CMB power spectrum for emergent scenario and slow expansion in scalar-tensor theory of gravity

Abstract

We analyze the stability of the Einstein static universe in scalar-tensor theory of gravity, and find it can be stable against both scalar and tensor perturbations under certain conditions. By assuming the emergent scenario originating from an Einstein static state, followed by an instantaneous transition to an inflationary phase, we study and obtain the analytical approximations of the primordial power spectrum for the emergent scenario. Then, we plot the primordial power spectrum and CMB TT-spectrum of the emergent scenario and the slow expansion scenario. These figures show that both of these spectra for the slow expansion scenario are the same as that for $\Lambda$CDM, and the spectra of the emergent scenario are lower than that for $\Lambda$CDM at large scales.

References in corpus (11)

• Just enough inflation: power spectrum modifications at large scales
• Emergent universe in a Jordan-Brans-Dicke theory
• Emergent Universe Scenario via Quintom Matter
• Gauge invariant cosmological perturbations for the nonminimally coupled inflaton field
• Emergent Universe from Energy-Momentum Squared Gravity
• Inhomogeneous Perturbations and Stability Analysis of the Einstein Static Universe in f(R,T) Gravity
• Stability of the Einstein static Universe in Einstein-Cartan-Brans-Dicke gravity
• Primordial power spectra from $k$-inflation with curvature
• CMB power spectrum in the emergent universe with k-essence
• Analytical approximations for primordial power spectra in a spatially closed emergent universe
• Emergent universe revisited through the CSL theory

Cited by in corpus (5)

• Emergent Universe in f(Q) gravity theories
• Holographic inflation and holographic dark energy from entropy of the anti-de Sitter black hole
• Evolution of the early universe in Einstein-Cartan theory
• Constant-roll inflation and primordial black holes within Barrow entropic framework
• Stability of the Einstein Static Universe in Zero-Point Length Cosmology with Topological Defects