(Slow-)Twisting inflationary attractors

Abstract

We explore in detail the dynamics of multi-field inflationary models. We first revisit the two-field case and rederive the coordinate independent expression for the attractor solution with either small or large turn rate, emphasizing the role of isometries for the existence of rapid-turn solutions. Then, for three fields in the slow-twist regime we provide elegant expressions for the attractor solution for generic field-space geometries and potentials and study the behaviour of first order perturbations. For generic $\mathcal{N}$-field models, our method quickly grows in algebraic complexity. We observe that field-space isometries are common in the literature and are able to obtain the attractor solutions and deduce stability for some isometry classes of $\mathcal{N}$-field models. Finally, we apply our discussion to concrete supergravity models. These analyses conclusively demonstrate the existence of $\mathcal{N}>2$ dynamical attractors distinct from the two-field case, and provide tools useful for future studies of their phenomenology in the cosmic microwave background and stochastic gravitational wave spectrum.

arXiv comment38 pages, 10 figures. v3: improved figures, minor changes

References in corpus (67)

• Planck 2018 results. X. Constraints on inflation
• Inflation Dynamics and Reheating
• The Swampland: Introduction and Review
• Distance and de Sitter Conjectures on the Swampland
• Cosmological perturbations
• N-flation
• De Sitter Space and the Swampland
• Bounds on Slow Roll and the de Sitter Swampland
• Features of heavy physics in the CMB power spectrum
• Scalar perturbations during multiple-field slow-roll inflation
• General inflaton potentials in supergravity
• Equilateral Non-Gaussianity and New Physics on the Horizon
• The Gelaton Scenario: Equilateral non-Gaussianity from multi-field dynamics
• Effective theories of single field inflation when heavy fields matter
• The string swampland constraints require multi-field inflation
• On the importance of heavy fields during inflation
• Heavy fields, reduced speeds of sound and decoupling during inflation
• Primordial Bispectrum from Multifield Inflation with Nonminimal Couplings
• The dS swampland conjecture and the Higgs potential
• Oscillations in the stochastic gravitational wave background from sharp features and particle production during inflation
• Strongly Coupled Perturbations in Two-Field Inflationary Models
• Geometrical Destabilization of Inflation
• Hyperinflation
• Further refining the de Sitter swampland conjecture
• Swampland Distance Conjecture, Inflation and $\alpha$-attractors
• Primordial fluctuations and non-Gaussianities in sidetracked inflation
• A Statistical Approach to Multifield Inflation: Many-field Perturbations Beyond Slow Roll
• Bounds on Slow Roll at the Boundary of the Landscape
• Inflation with moderately sharp features in the speed of sound: GSR and in-in formalism for power spectrum and bispectrum
• Primordial perturbations from inflation with a hyperbolic field-space
• Effective field theory of weakly coupled inflationary models
• Scaling attractors in multi-field inflation
• Simple predictions from multifield inflationary models
• Hyper non-Gaussianities in inflation with strongly non-geodesic motion
• Density perturbations arising from multiple field slow-roll inflation
• The rapid-turn inflationary attractor
• Cumulative effects in inflation with ultra-light entropy modes
• Angular inflation in multi-field $\alpha$-attractors
• Open problems on classical de Sitter solutions
• Revisiting non-Gaussianity in multifield inflation with curved field space
• Hyperinflation generalised: from its attractor mechanism to its tension with the `swampland conjectures'
• Sound Speed of Primordial Fluctuations in Supergravity Inflation
• On Perturbation Spectra of N-flation
• On the inflationary massive field with a curved field manifold
• Attractors, Bifurcations and Curvature in Multi-field Inflation
• Gravitational wave consistency relations for multifield inflation
• Cosmic inflation in a landscape of heavy-fields
• Multifield inflation beyond $N_{\mathrm{field}}=2$: non-Gaussianities and single-field effective theory
• Fat Inflatons, Large Turns and the $\eta$-problem
• Simple emergent power spectra from complex inflationary physics
• Multi-field Inflation in High-Slope Potentials
• Sgoldstino inflation
• Constraints on holographic multi-field inflation and models based on the Hamilton-Jacobi formalism
• Cosmological Solutions in Multiscalar Field Theory
• Dynamics of Chiral Cosmology
• Geometrical Destabilisation of Ultra-Light Axions in String Inflation
• The Multi-Field, Rapid-Turn Inflationary Solution
• Seven Lessons from Manyfield Inflation in Random Potentials
• Inflation in Multi-field Modified DBM Potentials
• The Strong Multifield Slowroll Condition and Spiral Inflation
• Predictions in multifield models of inflation
• $\mathcal{N}$-field cosmology in hyperbolic field space: stability and general solutions
• Dynamical consistency conditions for rapid turn inflation
• Many-field Inflation: Universality or Prior Dependence?
• Observational constraints on Hyperinflation
• Testing Two-Field Inflation
• Primordial Stochastic Gravitational Wave Backgrounds from a Sharp Feature in Three-field Inflation I: The Radiation Era

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