Evidence for Nonvanishing Cosmological Constant in NonSusy Superstring Models

Abstract

We reanalyse the computation of the cosmological constant $\Lambda$ at two loops in recently proposed Superstring models without massless gravitini, both in the theta-function based formalism and by a detailed computation in the more explicit hyperelliptic description of the underlying genus two Riemann surface. $\Lambda$ is expressed as the integral over the surface moduli of an amplitude which is zero if susy is not completely broken, but we find it to be nonvanishing in the susy breaking models which can be given an explicitly workable fermionic formulation. Thus unfortunately the issue of getting realistic and perturbatively viable models from Superstring Theory remains open.

30 pages, Latex

Cited by in corpus (14)

• Two-Loop Superstrings I, Main Formulas
• Two-Loop Superstrings II, The Chiral Measure on Moduli Space
• Towards a Non-Supersymmetric String Phenomenology
• On exponential suppression of the cosmological constant in non-SUSY strings at two loops and beyond
• Two-Loop Superstrings on Orbifold Compactifications
• On the Construction of Asymmetric Orbifold Models
• Stability and vacuum energy in open string models with broken supersymmetry
• On interpolations from SUSY to non-SUSY strings and their properties
• The twisted open string partition function and Yukawa couplings
• Suppressing the Cosmological Constant in Non-Supersymmetric Type I Strings
• Vanishing Perturbative Vacuum Energy in Non-Supersymmetric Orientifolds
• Geometry of orientifold vacua and supersymmetry breaking
• Radiative stability of tiny cosmological constant from the Swampland and quantized compactification
• SUSY a consequence of smoothness?