Scale independent $R^2$ inflation

Abstract

Weyl (scale) invariant theories of scalars and gravity can generate all mass scales spontaneously. In this paper we study a particularly simple version -- scale invariant $R^2$ gravity -- and show that, during an inflationary period, it leads to fluctuations which, for a particular parameter choice, are almost indistinguishable from normal $R^2$ inflation. Current observations place tight constraints on the primary coupling constant of this theory and predict a tensor to scalar ratio, $0.0033>r>0.0026$, which is testable with the next generation of cosmic microwave background experiments.

References in corpus (19)

• The Standard Model Higgs boson as the inflaton
• The Simons Observatory: Science goals and forecasts
• Quantum scale invariance, cosmological constant and hierarchy problem
• Scale invariance, unimodular gravity and dark energy
• Frame-dependence of higher-order inflationary observables in scalar-tensor theories
• Weyl Current, Scale-Invariant Inflation and Planck Scale Generation
• Spontaneous breaking of Weyl quadratic gravity to Einstein action and Higgs potential
• Weyl gauge symmetry and its spontaneous breaking in Standard Model and inflation
• No fifth force in a scale invariant universe
• On the geometrical interpretation of scale-invariant models of inflation
• Frame Covariant Nonminimal Multifield Inflation
• Nonminimal Coleman--Weinberg Inflation with an $R^2$ term
• Higgs-Dilaton cosmology: Are there extra relativistic species?
• Higgs-Dilaton cosmology: Universality vs. criticality
• Implication of Compensator Field and Local Scale Invariance in the Standard Model
• Planck mass and inflation as consequences of dynamically broken scale invariance
• Inflation and reheating in scale-invariant scalar-tensor gravity
• Scale-invariant alternatives to general relativity. III. The inflation--dark-energy connection
• Standard Model and SU(5) GUT with Local Scale Invariance and the Weylon

Cited by in corpus (27)

• Dynamically induced Planck scale and inflation in the Palatini formulation
• Gauging scale symmetry and inflation: Weyl versus Palatini gravity
• Palatini quadratic gravity: spontaneous breaking of gauged scale symmetry and inflation
• Scale-Invariant Quadratic Gravity and Inflation in the Palatini Formalism
• Standard Model in Weyl conformal geometry
• Weyl $R^2$ inflation with an emergent Planck scale
• Non-metric geometry as the origin of mass in gauge theories of scale invariance
• Scale and Weyl Invariance in Einstein-Cartan Gravity
• Minimal $k$-inflation in light of the conformal metric-affine geometry
• Coupling Metric-Affine Gravity to the Standard Model and Dark Matter Fermions
• Weyl Scaling Invariant $R^2$ Gravity for Inflation and Dark Matter
• Inflation in Weyl-invariant Einstein-Cartan gravity
• A Walking Dilaton Inflation
• Inflation and primordial gravitational waves in scale-invariant quadratic gravity with Higgs
• Scale Invariant Gravity and Black Hole Ringdown
• Conformal $\alpha$-attractor Inflation with Weyl Gauge Field
• Inflation and dark matter after spontaneous Planck scale generation by hidden chiral symmetry breaking
• Dark Matter Production in Weyl $R^2$ Inflation
• Inflation in Weyl Scaling Invariant Gravity with $R^3$ Extensions
• Inflation and Scale-invariant $R^2$-Gravity
• Gravitational Waves from Preheating in Inflation with Weyl Symmetry
• Cosmological evolution in Weyl conformal geometry
• Spontaneous scale symmetry breaking at high temperature
• Post-Newtonian Binary Dynamics in Effective Field Theory of Horndeski Gravity
• Starobinksy Inflation, Gravitational Contact Terms and the Induced BEH Boson Mass
• Inflation in light of ACT/SPT: A new perspective from Weyl gravity
• Higgs-Dilaton Inflation in Einstein-Cartan gravity