Modular invariant inflation

Abstract

Modular invariance is a striking symmetry in string theory, which may keep stringy corrections under control. In this paper, we investigate a phenomenological consequence of the modular invariance, assuming that this symmetry is preserved as well as in a four dimensional (4D) low energy effective field theory. As a concrete setup, we consider a modulus field $T$ whose contribution in the 4D effective field theory remains invariant under the modular transformation and study inflation drived by $T$. The modular invariance restricts a possible form of the scalar potenntial. As a result, large field models of inflation are hardly realized. Meanwhile, a small field model of inflation can be still accomodated in this restricted setup. The scalar potential traced during the slow-roll inflation mimics the hilltop potential $V_{ht}$, but it also has a non-negligible deviation from $V_{ht}$. Detecting the primordial gravitational waves predicted in this model is rather challenging. Yet, we argue that it may be still possible to falsify this model by combining the information in the reheating process which can be determined self-completely in this setup.

22 pages, 12 figures

References in corpus (8)

• More about F-term uplifting
• Higher Order Couplings in Magnetized Brane Models
• Modulated Natural Inflation
• Implications of the scalar tilt for the tensor-to-scalar ratio
• Higher Order Couplings from Heterotic Orbifold Theory
• Trajectories with suppressed tensor-to-scalar ratio in Aligned Natural Inflation
• New potentials for string axion inflation
• Natural inflation with and without modulations in type IIB string theory

Cited by in corpus (13)

• New $A_4$ lepton flavor model from $S_4$ modular symmetry
• $A_4$ lepton flavor model and modulus stabilization from $S_4$ modular symmetry
• Modular Flavor Symmetry on Magnetized Torus
• $CP$ violation in modular invariant flavor models
• Classification of discrete modular symmetries in Type IIB flux vacua
• Higgs-Modular Inflation
• Moduli inflation from modular flavor symmetries
• Inflation from periodic extra dimensions
• Moduli trapping mechanism in modular flavor symmetric models
• Modular Invariant Slow Roll Inflation
• Poly-instanton axion inflation
• Small field axion inflation with sub-Planckian decay constant
• Inflationary constraints on the moduli-dependent species scale in modular invariant theories