Related papers: Electroweak Strings and Fermions
We review some recent developments in string theory, emphasizing the importance of vacuum instabilities, their relation to the density of states, and the role of space-time fermions in non-critical string theory. We also discuss the…
The recent extension of the standard model to include massive neutrinos in the framework of noncommutative geometry and the spectral action principle involves new scalar fields and their interactions with the usual complex scalar doublet.…
We investigate the region of restored electroweak symmetry around a superconducting cosmic string coupled to the Weinberg-Salam model with an extra Higgs doublet. We show that the presence of the extra Higgs fields, and in particular their…
We explore the phenomenological viability of a light Z' in heterotic-string models, whose existence has been motivated by proton stability arguments. A class of quasi-realistic string models that produce such a viable Z' are the Left-Right…
Recently it was demonstrated that free fermionic heterotic-strings can produce models with solely the Minimal Supersymmetric Standard Model states in the low energy spectrum. This unprecedented result provides further strong evidence for…
We consider the 1-loop effective potential in type I string theory compactified on a torus, with supersymmetry broken by the Scherk-Schwarz mechanism. At fixed supersymmetry breaking scale M, and up to exponentially suppressed terms, we…
We investigate recent claims concerning a new class of cosmic string solutions in the Weinberg-Salam model. They have the general form of previously discussed semi-local and electroweak strings, but are modified by the presence of a…
We consider singlet extensions of the standard model, both in the fermion and the scalar sector, to account for the generation of neutrino mass at the TeV scale and the existence of dark matter respectively. For the neutrino sector we…
In the first part of this paper I review the construction of the realistic free fermionic models, as well as current attempts to study aspects of these models in the nonperturbative framework of M- and F-theories. I discuss the recent…
We analyse descriptions of electroweak symmetry breaking in terms of ultralocal antisymmetric tensor fields and gauge-singlet geometric variables, respectively; in particular, the Weinberg--Salam model and, ultimately, dynamical electroweak…
We consider coupled gravitational and electromagnetic perturbations of a family of five-dimensional Einstein-Maxwell solutions that describes both magnetized black strings and horizonless topological stars. We find that the odd…
In this paper we describe a new type of topological defect, called a homilia string, which is stabilized via interactions with the string network. Using analytical and numerical techniques, we investigate the stability and dynamics of…
Ab initio electronic structure calculations show that the recently identified quasi-two-dimensional electride Y$_2$C is a weak itinerant ferromagnet or at least close to a ferromagnetic instability. The ferromagnetism is induced by the…
In this paper, we study the stability problem of a star-shaped network of elastic strings with a local Kelvin-Voigt damping. Under the assumption that the damping coefficients have some singularities near the transmission point, we prove…
We study the distribution of graded degrees of freedom in classically stable oriented closed string vacua and use the Rankin-Selberg transform to link it to the finite one-loop vacuum energy. In particular, we find that the spectrum of…
In models in which some of the scalar field are charged and some uncharged, interactions with a finite temperature plasma will lead to corrections to the effective potential of the charged fields which may stabilize embedded defects made up…
In this paper we study fermion perturbations in four dimensional black holes of string theory, obtained either from a non-extreme configuration of three intersecting five-branes with a boost along the common string or from a non-extreme…
We investigate the dependence of the number and type of untwisted moduli on the boundary condition vectors of relistic free fermionic strings. The number of moduli is given by six minus the number of complex internal world--sheet fermions…
The existence of an extra Z' inspired from heterotic-string theory at accessible energy scales attracted considerable interest in the particle physics literature. Surprisingly, however, the construction of heterotic--string derived models…
We give a topological classification of stable and unconfined massive particles and strings (and some instantons) in worldvolume theories of M5-branes and their dimensional reductions, generalizing Witten's classification of strings in SYM.…