Axion Isocurvature Perturbations in Low-Scale Models of Hybrid Inflation

Abstract

The QCD axion solves the strong CP problem and represents an attractive particle candidate for cold dark matter (CDM). However, quantum fluctuations of the axion field during inflation easily result in large CDM isocurvature perturbations that are in conflict with observations of the cosmic microwave background (CMB). In this paper, we demonstrate how this problem can be solved in low-scale models of hybrid inflation that may emerge from supersymmetric grand unified theories. We consider both F-term hybrid inflation (FHI) and D-term hybrid inflation (DHI) in supergravity, explicitly taking into account the effect of hidden-sector supersymmetry breaking. We discuss the production of cosmic strings and show how the soft terms in the scalar potential readily allow to achieve the correct scalar spectral index. In both cases, we are able to identify large regions in parameter space that are consistent with all constraints. In particular, we find that evading the CDM isocurvature constraint always requires a small Yukawa or gauge coupling of O(10^-3) or smaller. This translates into upper bounds on the gravitino mass of O(10^5) GeV in FHI and O(10^9) GeV in DHI. Our results point to interesting scenarios in well-motivated parameter regions that will be tested in future axion and CMB experiments.

40 pages + references, 5 figures, 1 table. v2: typos removed, updated references. v3: matches version published in PRD

References in corpus (37)

• New experimental approaches in the search for axion-like particles
• Discovering the QCD Axion with Black Holes and Gravitational Waves
• Axions from Strings: the Attractive Solution
• The dark-matter axion mass
• Possible Signals of Wino LSP at the Large Hadron Collider
• The Stochastic Axion Scenario
• Unifying inflation with the axion, dark matter, baryogenesis and the seesaw mechanism
• Simply Unnatural Supersymmetry
• The QCD Axion Window and Low Scale Inflation
• Isocurvature bounds on axions revisited
• Constraints on Supersymmetric Models of Hybrid Inflation
• Comments on the Fayet-Iliopoulos Term in Field Theory and Supergravity
• Stochastic gravitational waves from cosmic string loops in scaling
• Implications of Supersymmetry Breaking with a Little Hierarchy between Gauginos and Scalars
• New CMB constraints for Abelian Higgs cosmic strings
• Fayet-Iliopoulos terms in supergravity without gauged R-symmetry
• Spontaneous B-L Breaking as the Origin of the Hot Early Universe
• Axion isocurvature fluctuations with extremely blue spectrum
• Lattice QCD for Cosmology
• Hybrid Inflation in the Complex Plane
• Taking a vector supermultiplet apart: Alternative Fayet-Iliopoulos-type terms
• Fayet-Iliopoulos terms in supergravity and D-term inflation
• Resonant conversions of QCD axions into hidden axions and suppressed isocurvature perturbations
• Matter and Dark Matter from False Vacuum Decay
• WIMP Dark Matter from Gravitino Decays and Leptogenesis
• Higgs inflation and suppression of axion isocurvature perturbation
• Constraint on the gravitino mass in hybrid inflation
• Relaxing Isocurvature Bounds on String Axion Dark Matter
• Inflation from High-Scale Supersymmetry Breaking
• The Chaotic Regime of D-Term Inflation
• A Hint of a Blue Axion Isocurvature Spectrum?
• Grand Unification and Subcritical Hybrid Inflation
• Dynamical D-Terms in Supergravity
• Superconformal Subcritical Hybrid Inflation
• A Bump in the Blue Axion Isocurvature Spectrum
• Domain wall and isocurvature perturbation problems in a supersymmetric axion model
• Reheating and Leptogenesis after Pati-Salam F-term Subcritical Hybrid Inflation

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• The Interplay between the Dark Matter Axion and Primordial Black Holes
• Trans-Planckian Censorship and Inflation in Grand Unified Theories
• Isocurvature bounds on axion-like particle dark matter in the post-inflationary scenario
• Post-inflationary axion isocurvature perturbations facing CMB and large-scale structure
• Standard model Higgs field and hidden sector cosmology
• Superconformal vector multiplet self-couplings and generalised Fayet-Iliopoulos terms
• Cosmic Strings from Tribrid Inflation
• Hitchhiker's Guide to the Swampland: The Cosmologist's Handbook to the string-theoretical Swampland Programme
• Affleck-Dine baryogenesis in the SUSY Dine-Fischler-Srednicki-Zhitnitsky axion model without R-parity
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