Axiverse cosmology and the energy scale of inflation

Abstract

Ultra-light axions ($m_a\lesssim 10^{-18}$eV), motivated by string theory, can be a powerful probe of the energy scale of inflation. In contrast to heavier axions the isocurvature modes in the ultra-light axions can coexist with observable gravitational waves. Here it is shown that large scale structure constraints severely limit the parameter space for axion mass, density fraction and isocurvature amplitude. It is also shown that radically different CMB observables for the ultra-light axion isocurvature mode additionally reduce this space. The results of a new, accurate and efficient method to calculate this isocurvature power spectrum are presented, and can be used to constrain ultra-light axions and inflation.

4 pages, 3 figures, v3 some references added, matches version published in Physical Review D

References in corpus (3)

• The type IIB string axiverse and its low-energy phenomenology
• An M Theory Solution to the Strong CP Problem and Constraints on the Axiverse
• Ultra-Light Scalar Fields and the Growth of Structure in the Universe

Cited by in corpus (22)

• Axion Cosmology
• CMB-S4 Science Case, Reference Design, and Project Plan
• Wave Dark Matter
• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• A Model For Halo Formation With Axion Mixed Dark Matter
• Using the Full Power of the Cosmic Microwave Background to Probe Axion Dark Matter
• Structure Formation and Microlensing with Axion Miniclusters
• Cosmological window onto the string axiverse and the supersymmetry breaking scale
• Relativistic scalar fields and the quasi-static approximation in theories of modified gravity
• Ultra-light axions and the $S_8$ tension: joint constraints from the cosmic microwave background and galaxy clustering
• An ultralight pseudoscalar boson
• Tensor Detection Severely Constrains Axion Dark Matter
• Late time transitions in the quintessence field and the $H_0$ tension
• Early Structure Formation Constraints on the Ultra-Light Axion in the Post-Inflation Scenario
• Constraints on primordial magnetic fields from CMB distortions in the axiverse
• The Spectrum of the Axion Dark Sector
• Schwarzschild scalar wigs: spectral analysis and late time behavior
• The future search for low-frequency axions and new physics with the FLASH resonant cavity experiment at Frascati National Laboratories
• How sound are our ultra-light axion approximations?
• Gravitational waves and neutrino oscillations in Chern-Simons axion gravity
• Constraining SUSY with Heavy Scalars -- using the CMB
• Searching for blue in the dark