We give analytical arguments and demonstrate numerically the existence of black hole
solutions of the 4D effective superstring action in the presence of Gauss-Bonnet quadratic …

Background In 1997, the National Hockey League (NHL) and NHL Players’ Association (NHLPA)
launched a concussion program to improve the understanding of this injury. We …

Free fermionic construction of four-dimensional string vacua, are related to the Z 2 ×Z 2
orbifolds at special points in the moduli space, and yielded the most realistic three family string …

We consider the O (α′) string effective action, with Gauss-Bonnet curvature-squared and
fourth-order dilaton-derivative terms, which is derived by a matching procedure with string …

We perform a systematic string computation of the masses of anomalous U(1) gauge bosons
in four-dimensional orientifold vacua, and we study their localization properties in the …

We continue the classification of the fermionic Z 2 ×Z 2 heterotic string vacua with symmetric
internal shifts. The space of models is spanned by working with a fixed set of boundary …

We extend the classification of free fermionic heterotic-string models to vacua in which the
SO(10) GUT symmetry is broken at the string level to the Pati–Salam subgroup. Using our …

Genetic Algorithms are introduced as a search method for finding string vacua with viable
phenomenological properties. It is shown, by testing them against a class of Free Fermionic …

We present explicit examples of semi-realistic heterotic models with spontaneously broken
supersymmetry, which dynamically lead to breaking scales much smaller than M Planck and …

We demonstrate the existence of heterotic string vacua that are free of massless exotic fields.
The need to break the non-Abelian GUT symmetries in k=1 heterotic string models by …