM) by a minimal dark sector, consisting of a U(1) gauge field, broken spontaneously by a scalar. The "visible" and dark…

With the elements of the Doplicher, Fredenhagen and Roberts (DFR) noncommutative formalism, we have constructed the standard electroweak model. To accomplish this task we have begun with the WM-product basis group of symmetry. We have…

The focus of this thesis is on (1) the role of Ka\v c-Moody (KM) algebras in string theory and the development of techniques for systematically building string theory models based on higher level ($K\geq 2$) KM algebras and (2) fractional…

This thesis studies meta- and exactly stable supersymmetry breaking mechanisms in heterotic and type IIB string theories and constructs an F-theory Grand Unified Theory model for neutrino physics in which neutrino mass is determined by the…

We discuss how models of electroweak symmetry breaking based on strong dynamics lead to observable contributions to the Z-boson decay width to bbbar pairs even in the absence of any extended sector responsible for dynamical generation of…

We examine the soft supersymmetry breaking parameters that result from various ways of embedding the Standard Model (SM) on D-branes within the Type I string picture, allowing the gaugino masses and $\mu$ to have large CP- violating phases.…

Potentially realistic string models often contain additional abelian gauge factors besides the standard model group. The consequences of such extended gauge structure are manifold both for theory and phenomenology as I show focussing in the…

We go beyond parameterizations of soft terms in superstring models and investigate the dynamical assumptions that lead to the relative strength of the dilaton {\it vs} the moduli contributions in the soft breaking. Specifically, we discuss…

We present a mathematical framework for constructing the most general neutrino mass matrices that yield the observed spectrum of light active neutrino masses in conjunction with arbitrarily many heavy sterile neutrinos, without the need to…

Tree-level moduli stabilization via geometric and non-geometric fluxes in type IIB orientifolds on Calabi-Yau manifolds is investigated. The focus is on stable non-supersymmetric minima, where all moduli are fixed except for some massless…

We study the formation of D and F-cosmic strings in D-brane annihilation after brane inflation. We show that D-string formation by quantum de Sitter fluctuations is severely suppressed, due to suppression of RR field fluctuations in compact…

We briefly review the recent programme to construct, systematically and algorithmically, large classes of heterotic vacua, as well as the search for the MSSM therein. Specifically, we outline the monad construction of vector bundles over…

We study the generation of electromagnetic fields in a string-inspired scenario associated with a rolling massive scalar field $\phi$ on the anti-D3 branes of KKLT de Sitter vacua. The 4-dimensional DBI type effective action naturally gives…

We give a model-independent discussion of fermion masses in four-dimensional heterotic superstring theories. We discuss the tree level contributions and quantum corrections, including one-loop threshold effects and masses generated as a…

We describe the results of high-resolution numerical simulations of string-induced structure formation in open universes and those with a non-zero cosmological constant. For models with $\Gamma = \Omega h = 0.1 - 0.2$ and a cold dark matter…

Many extensions of the standard model, especially grand unified theories and superstring models, predict the existence of additional Z' bosons and associated exotic chiral supermultiplets. It has recently been argued that for classes of…

We employ powerful techniques based on Hilbert- and Groebner bases to analyze particle physics models derived from string theory. Individual models are shown to have a huge landscape of vacua that differ in their phenomenological…