Threshold Corrections and Symmetry Enhancement in String Compactifications

Abstract

We present the computation of threshold functions for Abelian orbifold compactifications. Specifically, starting from the massive, moduli-dependent string spectrum after compactification, we derive the threshold functions as target space duality invariant free energies (sum over massive string states). In particular we work out the dependence on the continuous Wilson line moduli fields. In addition we concentrate on the physically interesting effect that at certain critical points in the orbifold moduli spaces additional massless states appear in the string spectrum leading to logarithmic singularities in the threshold functions. We discuss this effect for the gauge coupling threshold corrections; here the appearance of additional massless states is directly related to the Higgs effect in string theory. In addition the singularities in the threshold functions are relevant for the loop corrections to the gravitational coupling constants.

68 pages (equations 8.16 and 8.17 corrected; added footnotes 4,5,11)

Cited by in corpus (44)

• Algebras, BPS States, and Strings
• Perturbative Couplings of Vector Multiplets in $N=2$ Heterotic String Vacua
• Black Holes and Solitons in String Theory
• Exact Standard model Structures from Intersecting D5-Branes
• Direct Integration of the Topological String
• New Principles for String/Membrane Unification
• M-Theory on a Calabi-Yau Manifold
• Universality properties of N=2 and N=1 Heterotic threshold corrections
• Gauge Unification in Highly Anisotropic String Compactifications
• Exact Standard Model Compactifications from Intersecting Branes
• One-Loop BPS amplitudes as BPS-state sums
• BPS Spectra and Non--Perturbative Couplings in N=2,4 Supersymmetric String Theories
• Exploring the landscape of heterotic strings on T^d
• How to Reach the Correct sin^2θ_W and α_S in String Theory
• $N=2$ heterotic string threshold correction, $K3$ surface and generalized Kac-Moody superalgebra
• Perturbative Couplings and Modular Forms in N=2 String Models with a Wilson Line
• Universal moduli-dependent thresholds in Z(2)xZ(2) orbifolds
• Counting BPS states on the Enriques Calabi-Yau
• Proton Hexality from an Anomalous Flavor U(1) and Neutrino Masses - Linking to the String Scale
• Kaluza-Klein Thresholds and Regularization (In)dependence
• String-dual $F_1$-Function in the Three Parameter Model
• Generalised universality of gauge thresholds in heterotic vacua with and without supersymmetry
• Compact Dimensions and their Radiative Mixing
• Higher-Order Gravitational Couplings and Modular Forms in $N=2,D=4$ Heterotic String Compactifications
• M-branes and N=2 Strings
• Threshold corrections, generalised prepotentials and Eichler integrals
• Gauge Unification in Extra Dimensions: Power Corrections vs. Higher-Dimension Operators
• String thresholds and Renormalisation Group Evolution
• Modular Invariance, Soft Breaking, $\mu$ and $\tan \beta$ in Superstring Models
• Regularisation Techniques for the Radiative Corrections of Wilson lines and Kaluza-Klein states
• Wilson lines corrections to gauge couplings from a field theory approach
• String Vacua with N=2 Supersymmetry in Four Dimensions
• Perturbative gravitational couplings and Siegel modular forms in $D=4,N=2$ string models
• Counting Curves with Modular Forms
• Borcherds Algebras and N=4 Topological Amplitudes
• Symplectic Embeddings and Special Kahler Geometry of CP(n-1,1)
• Gauge symmetry breaking in orbifold model building
• Gauge Symmetry Enhancement and N = 2 Supersymmetric Quantum Black Holes in Heterotic String Vacua
• Map of Heterotic and Type IIB Moduli in 8 Dimensions
• Threshold corrections in heterotic flux compactifications
• Perturbative and Non-Perturbative Results for $N=2$ Heterotic Strings
• Gauge and Gravitational Couplings from Modular Orbits in Orbifold Compactifications
• Shift-Symmetries at Higher Order
• Massive Theta Lifts