Cosmological constraints on string scale and coupling arising from tachyonic instability

Abstract

We demonstrate that string motivated inflation ending via tachyonic instability leaves a detectable imprint on the cosmic microwave background (CMB) radiation by virtue of the excitation of non-Gaussian gravitational fluctuations. The present WMAP bound on non-Gaussianity is shown to constrain the string scale by $M_S/M_P\le 10^{-4}$ for string coupling $g_s<0.1$, hence improving the existing bounds. If tachyon fluctuations during inflation are not negligible, we find the stringent constraint $g_s\sim 10^{-9}$ for $M_S/M_P<10^{-3}$. This case may soon be ruled out by the forthcoming CMB non-Gaussinianity bounds.

12 pages, 2 figures, typo corrected, discussion and references added

References in corpus (33)

• de Sitter Vacua in String Theory
• Towards Inflation in String Theory
• Non-Gaussianity from Inflation: Theory and Observations
• Brane Inflation
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Tests of Gaussianity
• Second-Order Cosmological Perturbations from Inflation
• Cosmic String Production Towards the End of Brane Inflation
• Field Theory of Tachyon Matter
• The Inflationary Brane-Antibrane Universe
• Dynamics of Symmetry Breaking and Tachyonic Preheating
• Assisted inflation via tachyon condensation
• Racetrack Inflation
• D3/D7 Inflationary Model and M-theory
• On Exact Tachyon Potential in Open String Field Theory
• Inflation from D-\bar{D} brane annihilation
• Brane Interaction as the Origin of Inflation
• Inflationary Scenarios from Branes at Angles
• Observational Constraints on Cosmic String Production During Brane Inflation
• Remarks on Tachyon Condensation in Superstring Field Theory
• String Theory and Hybrid Inflation/Acceleration
• Non-Gaussianity from Preheating
• An Inflationary Model in String Theory
• Non-Gaussianity from Instant and Tachyonic Preheating
• Multiple Inflation, Cosmic String Networks and the String Landscape
• Recombination of Intersecting D-Branes and Cosmological Inflation
• Non-Gaussian perturbations in hybrid inflation
• Search for Cosmic Strings in CMB Anisotropies
• Overproduction of cosmic superstrings
• Inflation in warped geometries
• Accelerated expansion and the Goldstone ghost
• Braneworld inflation
• Long time scales and eternal black holes
• Non-Gaussianity in braneworld and tachyon inflation

Cited by in corpus (22)

• Particle physics models of inflation and curvaton scenarios
• Nongaussian and nonscale-invariant perturbations from tachyonic preheating in hybrid inflation
• Nongaussianity from Tachyonic Preheating in Hybrid Inflation
• Stringy Effects During Inflation and Reheating
• Primordial Non-Gaussianities of General Multiple Field Inflation
• Large Nongaussianity from Nonlocal Inflation
• Very Large Primordial Non-Gaussianity from multi-field: Application to Massless Preheating
• The hybrid inflation waterfall and the primordial curvature perturbation
• Supersymmetric Thermalization and Quasi-Thermal Universe: Consequences for Gravitinos and Leptogenesis
• Preheating and the non-gaussianity of the curvature perturbation
• Predictions for Nongaussianity from Nonlocal Inflation
• Combined local and equilateral non-Gaussianities from multifield DBI inflation
• On the evolution of tachyonic perturbations at super-Hubble scales
• Reheating in supersymmetric high scale inflation
• Contribution of the hybrid inflation waterfall to the primordial curvature perturbation
• Exciting gauge field and gravitons in a brane-anti-brane annihilation
• Brane Annihilations during Inflation
• Statistics of general functions of a Gaussian field -application to non-Gaussianity from preheating-
• Non-Gaussianity in KKLMMT model
• Revisiting non-Gaussianity of multiple-field inflation from the field equation
• The Origin of the Large-Scale Structure in the Universe: Theoretical and Statistical Aspects
• More on loops in reheating: Non-gaussianities and tensor power spectrum